LundstrømLH, Duez CHV, Nørskov AK, Rosenstock CV, Thomsen JL,Møller AM, Strande S, Wetterslev JThe Cochrane database of systematic reviews 2017
BACKGROUND Tracheal intubation during induction of general anaesthesia is a vital procedure performed to secure a patient's airway. Several studies have identified difficult tracheal intubation (DTI) or failed tracheal intubation as one of the major contributors to anaesthesia-related mortality and morbidity. Use of neuromuscular blocking agents (NMBA) to facilitate tracheal intubation is a widely accepted practice. However, because of adverse effects, NMBA may be undesirable. Cohort studies have indicated that avoiding NMBA is an independent risk factor for difficult and failed tracheal intubation. However, no systematic review of randomized trials has evaluated conditions for tracheal intubation, possible adverse effects, and postoperative discomfort. OBJECTIVES To evaluate the effects of avoiding neuromuscular blocking agents (NMBA) versus using NMBA on difficult tracheal intubation (DTI) for adults and adolescents allocated to tracheal intubation with direct laryngoscopy. To look at various outcomes, conduct subgroup and sensitivity analyses, examine the role of bias, and apply trial sequential analysis (TSA) to examine the level of available evidence for this intervention. SEARCH METHODS We searched CENTRAL, MEDLINE, Embase, BIOSIS, International Web of Science, LILACS, advanced Google, CINAHL, and the following trial registries: Current Controlled Trials; ClinicalTrials.gov; and www.centerwatch.com, up to January 2017. We checked the reference lists of included trials and reviews to look for unidentified trials. SELECTION CRITERIA We included randomized controlled trials (RCTs) that compared the effects of avoiding versus using NMBA in participants 14 years of age or older. DATA COLLECTION AND ANALYSIS Two review authors extracted data independently. We conducted random-effects and fixed-effect meta-analyses and calculated risk ratios (RRs) and their 95% confidence intervals (CIs). We used published data and data obtained by contacting trial authors. To minimize the risk of systematic error, we assessed the risk of bias of included trials. To reduce the risk of random errors caused by sparse data and repetitive updating of cumulative meta-analyses, we applied TSA. MAIN RESULTS We identified 34 RCTs with 3565 participants that met our inclusion criteria. All trials reported on conditions for tracheal intubation; seven trials with 846 participants described 'events of upper airway discomfort or injury', and 13 trials with 1308 participants reported on direct laryngoscopy. All trials used a parallel design. We identified 18 dose-finding studies that included more interventions or control groups or both. All trials except three included only American Society of Anesthesiologists (ASA) class I and II participants, 25 trials excluded participants with anticipated DTI, and obesity or overweight was an excluding factor in 13 studies. Eighteen trials used suxamethonium, and 18 trials used non-depolarizing NMBA.Trials with an overall low risk of bias reported significantly increased risk of DTI with no use of NMBA (random-effects model) (RR 13.27, 95% CI 8.19 to 21.49; P < 0.00001; 508 participants; four trials; number needed to treat for an additional harmful outcome (NNTH) = 1.9, I(2) = 0%, D(2) = 0%, GRADE = moderate). The TSA-adjusted CI for the RR was 1.85 to 95.04. Inclusion of all trials resulted in confirmation of results and of significantly increased risk of DTI when an NMBA was avoided (random-effects model) (RR 5.00, 95% CI 3.49 to 7.15; P < 0.00001; 3565 participants; 34 trials; NNTH = 6.3, I(2) = 70%, D(2) = 82%, GRADE = low). Again the cumulative z-curve crossed the TSA monitoring boundary, demonstrating harmful effects of avoiding NMBA on the proportion of DTI with minimal risk of random error. We categorized only one trial reporting on upper airway discomfort or injury as having overall low risk of bias. Inclusion of all trials revealed significant risk of upper airway discomfort or injury when an NMBA was avoided (random-effects model) (RR 1.37, 95% CI 1.09 to 1.74; P = 0.008; 846 participants; seven trials; NNTH = 9.1, I(2) = 13%, GRADE = moderate). The TSA-adjusted CI for the RR was 1.00 to 1.85. None of these trials reported mortality. In terms of our secondary outcome 'difficult laryngoscopy', we categorized only one trial as having overall low risk of bias. All trials avoiding NMBA were significantly associated with difficult laryngoscopy (random-effects model) (RR 2.54, 95% CI 1.53 to 4.21; P = 0.0003; 1308 participants; 13 trials; NNTH = 25.6, I(2) = 0%, D(2)= 0%, GRADE = low); however, TSA showed that only 6% of the information size required to detect or reject a 20% relative risk reduction (RRR) was accrued, and the trial sequential monitoring boundary was not crossed. AUTHORS' CONCLUSIONS This review supports that use of an NMBA may create the best conditions for tracheal intubation and may reduce the risk of upper airway discomfort or injury following tracheal intubation. Study results were characterized by indirectness, heterogeneity, and high or uncertain risk of bias concerning our primary outcome describing difficult tracheal intubation. Therefore, we categorized the GRADE classification of quality of evidence as moderate to low. In light of defined outcomes of individual included trials, our primary outcomes may not reflect a situation that many clinicians consider to be an actual difficult tracheal intubation by which the patient's life or health may be threatened.
Comparison of effectiveness of two commonly used two-handed mask ventilation techniques on unconscious apnoeic obese adults
Fei, Blair,Rice et al. British Journal of Anaesthesia 2017
Background. Mask ventilation and tracheal intubation are basic techniques for airway management and mutually inclusive rescue measures to restore ventilation. The aim of this study was to compare the effectiveness of mask ventilation between two commonly used techniques of two-handed mask ventilation in obese unconscious apnoeic adults. Methods. Eighty-one obese adults received mask ventilation after induction using C-E clamp and modified V-E clamp tech- niques in a randomized crossover manner. Mechanical ventilation was provided using a pressure-control mode, at a rate of 10 bpm, with an inspiratory-to-expiratory time ratio of 1:2 and a pre-set plateau airway pressure of 20cm H2O. The primary outcome was expired tidal volume.
Results. The BMI for the subjects was 37 (SD 4.9) kgm?2. The failure rates for mask ventilation (tidal volume? anatomical dead space) were 44% for the C-E technique and 0% for the V-E technique (P<0.001). Tidal volume was significantly lower for the C-E than the V-E technique [371 (SD 345) vs 720 (244) ml, P<0.001]. The peak airway pressures were 21 (SD 1.5) cm H2O for the C-E technique and 21 (1.3) cm H2O for the V-E technique. Conclusions. Mask ventilation using the modified V-E technique is more effective than with the C-E technique in uncon- scious obese apnoeic adults. Subjects who fail ventilation with the C-E technique can be ventilated effectively with the V-E technique
Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival
IMPORTANCE Tracheal intubation is common during adult in-hospital cardiac arrest, but little is known about the association between tracheal intubation and survival in this setting.
OBJECTIVE To determine whether tracheal intubation during adult in-hospital cardiac arrest is associated with survival to hospital discharge.
DESIGN, SETTING, AND PARTICIPANTS Observational cohort study of adult patients who had an in-hospital cardiac arrest from January 2000through December 2014 included in the Get With The Guidelines–Resuscitation registry, a US-based multicenter registry of in-hospital cardiac arrest. Patients who had an invasive airway in place at the time of cardiac arrestwere excluded. Patients intubated at any given minute (from 0-15 minutes)were matched with patients at risk of being intubated within the same minute (ie, still receiving resuscitation) based on a time-dependent propensity score calculated from multiple patient, event, and hospital characteristics.
EXPOSURE Tracheal intubation during cardiac arrest.
MAIN OUTCOMES AND MEASURES The primary outcomewas survival to hospital discharge. Secondary outcomes included return of spontaneous circulation (ROSC) and a good functional outcome. A cerebral performance category score of 1 (mild or no neurological deficit) or 2 (moderate cerebral disability)was considered a good functional outcome.
RESULTS The propensity-matched cohortwas selected from 108079 adult patients at 668 hospitals. The median agewas 69 years (interquartile range, 58-79 years), 45073 patients (42%)were female, and 24256 patients (22.4%) survived to hospital discharge.Of 71615 patients (66.3%) who were intubated within the first 15 minutes, 43 314 (60.5%)were matched to a patient not intubated in the same minute. Survival was lower among patients whowere intubated compared with those not intubated: 7052 of 43 314 (16.3%) vs 8407 of 43 314 (19.4%), respectively (risk ratio [RR] = 0.84; 95%CI,0.81-0.87; P < .001). The proportion of patients with ROSC was lower among intubated patients than those not intubated: 25022 of 43 311 (57.8%) vs 25 685 of 43 310 (59.3%), respectively (RR = 0.97; 95%CI,0.96-0.99; P < .001). Good functional outcome was also lower among intubated patients than those not intubated: 4439 of 41868 (10.6%) vs 5672 of 41 733 (13.6%), respectively (RR = 0.78; 95%CI,0.75-0.81; P < .001). Although differences existed in prespecified subgroup analyses, intubation was not associated with improved outcomes in any subgroup.
CONCLUSIONS AND RELEVANCE Among adult patients with in-hospital cardiac arrest, initiation of tracheal intubation within any given minute during the first 15 minutes of resuscitation, compared with no intubation during that minute, was associated with decreased survival to hospital discharge. Although the study design does not eliminate the potential for confounding by indication, these findings do not support early tracheal intubation for adult in-hospital cardiac arrest.
Preoxygenation: Physiologic Basis, Benefits, and Potential Risks
Nimmagadda U, Salem MR, Crystal GJ. Preoxygenation: Physiologic Basis, Benefits, and Potential Risks. Anesth Analg. 2017 Feb;124(2):507-517
Preoxygenation before anesthetic induction and tracheal intubation is a widely accepted maneuver, designed to increase the body oxygen stores and thereby delay the onset of arterial hemoglobin desaturation during apnea. Because difficulties with ventilation and intubation are unpredictable, the need for preoxygenation is desirable in all patients. During emergence from anesthesia, residual effects of anesthetics and inadequate reversal of neuromuscular blockade can lead to hypoventilation, hypoxemia, and loss of airway patency. In accordance, routine preoxygenation before the tracheal extubation has also been recommended. The objective of this article is to discuss the physiologic basis, clinical benefits, and potential concerns about the use of preoxygenation. The effectiveness of preoxygenation is assessed by its efficacy and efficiency. Indices of efficacy include increases in the fraction of alveolar oxygen, increases in arterial oxygen tension, and decreases in the fraction of alveolar nitrogen. End points of maximal preoxygenation (efficacy) are an end-tidal oxygen concentration of 90% or an end-tidal nitrogen concentration of 5%. Efficiency of preoxygenation is reflected in the rate of decline in oxyhemoglobin desaturation during apnea. All investigations have demonstrated that maximal preoxygenation markedly delays arterial hemoglobin desaturation during apnea. This advantage may be blunted in high-risk patients. Various maneuvers have been introduced to extend the effect of preoxygenation. These include elevation of the head, apneic diffusion oxygenation, continuous positive airway pressure (CPAP) and/or positive end-expiratory pressure (PEEP), bilevel positive airway pressure, and transnasal humidified rapid insufflation ventilatory exchange. The benefit of apneic diffusion oxygenation is dependent on achieving maximal preoxygenation, maintaining airway patency, and the existence of a high functional residual capacity to body weight ratio. Potential risks of preoxygenation include delayed detection of esophageal intubation, absorption atelectasis, production of reactive oxygen species, and undesirable hemodynamic effects. Because the duration of preoxygenation is short, the hemodynamic effects and the accumulation of reactive oxygen species are insufficient to negate its benefits. Absorption atelectasis is a consequence of preoxygenation. Two approaches have been proposed to reduce the absorption atelectasis during preoxygenation: a modest decrease in the fraction of inspired oxygen to 0.8, and the use of recruitment maneuvers, such as CPAP, PEEP, and/or a vital capacity maneuver (all of which are commonly performed during the administration of anesthesia). Although a slight decrease in the fraction of inspired oxygen reduces atelectasis, it does so at the expense of a reduction in the protection afforded during apnea.
Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival
Andersen LW, Granfeldt A, Callaway CW, Bradley SM, Soar J, Nolan JP, Kurth T, Donnino MW; American Heart Association’s Get With The Guidelines–Resuscitation Investigators.. Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival. JAMA. 2017 Feb 7;317(5):494-506.
Importance Tracheal intubation is common during pediatric in-hospital cardiac arrest, although the relationship between intubation during cardiac arrest and outcomes is unknown. Objective To determine if intubation during pediatric in-hospital cardiac arrest is associated with improved outcomes. Design, Setting, and Participants Observational study of data from United States hospitals in the Get With The Guidelines-Resuscitation registry. Pediatric patients (<18 years) with index in-hospital cardiac arrest between January 2000 and December 2014 were included. Patients who were receiving assisted ventilation, had an invasive airway in place, or both at the time chest compressions were initiated were excluded. Exposures Tracheal intubation during cardiac arrest . Main Outcomes and Measures The primary outcome was survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and neurologic outcome. A favorable neurologic outcome was defined as a score of 1 to 2 on the pediatric cerebral performance category score. Patients being intubated at any given minute were matched with patients at risk of being intubated within the same minute (ie, still receiving resuscitation) based on a time-dependent propensity score calculated from multiple patient, event, and hospital characteristics. Results The study included 2294 patients; 1308 (57%) were male, and all age groups were represented (median age, 7 months [25th-75th percentiles, 21 days, 4 years]). Of the 2294 included patients, 1555 (68%) were intubated during the cardiac arrest. In the propensity score-matched cohort (n = 2270), survival was lower in those intubated compared with those not intubated (411/1135 [36%] vs 460/1135 [41%]; risk ratio [RR], 0.89 [95% CI, 0.81-0.99]; P = .03). There was no significant difference in return of spontaneous circulation (770/1135 [68%] vs 771/1135 [68%]; RR, 1.00 [95% CI, 0.95-1.06]; P = .96) or favorable neurologic outcome (185/987 [19%] vs 211/983 [21%]; RR, 0.87 [95% CI, 0.75-1.02]; P = .08) between those intubated and not intubated. The association between intubation and decreased survival was observed in the majority of the sensitivity and subgroup analyses, including when accounting for missing data and in a subgroup of patients with a pulse at the beginning of the event. Conclusions and Relevance Among pediatric patients with in-hospital cardiac arrest, tracheal intubation during cardiac arrest compared with no intubation was associated with decreased survival to hospital discharge. Although the study design does not eliminate the potential for confounding, these findings do not support the current emphasis on early tracheal intubation for pediatric in-hospital cardiac arrest.
Whether to Intubate During Cardiopulmonary Resuscitation: Conventional Wisdom vs Big Data.
Wong DT, Yee AJ, Leong SM, Chung F. The effectiveness of apneic oxygenation during tracheal intubation in various clinical settings: a narrative review. Can J Anaesth. 2017 Apr;64(4):416-427.
PURPOSE During the process of tracheal intubation, patients are apneic or hypoventilating and are at risk of becoming hypoxemic. This risk is especially high in patients with acute or chronic respiratory failure and accompanying compromised respiratory reserve. To address this concern, apneic oxygenation can be administered during tracheal intubation to aid in maintaining arterial oxygen saturation. The objective of this narrative review is to examine the utilization of apneic oxygenation within the operating room, intensive care unit (ICU), emergency department, and pre-hospital settings and to determine its efficacy compared with controls. SOURCE For this narrative review, we obtained pertinent articles using MEDLINE(®) (1946 to April 2016), EMBASE™ (1974 to April 2016), Google Scholar, and manual searches. Apneic oxygenation was administered using various techniques, including the use of nasal prongs, nasopharyngeal or endotracheal catheters, or laryngoscopes. PRINCIPAL FINDINGS First, all 12 operating room studies showed that apneic oxygenation significantly prolonged the duration to, and incidence of, desaturation. Second, two of the five ICU studies showed a significantly smaller decline in oxygen saturation with apneic oxygenation, with three studies showing no statistically significant difference vs controls. Lastly, two emergency department or pre-hospital studies showed that the use of apneic oxygenation resulted in a significantly lower incidence of desaturation and smaller declines in oxygen saturation. CONCLUSION Sixteen of the 19 studies showed that apneic oxygenation prolongs safe apneic time and reduces the incidence of arterial oxygen desaturation. Overall, studies in this review show that apneic oxygenation prolongs the time to oxygen desaturation during tracheal intubation. Nevertheless, the majority of the studies were small in size, and they neither measured nor were adequately powered to detect adverse respiratory events or other serious rare complications. Prolonged apneic oxygenation (with its consequent hypercarbia) can have risks and should be avoided in patients with conditions such as increased intracranial pressure, metabolic acidosis, hyperkalemia, and pulmonary hypertension.
BACKGROUND: Many emergency physicians gain familiarity with the laryngeal anatomy only during the brief view achieved during rapid sequence induction and intubation. Awake laryngoscopy in the emergency department (ED) is an important and clinically underutilized procedure.
DISCUSSION: Providing benefit to the emergency physician through a slow, controlled, and deliberate examination of the airway, awake laryngoscopy facilitates confidence in the high-risk airway and eases the evolution to intubation, should it be required. Emergency physicians possess all the tools and skills required to effectively perform this procedure, through either the flexible endoscopic or rigid approaches. The procedure can be conducted utilizing local anesthesia with or without mild sedation, such that patients protect their airway.
CONCLUSION: We discuss two clinical scenarios, indications/contraindications, patient selection, and steps to performing two approaches to awake laryngoscopy in the ED.
Studying the Safety and Performance of Rapid Sequence Intubation: Data Collection Method Matters
Andrea S Rinderknecht, Jenna R Dyas, Benjamin T Kerrey, Gary L Geis, Mona H Ho, Matthew R Mittiga
Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine 2016 December 15
OBJECTIVE: We sought to describe and compare chart and video review as data collection sources for the study of Emergency Department (ED) Rapid Sequence Intubation (RSI).
METHODS: This retrospective cohort study compares the availability and content of key RSI outcome and process data from two sources: chart and video data from 12 months of pediatric ED RSI. Key outcomes included adverse effects (oxyhemoglobin desaturation, physiologic changes, inadequate paralysis, vomiting), process components (number of laryngoscopy attempts, end-tidal CO2 detection), and timing data (duration of pre-oxygenation and laryngoscopy attempts).
RESULTS: We reviewed 566 documents from 114 cases with video data. Video review detected higher rates of adverse effects (67%) than did chart review (46%, p<0.0001), identifying almost twice the rate of desaturation noted in the chart (34%, vs 18%, p=0.0002). The performance and timing of key RSI processes were significantly more reliably available via video review (timing and duration of pre-oxygenation, as well as timing, duration, and number of laryngoscopy attempts, all p<0.05). Video review identified 221 laryngoscopy attempts, whereas chart review only identified 187.
CONCLUSIONS: When compared with video review for retrospective study of RSI in a pediatric ED, chart review significantly underestimated adverse effects, inconsistently contained data on important RSI process elements, rarely provided time data, and often conflicted with observations made on video review. Interpretation of and design of future studies of RSI should take into consideration the quality of the data source. This article is protected by copyright. All rights reserved.
Bystander cricothyroidotomy with household devices - A fresh cadaveric feasibility study
Christian Braun, Ulrich Kisser, Astrid Huber, Klaus Stelter
Resuscitation 2017, 110: 37-41
INTRODUCTION: In various motion pictures, medical TV shows and internet chatrooms, non-medical devices were presented as tools for life-saving cricothyroidotomies. However, there is uncertainty about whether it is possible for a bystander to perform a cricothyroidotomy and maintain gas exchange using improvised household items. This study examines the ability of bystanders to carry out an emergency cricothyroidotomy in fresh human cadavers using only a pocket knife and a ballpoint pen.
MATERIALS AND METHODS: Two commonly available pens and five different pocket knives were used. Ten participants with no or only basic anatomical knowledge had to choose one of the pens and one of the knives and were asked to perform a cricothyroidotomy as quickly as possible after a short introduction. Primary successful outcome was a correct placement of the pen barrel and was determined by the thoracic lifting in a mouth-to-pen resuscitation.
RESULTS: Eight (80%) participants performed a successful approach to the upper airway with a thoracic lifting at the end. Five participants performed a cricothyroidotomy and three performed an unintentional tracheotomy. Injuries to muscles and cartilage were common, but no major vascular damage was seen in the post-procedural autopsy. However, mean time in the successful group was 243s.
CONCLUSION: In this cadaveric model, bystanders with variable medical knowledge were able to establish an emergency cricothyroidotomy in 80% of the cases only using a pocketknife and a ballpoint pen. No major complications (particularly injuries of arterial blood vessels or the oesophagus) occurred. Although a pocket knife and ballpoint pen cricothyroidotomy seem a very extreme procedure for a bystander, the results of our study suggest that it is a feasible option in an extreme scenario.1 For a better outcome, the anatomical landmarks of the neck and the incision techniques should be taught in emergency courses.
A randomised controlled trial comparing transnasal humidified rapid insufflation ventilatory exchange (THRIVE) pre-oxygenation with facemask pre-oxygenation in patients undergoing rapid sequence induction of anaesthesia
F Mir, A Patel, R Iqbal, M Cecconi, S A R Nouraei
Anaesthesia 2016 December 30
Pre-oxygenation is an essential part of rapid sequence induction of general anaesthesia for emergency surgery, in order to increase the oxygen reservoir in the lungs. We performed a randomised controlled trial of transnasal humidified rapid insufflation ventilatory exchange (THRIVE) pre-oxygenation or facemask pre-oxygenation in patients undergoing emergency surgery. Twenty patients were allocated to each group. No patient developed arterial oxygen saturation < 90% during attempted tracheal intubation. Arterial blood gases were sampled from an arterial catheter immediately after intubation. The mean (SD) PaO2 was 43.7 (15.2) kPa in the THRIVE group vs. 41.9 (16.2) kPa in the facemask group (p = 0.722); PaCO2 was 5.8 (1.1) kPa in the THRIVE group vs. 5.6 (1.0) kPa in the facemask group (p = 0.631); arterial pH was 7.36 (0.05) in the THRIVE group vs. 7.34 (0.06) in the facemask group (p = 0.447). No airway rescue manoeuvres were needed, and there were no differences in the number of laryngoscopy attempts between the groups. In spite of this, patients in the THRIVE group had a significantly longer apnoea time of 248 (71) s compared with 123 (55) s in the facemask group (p < 0.001). Transnasal humidified rapid insufflation ventilatory exchange is a practicable method for pre-oxygenating patients during rapid sequence induction of general anaesthesia for emergency surgery; we found that it maintained an equivalent blood gas profile to facemask pre-oxygenation, in spite of a significantly longer apnoea time.
Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation
Lewis SR, Butler AR, Parker J, Cook TM, Smith AF. Cochrane Database Syst Rev. 2016 Nov 15
Successful tracheal intubation during general anaesthesia traditionally requires a line of sight to the larynx attained by positioning the head and neck and using a laryngoscope to retract the tongue and soft tissues of the floor of the mouth. Difficulties with intubation commonly arise, and alternative laryngoscopes that use digital and/or fibreoptic technology have been designed to improve visibility when airway difficulty is predicted or encountered. Among these devices, a rigid videolaryngoscope (VLS) uses a blade to retract the soft tissues and transmits a lighted video image to a screen.
Our primary objective was to assess whether use of videolaryngoscopy for tracheal intubation in adults requiring general anaesthesia reduces risks of complications and failure compared with direct laryngoscopy. Our secondary aim was to assess the benefits and risks of these devices in selected population groups, such as adults with obesity and those with a known or predicted difficult airway.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase on 10 February 2015. Our search terms were relevant to the review question and were not limited by outcomes. We carried out clinical trials register searches and forward and backward citation tracking. We reran the search on 12 January 2016; we added potential new studies of interest from the 2016 search to a list of 'Studies awaiting classification', and we will incorporate these studies into the formal review during the review update.
We considered all randomized controlled trials and quasi-randomized studies with adult patients undergoing laryngoscopy performed with a VLS or a Macintosh laryngoscope in a clinical, emergency or out-of-hospital setting. We included parallel and cross-over study designs.
Data collection and analysis
Two review authors independently assessed trial quality and extracted data, consulting a third review author to resolve disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias.
We included 64 studies identified during the 2015 search that enrolled 7044 adult participants and compared a VLS of one or more designs with a Macintosh laryngoscope. We identified 38 studies awaiting classification and seven ongoing studies. Of the 64 included studies, 61 included elective surgical patients, and three were conducted in an emergency setting. Among 48 studies that included participants without a predicted difficult airway, 15 used techniques to simulate a difficult airway. Seven recruited participants with a known or predicted difficult airway, and the remaining studies did not specify or included both predicted and not predicted difficult airways. Only two studies specifically recruited obese participants. It was not possible to blind the intubator to the device, and we noted a high level of inevitable heterogeneity, given the large number of studies.
Statistically significantly fewer failed intubations were reported when a VLS was used (Mantel-Haenszel (M-H) odds ratio (OR), random-effects 0.35, 95% confidence Interval (CI) 0.19 to 0.65; 38 studies; 4127 participants), and fewer failed intubations occurred when a VLS was used in participants with an anticipated difficult airway (M-H OR, random-effects 0.28, 95% CI 0.15 to 0.55; six studies; 830 participants). We graded the quality of this evidence as moderate on the basis of the GRADE system. Failed intubations were fewer when a VLS was used in participants with a simulated difficult airway (M-H OR, random-effects 0.18, 95% CI 0.04 to 0.77; nine studies; 810 participants), but groups with no predicted difficult airway provided no significant results (M-H OR, random-effects 0.61, 95% CI 0.22 to 1.67; 19 studies; 1743 participants).
Eight studies reported on hypoxia, and only three of these described any events; results showed no differences between devices for this outcome (M-H OR, random-effects 0.39, 95% CI 0.10 to 1.44; 1319 participants). Similarly, few studies reported on mortality, noting no differences between devices (M-H OR, fixed-effect 1.09, 95% CI 0.65 to 1.82; two studies; 663 participants), and only one study reporting on the occurrence of respiratory complications (78 participants); we graded these three outcomes as very low quality owing to lack of data. We found no statistically significant differences between devices in the proportion of successful first attempts (M-H OR, random-effects 1.27, 95% CI 0.77 to 2.09; 36 studies; 4731 participants) nor in those needing more than one attempt. We graded the quality of this evidence as moderate. Studies reported no statistically significant differences in the incidence of sore throat in the postanaesthesia care unit (PACU) (M-H OR, random-effects 1.00 (95% CI 0.73 to 1.38); 10 studies; 1548 participants) nor at 24 hours postoperatively (M-H OR random-effects 0.54, 95% CI 0.27 to 1.07; eight studies; 844 participants); we graded the quality of this evidence as moderate. Data combined to include studies of cross-over design revealed statistically significantly fewer laryngeal or airway traumas (M-H OR, random-effects 0.68, 95% CI 0.48 to 0.96; 29 studies; 3110 participants) and fewer incidences of postoperative hoarseness (M-H OR, fixed-effect 0.57, 95% CI 0.36 to 0.88; six studies; 527 participants) when a VLS was used. A greater number of laryngoscopies performed with a VLS achieved a view of most of the glottis (M-H OR, random-effects 6.77, 95% CI 4.17 to 10.98; 22 studies; 2240 participants), fewer laryngoscopies performed with a VLS achieved no view of the glottis (M-H OR, random-effects 0.18, 95% CI 0.13 to 0.27; 22 studies; 2240 participants) and the VLS was easier to use (M-H OR, random-effects 7.13, 95% CI 3.12 to 16.31; seven studies; 568 participants).
Although a large number of studies reported time required for tracheal intubation (55 studies; 6249 participants), we did not present an effects estimate for this outcome owing to the extremely high level of statistical heterogeneity (I2 = 96%).
Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a VLS reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a VLS affects time required for intubation.
Prediction of difficult mask ventilation using a systematic assessment of risk factors vs. existing practice - a cluster randomised clinical trial in 94,006 patients
A K Nørskov, J Wetterslev, C V Rosenstock, A Afshari, G Astrup, J C Jakobsen, J L Thomsen, L H Lundstrøm Anaesthesia 2016 November 24
We compared implementation of systematic airway assessment with existing practice of airway assessment on prediction of difficult mask ventilation. Twenty-six departments were cluster-randomised to assess eleven risk factors for difficult airway management (intervention) or to continue with their existing airway assessment (control). In both groups, patients predicted as a difficult mask ventilation and/or difficult intubation were registered in the Danish Anaesthesia Database, with a notational summary of airway management. The trial's primary outcome was the respective incidence of unpredicted difficult and easy mask ventilation in the two groups. Among 94,006 patients undergoing mask ventilation, the incidence of unpredicted difficult mask ventilation in the intervention group was 0.91% and 0.88% in the control group; (OR) 0.98 (95% CI 0.66-1.44), p = 0.90. The incidence of patients predicted difficult to mask ventilate, but in fact found to be easy ('falsely predicted difficult') was 0.64% vs. 0.35% (intervention vs. control); OR 1.56 (1.01-2.42), p = 0.045. In the intervention group, 86.3% of all difficult mask ventilations were not predicted, compared with a higher proportion 91.2% in the control group, OR 0.61 (0.41-0.91), p = 0.016. The systematic intervention did not alter the overall incidence of unpredicted difficult mask ventilations, but of the patients who were found to be difficult to mask ventilate, the proportion predicted was higher in the intervention group than in the control group. However, this was at a 'cost' of increasing the number of mask ventilations falsely predicted to be difficult.
Flush Rate Oxygen for Emergency Airway Preoxygenation
Brian E. Driver, Matthew E. Prekker, Rebecca L. Kornas, Ellen K. Cales, Robert F. Reardon. Annals of Emergency Medicine 2016.
Study objective: Recent data suggest that emergency airway preoxygenation with a bag-valve-mask (BVM) device (held with a tight mask seal but without squeezing the bag) is superior to a nonrebreather (NRB) mask at standard oxygen flow rates. We seek to determine whether preoxygenation with an NRB mask with flush rate oxygen (>40 L/min by fully opening a standard oxygen flowmeter) is noninferior to BVM device with standard-flow oxygen (15 L/min). We also seek to compare the efficacy of preoxygenation with NRB mask at flush rate oxygen with both NRB mask with oxygen at 15 L/min and simple mask at flush rate oxygen. Methods: We performed a crossover trial using healthy volunteers. In random sequence, subjects underwent 3-minute trials of preoxygenation with nonrebreather mask with oxygen at 15 L/min (NRB-15), nonrebreather mask with flush rate oxygen (NRB-Flush), BVM device with oxygen at 15 L/min (BVM-15), and simple mask with flush rate oxygen. The primary outcome measure was the FeO2 in a single exhaled breath. We compared the FeO2 of NRB-Flush to other study groups, using a prespecified noninferiority margin of 10%. Results: We enrolled 26 subjects. Mean FeO2 values for NRB-15, NRB-Flush, BVM-15, and simple mask with flush rate oxygen were 54% (95% confidence interval [CI] 50% to 57%), 86% (95% CI 84% to 88%), 77% (95% CI 74% to 81%), and 72% (95% CI 69% to 76%), respectively. FeO2 for NRB-Flush was noninferior to BVM-15 (difference 8%; 95% CI 5% to 11%). FeO2 for NRB-Flush was higher than both NRB-15 (FeO2 difference 32%; 95% CI 29% to 35%) and simple mask with flush rate oxygen (FeO2 difference 13%; 95% CI 10% to 17%). Conclusion: Preoxygenation with NRB-Flush was noninferior to BVM-15. NRB with flush rate oxygen may be a reasonable preoxygenation method for spontaneously breathing patients undergoing emergency airway management.
Strategies to improve first attempt success at intubation in critically ill patients
B. S. Natt, J. Malo, C. D. Hypes, J. C. Sakles and J. M. Mosier. British Journal of Anaesthesia, 117 (S1): i60–i68 (2016)
Tracheal intubation in critically ill patients is a high-risk procedure. The risk of complications increases with repeated or prolonged attempts, making expedient first attempt success the goal for airway management in these patients. Patient-related factors often make visualization of the airway and placement of the tracheal tube difficult. Physiologic derangements reduce the patient’s tolerance for repeated or prolonged attempts at laryngoscopy and, as a result, hypoxaemia and haemodynamic deterioration are common complications. Operator-related factors such as experience, device selection, and pharmacologic choices affect the odds of a successful intubation on the first attempt. This review will discuss the ‘difficult airway’ in critically ill patients and highlight recent advances in airway management that have been shown to improve first attempt success and decrease adverse events associated with the intubation of critically ill patients.
Paediatric difficult airway management: what every anaesthetist should know!
N. Jagannathan, L. Sohn and J. E. Fiadjoe. British Journal of Anaesthesia 117 (S1): i3–i5 (2016)
Airway management remains a significant cause of morbidity and mortality in anaesthetized children. Children with difficult direct laryngoscopy are an especially vulnerable group. However, most paediatric anaesthetics are administered by generalists without advanced paediatric training. This editorial is aimed at all practitioners who care for children, particularly those without advanced paediatric anaesthesia training. Our goal is to convey three important points: (i) the contributing factors for severe complications in this population; (ii) the important role of the supraglottic airway (SGA) in managing these patients; and (iii) the ideal method of invasive airway access when oxygenation is compromised. We hope this editorial enhances the care and out- comes in this vulnerable patient population.
The great airway debate: is the scalpel mightier than the cannula?
P. A. Baker, E. P. O’Sullivan, M. S. Kristensen and D. Lockey. British Journal of Anaesthesia 117 (S1): i17–i19 (2016)
The emergency nature and infrequency of CICO and invasive rescue techniques make it unlikely that high-quality human studies will ever be available to support our choice of techniques. However, what is clear from observational studies is that cannula techniques cannot be relied upon to save lives and prevent severe morbidity. With appropriate training, scalpel techniques are reli- able and easy to perform and have the potential to reduce mortal- ity and morbidity in time-critical airway emergencies.
Siobal, M. S. Respiratory Care. September 2016
In the past few decades, assessment of exhaled CO2 in both intubated and non-intubated patients has evolved into an essential component in many aspects of patient monitoring. Besides the basic assessment of ventilation, exhaled CO2 monitoring can provide valuable patient safety information and critical physiologic data in regard to the ventilation and perfusion matching in the lungs, cardiac output, and metabolic rate. Despite these important clinical monitoring benefits and wide-spread availability, exhaled CO2 monitoring is often underutilized. The purpose of this paper is to review the importance and present the extensive body of knowledge to support the use of exhaled CO2 monitoring in various areas of clinical practice. Advanced application concepts and the future development of exhaled CO2 monitoring will also be discussed.
S. J. Mercer, C. P. Jones1, M. Bridge, E. Clitheroe, B. Morton and P. Groom British Journal of Anaesthesia, 117 (S1): i49–i59 (2016)
Introduction: Non-iatrogenic trauma to the airway is rare and presents a significant challenge to the anaesthetist. Although guidelines for the management of the unanticipated difficult airway have been published, these do not make provision for the ‘anticipated’ difficult airway. This systematic review aims to inform best practice and suggest management options for different injury patterns. Methods: A literature search was conducted using Embase, Medline, and Google Scholar for papers after the year 2000 reporting on the acute airway management of adult patients who suffered airway trauma. Our protocol and search strategy are registered with and published by PROSPERO (http://www.crd.york.ac.uk/PROSPERO, ID: CRD42016032763). Results: A systematic literature search yielded 578 articles, of which a total of 148 full-text papers were reviewed.We present our results categorized by mechanism of injury: blunt, penetrating, blast, and burns. Conclusions: The hallmark of airway management with trauma to the airway is the maintenance of spontaneous ventilation, intubation under direct vision to avoid the creation of a false passage, and the avoidance of both intermittent positive pressure ventilation and cricoid pressure (the latter for laryngotracheal trauma only) during a rapid sequence induction. Management depends on available resources and time to perform airway assessment, investigations, and intervention (patients will be classified into one of three categories: no time, some time, or adequate time).Humanfactors, particularly the development of a shared mental model amongst the trauma team, are vital to mitigate risk and improve patient safety.
Seeing is believing: getting the best out of videolaryngoscopy
F. E. Kelly and T. M. Cook British Journal of Anaesthesia 117 (S1): i9–i13 (2016)
In summary, videolaryngoscopy is a potential step change advance in anaesthesia, but its introduction needs to be accom- panied by appropriate training of all anaesthetists; not only trai- nees, but also trained and experienced intubators. The potential benefits of videolaryngoscopy for patients are numerous and significan
Role of upper airway ultrasound in airway management
Adi Osman, Kok Meng Sum. Journal of Intensive Care 2016, 4: 52
Upper airway ultrasound is a valuable, non-invasive, simple, and portable point of care ultrasound (POCUS) for evaluation of airway management even in anatomy distorted by pathology or trauma. Ultrasound enables us to identify important sono anatomy of the upper airway such as thyroid cartilage, epiglottis, cricoid cartilage, cricothyroid membrane, tracheal cartilages, and esophagus. Understanding this applied sono anatomy facilitates clinician to use ultrasound in assessment of airway anatomy for difficult intubation, ETT and LMA placement and depth, assessment of airway size, ultrasound-guided invasive procedures such as percutaneous needle cricothyroidotomy and tracheostomy, prediction of post extubation stridor and left double-lumen bronchial tube size, and detecting upper airway pathologies. Widespread POCUS awareness, better technological advancements, portability, and availability of ultrasound in most critical areas facilitate upper airway ultrasound to become the potential first-line non-invasive airway assessment tool in the future.
Managing Initial Mechanical Ventilation in the Emergency Department
Weingart S, Sutherasan Y, Vargas M et al. Ann Emerg Med 2016
The full complexity of ventilator management is best left to treatises of greater length than this one.8,9 However, the practices described will provide a safe path through the initial stages of ventilator management. By taking over one of the primary physiologic processes of our patients, we shoulder an enormous responsibility. A meticulous approach to ventilator management will keep those we care for safe until they can recover. Descriptions of the above strategies can be found on the EMCrit Podcast (http://emcrit.org/vent).
The Utility of the CMAC as a Direct Laryngoscope for Intubation in the ED
John C. Sakles, Jarrod M. Mosier, Asad E. Patanwala, Brittany Arcaris, and John M. Dicken. The Journal of Emergency Medicine, Vol.-, No.-, pp. 1–9, 2016.
Background: Although the C-MAC (Karl Storz, Tuttlingen, Germany) is a video laryngoscope (VL), it can also be used as a direct laryngoscope (DL). Objective: The goal of this study was to evaluate the utility of the C-MAC as a DL for intubations in the emergency depart- ment (ED). Methods: This was an analysis of prospectively collected continuous quality-improvement data during the 6-year period from February 1, 2009 to January 31, 2015, when both the C-MAC and Macintosh DL (Mac DL) were clinically available in our ED. This analysis included adult patients who underwent rapid sequence intubation by an emergency medicine resident in the ED with a C-MAC initially used as a DL or a Mac DL. The primary outcome measure was the first pass success (FPS). Results: When the C-MAC was used as a DL, the initial DL attempt was successful in 199 of 346 (57.6%) cases. When the attempt could not be completed using the C-MAC as a DL, the oper- ator utilized the video monitor and successfully completed the intubation using VL in 104 of 134 (77.6%) cases, thus achieving an overall FPS of 303 of 346 (87.6%). When the Mac DL was used, the FPS was 505 of 671 (75.3%). Conclu- sions: The C-MAC is a useful device for DL because in the event of a failed DL attempt, operators have the option of switching to the video monitor to successfully complete the intubation using VL without having to make a second attempt.
The Vortex: a universal ‘high-acuity implementation tool’ for emergency airway management
Chrimes N. British Journal of Anaesthesia, 2016, 1–8
Factors influencing performance during emergency airway management can be broadly divided into issues with preparation and those with implementation. Effective design of resources that provide guidance on management requires consideration of the context in which they are to be used. Many of the major airway guidelines do not specify whether they are intended to be used during preparation or implementation and may not take the context for use into account in their design. This can produce tools which may be not only ineffective but actively disruptive to team function in an emergency. TheVortex is a novel, simple, and predominantly visually based cognitive aid, which has been specifically designed to be used in real time during airway emergencies to support team function and target recognized failings in airway crisis management. Unlike the major algorithms, which are context specific, the Vortex is flexible enough for the same tool to be applied to any circumstance in which airway management takes place, independent of context, patient type, or the intended airway device. This makes the same tool suitable for use by emergency physicians, intensivists, paramedical staff, and anaesthetists. The Vortex contains many of the recognized features of an ideal cognitive tool and may be effective in reducing implementation errors in emergency airway management. Experimental evidence is required to establish this.
A national survey of the impact of NAP4 on airway management practice in United Kingdom hospitals: closing the safety gap in anaesthesia, intensive care and the emergency department
T. M. Cook, N.Woodall and C. Frerk. British Journal of Anaesthesia, 117 (2): 182–90 (2016)
Background: The 4th National Audit Project of the Royal College of Anaesthetists’ and Difficult Airway Society (NAP4) made recommendations to improve reliability and safety of airway management in hospitals. This survey examines its impact. Methods: A survey was sent to allUKNational Health Service hospitals to examine changes in practice in response to NAP4.We performed a ‘gap analysis’ to determine whether NAP4 had reduced the ‘safety gap’ between actual and ideal practice. Results: The response rate was 62% (192 of 307 hospitals), and 78% answered all questions. Most (97%) respondents reported changes in practice in response to NAP4 but these differed by specialty: 95% in anaesthesia; 80% in intensive care (ICU) and 59% in the emergency department (ED). Approximately25%reported changes in organizational aspects of airway and human factors teaching. Practice changes led to a median closure of the ‘safety gap’ in anaesthesia of 39% (IQR 14–66%, range 11–83%), 59% in ICU (IQR 54–73%, range 31–81%) and 48% in ED (IQR 39–53%, range 35–53%). Conclusions: Publication of NAP4was followed by changes in practice in the majority of responding departments within two yr. Improvements included improved provision of difficult airway equipment and more widespread routine use of capnography. The biggest change occurred in ICU; the impact on training nursing and junior staff was modest and here, significant safety gaps remain.
Deficiencies in locating the cricothyroid membrane by palpation: We can’t and the surgeons can’t, so what now for the emergency surgical airway?
Law, John A. Editorial: Canadian Journal of Anesthesia 2016
With good decision-making in the anticipated difficult airway situation and a well thought out approach to the unanticipated difficult airway, the need for establishing an ESA will continue to remain a rare event. Nevertheless, this will always be a double-edged sword—i.e., good that we may never have to do it, but bad in that we’ll never have a chance to master it through experience. This means that, both mentally19 and in simulation sessions, we must continue to rehearse the management techniques of a CICO scenario, including optimizing face mask ventilation; placing a supraglottic device, if not already attempted; ensuring pharmacologic paralysis if there is no prospect of a timely return to spontaneous ventilation; and performing ESA without delay.6 Furthermore, when informed by the results of continuing investigations, we must continue to adapt to emerging evidence by modifying existing guidelines and recommendations where needed
The Myth of Rescue Reversal in "Can't Intubate, Can't Ventilate" Scenarios
Mohamed Naguib, Lara Brewer, Cristen LaPierre, Aaron F Kopman, Ken B Johnson
Anesthesia and Analgesia 2016 May 2
BACKGROUND: An unanticipated difficult airway during induction of anesthesia can be a vexing problem. In the setting of can't intubate, can't ventilate (CICV), rapid recovery of spontaneous ventilation is a reasonable goal. The urgency of restoring ventilation is a function of how quickly a patient's hemoglobin oxygen saturation decreases versus how much time is required for the effects of induction drugs to dissipate, namely the duration of unresponsiveness, ventilatory depression, and neuromuscular blockade. It has been suggested that prompt reversal of rocuronium-induced neuromuscular blockade with sugammadex will allow respiratory activity to recover before significant arterial desaturation. Using pharmacologic simulation, we compared the duration of unresponsiveness, ventilatory depression, and neuromuscular blockade in normal, obese, and morbidly obese body sizes in this life-threatening CICV scenario. We hypothesized that although neuromuscular function could be rapidly restored with sugammadex, significant arterial desaturation will occur before the recovery from unresponsiveness and/or central ventilatory depression in obese and morbidly obese body sizes.
METHODS: We used published models to simulate the duration of unresponsiveness and ventilatory depression using a common induction technique with predicted rates of oxygen desaturation in various size patients and explored to what degree rapid reversal of rocuronium-induced neuromuscular blockade with sugammadex might improve the return of spontaneous ventilation in CICV situations.
RESULTS: Our simulations showed that the duration of neuromuscular blockade was longer with 1.0 mg/kg succinylcholine than with 1.2 mg/kg rocuronium followed 3 minutes later by 16 mg/kg sugammadex (10.0 vs 4.5 minutes). Once rocuronium neuromuscular blockade was completely reversed with sugammadex, the duration of hemoglobin oxygen saturation >90%, loss of responsiveness, and intolerable ventilatory depression (a respiratory rate of ≤4 breaths/min) were dependent on the body habitus and duration of oxygen administration. There is a high probability of intolerable ventilatory depression that extends well beyond the time when oxygen saturation decreases <90%, especially in obese and morbidly obese patients. If ventilatory rescue is inadequate, oxygen desaturation will persist in the latter groups, despite full reversal of neuromuscular blockade. Depending on body habitus, the duration of intolerable ventilatory depression after sugammadex reversal may be as long as 15 minutes in 5% of individuals.
CONCLUSIONS: The clinical management of CICV should focus primarily on restoration of airway patency, oxygenation, and ventilation consistent with the American Society of Anesthesiologist's practice guidelines for management of the difficult airway. Pharmacologic intervention cannot be relied upon to rescue patients in a CICV crisis.
Airway management in the critically ill: the same, but different
A Higgs, T M Cook, B A McGrath
British Journal of Anaesthesia 2016 May 4
The development of new guidelines
Current anaesthetic guidelines for management of airway difficulty are not universally applicable to the critical care setting. There have been appropriate calls for guidance specific to critical care and currently no such national guidelines exist.10 27 As part of the Royal College of Anaesthetists and The Difficult Airway Society’s (DAS) response to NAP4, a multidisciplinary working party with representation from the Faculty of Intensive Care Medicine, The Intensive Care Society, DAS, the National Tracheostomy Safety Project, the British Association of Critical Care Nursing and the College is currently drafting such guidance. Further de- tails of the project can be found at www.das.uk.com. We antici- pate the guidance will be available in 2017.
A deliberately restricted laryngeal view with the GlideScope® video laryngoscope is associated with faster and easier tracheal intubation when compared with a full glottic view: a randomized clinical trial
Yuqi Gu, Joshua Robert, George Kovacs, Andrew D Milne, Ian Morris, Orlando Hung, Kirk MacQuarrie, Sean Mackinnon, J Adam Law
Canadian Journal of Anaesthesia, Journal Canadien D'anesthésie 2016 April 18
INTRODUCTION: During video laryngoscopy (VL) with angulated or hyper-curved blades, it is sometimes difficult to complete tracheal intubation despite a full view of the larynx. When using indirect VL, it has been suggested that it may be preferable to obtain a deliberately restricted view of the larynx to facilitate passage of the endotracheal tube. We used the GlideScope® GVL video laryngoscope (GVL) to test whether deliberately obtaining a restricted view would result in faster and easier tracheal intubation than with a full view of the larynx.
METHODS: We recruited 163 elective surgical patients and randomly allocated the participants to one of two groups: Group F, where a full view of the larynx was obtained and held during GVL-facilitated tracheal intubation, and Group R, with a restricted view of the larynx (< 50% of glottic opening visible). Study investigators experienced in indirect VL performed the intubations. The intubations were recorded and the video recordings were subsequently assessed for total time to intubation, ease of intubation using a visual analogue scale (VAS; where 0 = easy and 100 = difficult), first-attempt success rate, and oxygen saturation after intubation. Complications were also assessed.
RESULTS: The median [interquartile range (IQR)] time to intubation was faster in Group R than in Group F (27 [22-36] sec vs 36 [27-48] sec, respectively; median difference, 9 sec; 95% confidence interval [CI], 5 to 13; P < 0.001). The median [IQR] VAS rating for ease of intubation was also better in Group R than in Group F (14 [6-42) mm vs 50 mm [17-65], respectively; median difference, 20 mm; 95% CI, 10 to 31; P < 0.001). There was no difference between groups regarding the first-attempt success rate, oxygen saturation immediately after intubation, or complications.
CONCLUSIONS: Using the GVL with a deliberately restricted view of the larynx resulted in faster and easier tracheal intubation than with a full view and with no additional complications. Our study suggests that obtaining a full or Cormack-Lehane grade 1 view may not be desirable when using the GVL. This trial was registered at ClinicalTrials.gov: NCT02144207.
Assessment of Common Preoxygenation Strategies Outside of the Operating Room Environment
Christopher Groombridge, Cheau Wern Chin, Bernard Hanrahan, Anna Holdgate
Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine 2016 January 4
OBJECTIVES: Preoxygenation prior to intubation aims to increase the duration of safe apnea by causing denitrogenation of the functional residual capacity, replacing this volume with a reservoir of oxygen. In the operating room (OR) the criterion-standard for preoxygenation is an anesthetic circuit and well-fitting face mask, which provide a high fractional inspired oxygen concentration (FiO2 ). Outside of the OR, various strategies exist to provide preoxygenation. The objective was to evaluate the effectiveness of commonly used preoxygenation strategies outside of the OR environment.
METHODS: This was a prospective randomized unblinded study of 30 healthy staff volunteers from a major trauma center emergency department (ED) in Sydney, Australia. The main outcome measure is fractional expired oxygen concentration (FeO2 ) measured after a 3 minute period of tidal volume breathing with seven different preoxygenation strategies.
RESULTS: The mean FeO2 achieved with the anesthetic circuit was 81.0% (95% CI = 78.3% to 83.6%), bag-valve-mask (BVM) 80.1% (95% CI = 76.5% to 83.6%), BVM with nasal cannulae (NC) 74.8% (95% CI = 72.0% to 77.6%), BVM with positive end expiratory pressure valve (PEEP) 78.9% (95% CI = 75.4% to 82.3%), BVM + NC + PEEP 75.5% (95% CI = 72.2% to 78.9%), non-rebreather mask (NRM) 51.6% (95% CI = 48.8% to 54.4%), and NRM + NC 57.1% (95% CI = 52.9% to 61.2%). Preoxygenation efficacy with BVM strategies was significantly greater than NRM strategies (p < 0.01), and non-inferior to the anesthetic circuit.
CONCLUSIONS: In healthy volunteers, the effectiveness of BVM preoxygenation was comparable to the anesthetic circuit (criterion standard), and superior to preoxygenation with NRM. The addition of nasal cannulae oxygen, PEEP, or both, did not improve the efficacy of the BVM device. This article is protected by copyright. All rights reserved.
Efficacy of Nasal Cannula Oxygen as a Preoxygenation Adjunct in Emergency Airway Management
Clare Hayes-Bradley, Anthony Lewis, Brian Burns, Matt Miller
Annals of Emergency Medicine 2015 December 31
STUDY OBJECTIVE: Although preoxygenation for emergency airway management is usually performed with nonrebreather face masks or bag-valve-mask devices, some clinicians also deliver supplemental high-flow oxygen by nasal cannula. We aim to measure the efficacy of supplemental nasal cannula oxygen delivery to conventional bag-valve-mask and nonrebreather face mask preoxygenation both with and without a simulated face mask leak.
METHODS: We conducted a randomized crossover trial using healthy volunteers. We randomized subjects to preoxygenation with bag-valve-mask or nonrebreather face mask. In random sequence, subjects underwent 3-minute trials of preoxygenation with oxygen through mask alone at 15 L/min, oxygen through mask at 15 L/min with standardized leak, oxygen through mask at 15 L/min+oxygen through nasal cannula at 10 L/min, and oxygen through mask at 15 L/min+oxygen through nasal cannula at 10 L/min with standardized leak. The primary outcome was single-breath exhalation end-tidal oxygen (eto2). We compared eto2 between preoxygenation modalities, using nonparametric techniques.
RESULTS: We enrolled 60 subjects (30 nonrebreather face mask and 30 bag-valve-mask). In scenarios without a mask leak, eto2 was similar between bag-valve-mask and bag-valve-mask+nasal cannula (mean 79% versus 75%; difference -3%; 95% confidence interval [CI] -8% to 1%). In bag-valve-mask scenarios with a mask leak, eto2 was higher for bag-valve-mask+nasal cannula than bag-valve-mask alone (mean 66% versus 41%; difference 25%; 95% CI 21% to 29%). eto2 was higher for nonrebreather face mask+nasal cannula than nonrebreather face mask (mean 67% versus 52%; difference 15%; 95% CI 12% to 18%). In nonrebreather face mask scenarios with a mask leak, eto2 was higher for nonrebreather face mask+nasal cannula than nonrebreather face mask (mean 65% versus 48%; difference 17%; 95% CI 13% to 20%).
CONCLUSION: Although not aiding bag-valve-mask preoxygenation with a good mask seal, supplemental nasal cannula oxygen improved preoxygenation efficacy in the presence of a bag-valve-mask mask leak. Supplemental nasal cannula oxygen improved nonrebreather face mask preoxygenation both with and without a mask leak. Supplemental nasal cannula oxygen may be helpful for preoxygenation before emergency airway management.
Ventilator-assisted preoxygenation: Protocol for combining non-invasive ventilation and apnoeic oxygenation using a portable ventilator
Steven Grant, Faisal Khan, Gerben Keijzers, Mark Shirran, Leo Marneros
Emergency Medicine Australasia: EMA 2016 January 14
OBJECTIVE: To describe a simple protocol for ventilator-assisted preoxygenation (VAPOX) prior to rapid sequence intubation in the ED using a Hamilton T1 ventilator in an effort to further reduce the incidence of transient and critical hypoxaemia.
METHODS: Ventilator-assisted preoxygenation includes the following steps; preparation for rapid sequence intubation as per institutional protocols, including departmental checklists. Hamilton T1 ventilator is setup in non-invasive spontaneous/timed mode with settings as described. The patient is optimally positioned and nasal cannula applied with an oxygen flow rate of 15 L/min. A face mask is applied with the jaw pulled forward using a two-handed thenar eminence grip and the ventilator is started. Preoxygenation occurs for 3 min. Drugs including neuromuscular blockers are administered, while the operator ensures the airway remains patent. The ventilator transitions into Pressure Controlled Ventilation once apnoea ensues. Nasal oxygen continues until endotracheal tube is successfully secured.
RESULTS: We describe a case series of the first eight consecutive adult patients on who VAPOX was applied. All eight patients were clinically deemed at high risk of oxygen desaturation. No clinically significant hypoxia occurred, and the lowest oxyhaemoglobin desaturation was 92%.
CONCLUSION: Preoxygenation using a ventilator with an open valve system may allow safe combination of non-invasive ventilation, pressure controlled ventilation and apnoeic oxygenation using nasal cannula. VAPOX may be the technique of choice to preoxygenate and apnoeic oxygenate many patients who undergo rapid sequence intubation in the ED equipped with these ventilators.
The First Shot Is Often the Best Shot: First-Pass Intubation Success in Emergency Airway Management.
Bernhard M, Becker TK, Gries A, Knapp J, Wenzel V. Anesth Analg. 2015 Nov;121(5):1389-93.
Our take-home message is more complex than “every effort should be made to secure the airway on the first, well-prepared intubation attempt”, although the mnemonic “the first shot is often the best shot” is very appealing. First, anticipating severe adverse events if the first intubation attempt fails is an important aspect of a “first-shot best shot” approach. Second, anesthesiology training improves first-pass success rates, although whether such training requires 150 successful intubations as in a German study or 3 years of clinical training as in a UK recommendation is unclear. Third, sufficient optimization of first-pass success rates is difficult to obtain and/or to maintain for many airway managers because of a lack of experience with the procedure. Fourth, there are insufficient data for determining whether more simulation will improve first-pass intubation rates. Finally, when managing an airway, each individual should assess the odds of initial success versus possible problems or complications and build in an appropriate margin for safety.
Jarrod M. Mosier, Raj Joshi, Cameron Hypes, Garrett Pacheco, Terence Valenzuela, John C. Sakles.
Western Journal of Emergency Medicine, December 2015.
Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation.
Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults.
C Frerk, V S Mitchell, A F McNarry, C Mendonca, R Bhagrath, A Patel, E P O'Sullivan, N M Woodall, I Ahmad
British Journal of Anaesthesia 2015, 115 (6): 827-848
These guidelines provide a strategy to manage unanticipated difficulty with tracheal intubation. They are founded on published evidence. Where evidence is lacking, they have been directed by feedback from members of the Difficult Airway Society and based on expert opinion. These guidelines have been informed by advances in the understanding of crisis management; they emphasize the recognition and declaration of difficulty during airway management. A simplified, single algorithm now covers unanticipated difficulties in both routine intubation and rapid sequence induction. Planning for failed intubation should form part of the pre-induction briefing, particularly for urgent surgery. Emphasis is placed on assessment, preparation, positioning, preoxygenation, maintenance of oxygenation, and minimizing trauma from airway interventions. It is recommended that the number of airway interventions are limited, and blind techniques using a bougie or through supraglottic airway devices have been superseded by video- or fibre-optically guided intubation. If tracheal intubation fails, supraglottic airway devices are recommended to provide a route for oxygenation while reviewing how to proceed. Second-generation devices have advantages and are recommended. When both tracheal intubation and supraglottic airway device insertion have failed, waking the patient is the default option. If at this stage, face-mask oxygenation is impossible in the presence of muscle relaxation, cricothyroidotomy should follow immediately. Scalpel cricothyroidotomy is recommended as the preferred rescue technique and should be practised by all anaesthetists. The plans outlined are designed to be simple and easy to follow. They should be regularly rehearsed and made familiar to the whole theatre team.
Is Single-Dose Etomidate Induction Safe in Emergency Intubation of Critically Ill Patients?
Diem Tt Tran, Ethan K Newton, Victoria Ah Mount, Jacques S Lee, George A Wells, Jeffrey J Perry
Cochrane Database of Systematic Reviews 2015 October 29, 10: CD002788
BACKGROUND:Patients requiring emergency endotracheal intubation often require a rapid sequence induction (RSI) intubation technique to protect against aspiration or increased intracranial pressure, or to facilitate intubation. Succinylcholine is the most commonly used muscle relaxant because of its fast onset and short duration; unfortunately, it can have serious side effects. Rocuronium has been suggested as an alternative to succinylcholine for intubation. This meta-analysis is an update since our initial Cochrane systematic review in 2003.\n\nOBJECTIVES:To determine if rocuronium creates comparable intubating conditions to succinylcholine during RSI intubation. Comparisons were made based on dose of rocuronium, narcotic use, emergency versus elective intubation, age and induction agent. The primary outcome was excellent intubation conditions. The secondary outcome was acceptable conditions.\n\nSEARCH STRATEGY:In our initial systematic review we searched all databases until March 2000. We have updated that search and searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2007 issue 3), MEDLINE (1966 to June Week 3 2007), EMBASE (1988 to 2007 Week 26) for randomized controlled trials or controlled clinical trials relating to the use of rocuronium and succinylcholine. We included foreign language journals and handsearched the references of identified studies for additional citations.\n\nSELECTION CRITERIA:We included all trials meeting the inclusion criteria (comparison of rocuronium and succinylcholine, main outcomes of intubation conditions).\n\nDATA COLLECTION AND ANALYSIS:Two authors (JP, JL or VS) independently extracted data and assessed methodological quality for allocation concealment. We combined the outcomes in RevMan using relative risk (RR) with a random-effects model.\n\nMAIN RESULTS:In our initial systematic review we identified 40 studies and included 26. In this update we identified a further 18 studies and included 11. In total, we identified 58 potential studies; 37 were combined for meta-analysis. Overall, succinylcholine was superior to rocuronium, RR 0.86 (95% confidence interval (95% CI) 0.80 to 0.92) (n = 2690). In the group that used propofol for induction, the intubation conditions were superior with succinylcholine (RR 0.88, 95% CI 0.80 to 0.97) (n = 1183). This is contrary to our previous meta-analysis results where we reported that intubation conditions were superior in the rocuronium group when propofol was used. We found no statistical difference in intubation conditions when succinylcholine was compared to 1.2mg/kg rocuronium; however, succinylcholine was clinically superior as it has a shorter duration of action.\n\nAUTHORS' CONCLUSIONS:Succinylcholine created superior intubation conditions to rocuronium when comparing both excellent and clinically acceptable intubating conditions.
The Inaccuracy of Using Landmark Techniques for Cricothyroid Membrane Identification: A Comparison of Three Techniques.
OBJECTIVES Successful cricothyrotomy is predicated on accurate identification of the cricothyroid membrane (CTM) by palpation of superficial anatomy. However, recent research has indicated that accuracy of the identification of the CTM can be as low as 30%, even in the hands of skilled providers. To date, there are very little data to suggest how to best identify this critical landmark. The objective was to compare three different methods of identifying the CTM. METHODS A convenience sample of patients and physician volunteers who met inclusion criteria was consented. The patients were assessed by physician volunteers who were randomized to one of three methods for identifying the CTM (general palpation of landmarks vs. an approximation based on four finger widths vs. an estimation based on overlying skin creases of the neck). Volunteers would then mark the skin with an invisible but florescent pen. A single expert evaluator used ultrasound to identify the superior and inferior borders of the CTM. The variably colored florescent marks were then visualized with ultraviolet light and the accuracy of the various methods was recorded as the primary outcome. Additionally, the time it took to perform each technique was measured. Descriptive statistics and report 95% confidence intervals (CIs) are reported. RESULTS Fifty adult patients were enrolled, 52% were female, and mean body mass index was 28 kg/m(2) (95% CI = 26 to 29 kg/m(2) ). The general palpation method was successful 62% of the time (95% CI = 48% to 76%) and took an average of 14 seconds to perform (range = 5 to 45 seconds). In contrast, the four-finger technique was successful 46% of the time (95% CI = 32% to 60%) and took an average of 12 seconds to perform (range = 6 to 40 seconds). Finally, the neck crease method was successful 50% of the time (95% CI = 36% to 64%) and took an average of 11 seconds to perform (range = 5 to 15 seconds). CONCLUSIONS All three methods performed poorly overall. All three techniques might potentially be even less accurate in instances where the superficial anatomy is not palpable due to body habitus. These findings should alert clinicians to the significant risk of a misplaced cricothyrotomy and highlight the critical need for future research.
David P Thomson, Darren Braude, Kevin High, Rachel Miller-Tester
Air Medical Journal 2015, 34 (2): 113-6
Aviation terminology and thought processes are commonly applied to medicine. We further propose the adaptation of instrument flight terminology to emergency airway management including the aviation approach plate visual aid and replacement of the term "failed airway" with "missed airway,"
More Than One Third of Intubations in Patients Transferred to Burn Centers are Unnecessary/ Proposed Guidelines for Appropriate Intubation of the Burn Patient
Kathleen S Romanowski, Tina L Palmieri, Soman Sen, David G Greenhalgh
Journal of Burn Care & Research: Official Publication of the American Burn Association 2015 August 17
Advanced Burn Life Support emphasizes endotracheal intubation for patients with facial burns before transfer to a burn center to prevent airway obstruction. Many patients are intubated before transport and are often extubated shortly after burn center arrival. We hypothesize that many intubations performed before burn center transport are unnecessary. We conducted a retrospective review of all adults who were intubated before burn transfer and survived to discharge from August 2003 to June 2013. Intubations that had 2 or fewer ventilator days (i.e., potentially unnecessary intubations) were compared with those lasting longer than 2 days. Data collected included age, ventilator days, length of stay, % TBSA burn, % second degree, % third degree, % second degree face burn, % third degree face burn, and origin of burns. A total of 416 patient met inclusion criteria. Of these, 129 patients (31.0%) were intubated less than or equal to 1 day, and a total of 171 (40.1%) patients remained intubated for less than or equal to 2 days. Patients who were intubated less than or equal to 2 days differed from those intubated more than 2 days with respect to % TBSA burn (10.2 ± 8.1 vs 30.8 ± 19.7, P < .001), % third degree burn (2.84 ± 5.6 vs 22.5 ± 19.6, P < .001), % third degree face burn (0.14 ± 0.7 vs 0.94 ± 1.9, P < .001), and hospital days (11.7 ± 10.6 vs 50.7 ± 43.7, P < .001). Additionally, patients who were intubated less than or equal to 2 days were more likely to have been intubated in the pre-burn center setting (74.9% vs 51.8%, P < .001) and to have been burned outdoors (42.1% vs 24.9%; P < .001) than those who were intubated more than 2 days. Multivariate analysis revealed that intubation longer than 2 days was independently associated with older age and larger % TBSA burn. There were no reintubations in patients who were intubated 2 days or less. As a burn community, we have emphasized early intubation before transfer for those who have sustained significant burns, inhalational injury, or facial burns. Unfortunately, this has led to many potentially unnecessary intubations that expose patients to unnecessary complications. Although early intubation is a lifesaving intervention for many burn patients, criteria should be developed to determine when intubation is not needed.
Should anesthesiologists have to confirm effective facemask ventilation before administering the muscle relaxant?
Journal of Anesthesia 2015 September 3
There is ongoing controversy as to whether effective facemask ventilation (FMV) should be established following induction of anesthesia before a muscle relaxant is administered. The rationale for such practice is the belief that, should FMV be ineffective, non-paralyzed patients can be woken up, and subsequently an alternative airway management can be considered. However, the chances of successfully restoring adequate spontaneous respiration before severe hypoxemia develops in an anesthetized, apneic patient who is prone to anesthetic-induced respiratory depression and airway collapse are very small. On the other hand, the overall evidence shows that muscle relaxation is likely to improve or leave unchanged, but not to worsen, the quality of FMV. Furthermore, muscle relaxation will facilitate placement of a supraglottic airway device and endotracheal intubation, interventions which may become essential should the patient become hypoxemic during failed FMV. Thus, the earliest administration of a muscle relaxant following induction of anesthesia may well be the most effective and safest practice. Insistence on demonstration of adequate FMV before administration of a muscle relaxant is more of a ritual than an evidence-based practice. It should therefore be abandoned.
Establishing a definitive airway in the trauma patient by novice intubators: A randomised crossover simulation study
Itai Shavit, Barak Levit, Nofar Ben Basat, Dekel Lait, Mostafa Somri, Luis Gaitini
Injury 2015 August 31
BACKGROUND: Establishing a definitive airway, defined as a tube placed in the trachea with cuff inflated below the vocal cords, is standard of care in pre-hospital airway management of the trauma patient. However, in this setting, and using manual in-line stabilisation of the neck, success rate of intubation by inexperience providers is suboptimal. The use of supraglottic airway devices that allow blind tracheal intubation has been suggested as an alternative method by the Advanced Trauma Life Support (ATLS) programme of the American College of Surgeons. We aimed to compare intubation with the standard intubation technique (direct laryngoscopy [DL]) with blind intubation through an intubating-laryngeal mask airway (I-LMA) during manual in-line stabilisation of the neck.
MATERIALS AND METHODS: A randomised, crossover manikin study was performed with 29 emergency medical technicians undergoing training for paramedic status. Outcome measures were success rate in one intubation attempt, duration of intubation, and assessment of ease-of-use.
RESULTS: Study subjects had a higher success rate of tracheal intubation with I-LMA than with DL (27/29 vs. 18/29, p<0.025), and I-LMA was assessed as easier to use (4 vs. 3, p<0.0001). Longer duration of intubation was found with I-LMA compared to DL (54.2 vs. 42.8s, p<0.002). Success rate of correct placement of I-LMA within the airway was 28/29 (96.5%). Time to achieve correct placement of I-LMA within the airway was shorter than duration of tracheal intubation with DL (26.9 vs. 42.8s, p<0.0001).
CONCLUSIONS: Novice intubators had a higher success rate of intubation with I-LMA than with DL, but duration of intubation was longer with I-LMA. Time to achieve correct placement of I-LMA within the airway was shorter than duration of tracheal intubation with DL. Findings of this simulation study suggest that in the presence of manual in-line stabilisation of the neck, I-LMA-guided intubation is the preferred technique for novice intubators.
Risk Factors for Failed Tracheal Intubation in Pediatric and Neonatal Critical Care Specialty Transport
Kristen A Smith, M David Gothard, Hamilton P Schwartz, John S Giuliano, Michael Forbes, Michael T Bigham
Prehospital Emergency Care 2015, 19 (1): 17-22
Abstract Objective. Nearly 200,000 pediatric and neonatal transports occur in the United States each year with some patients requiring tracheal intubation. First-pass intubation rates in both pediatric and adult transport literature are variable as are the factors that influence intubation success. This study sought to determine risk factors for failed tracheal intubation in neonatal and pediatric transport. Methods. A retrospective chart review was performed over a 2.5-year period. Data were collected from a hospital-based neonatal/pediatric critical care transport team that transports 2,500 patients annually, serving 12,000 square miles. Patients were eligible if they were transported and tracheally intubated by the critical care transport team. Patients were categorized into two groups for data analysis: (1) no failed intubation attempts and (2) at least one failed intubation attempt. Data were tabulated using Epi Info Version 3.5.1 and analyzed using SPSSv17.0. Results. A total of 167 patients were eligible for enrollment and were cohorted by age (48% pediatric versus 52% neonatal). Neonates were more likely to require multiple attempts at intubation when compared to the pediatric population (69.6% versus 30.4%, p = 0.001). Use of benzodiazepines and neuromuscular blockade was associated with increased successful first attempt intubation rates (p = 0.001 and 0.008, respectively). Use of opiate premedication was not associated with first-attempt intubation success. The presence of comorbid condition(s) was associated with at least one failed intubation attempt (p = 0.006). Factors identified with increasing odds of at least one intubation failure included, neonatal patients (OR 3.01), tracheal tube size ≤ 2.5 mm (OR 3.78), use of an uncuffed tracheal tube (OR 6.85), and the presence of a comorbid conditions (OR 2.64). Conclusions. There were higher rates of tracheal intubation failure in transported neonates when compared to pediatric patients. This risk may be related to the lack of benzodiazepine and neuromuscular blocking agents used to facilitate intubation. The presence of a comorbid condition is associated with a higher risk of tracheal intubation failure.
Incidence and Duration of Continuously Measured Oxygen Desaturation During Emergency Department Intubation
Jerry B Bodily, Heather R Webb, Steve J Weiss, Darren A Braude
Annals of Emergency Medicine 2015 July 9
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STUDY OBJECTIVE: Desaturation during intubation has been associated with serious complications, including dysrhythmias, hemodynamic decompensation, hypoxic brain injury, and cardiac arrest. We seek to determine the incidence and duration of oxygen desaturation during emergency department (ED) rapid sequence intubation.
METHODS: This study included adult rapid sequence intubation cases conducted between September 2011 and July 2012 in an urban, academic, Level I trauma center ED. We obtained continuous vital signs with BedMasterEX data acquisition software. Start and completion times of rapid sequence intubation originated from nursing records. We defined oxygen desaturation as (1) cases exhibiting SpO2 reduction to less than 90% if the starting SpO2 was greater than or equal to 90%, or (2) a further reduction in SpO2 in cases in which starting SpO2 was less than 90%. We used multivariable logistic regression to predict oxygen desaturation during rapid sequence intubation.
RESULTS: During the study period, there were 265 rapid sequence intubation cases. The study excluded 99 cases for failure of electronic data acquisition, inadequate documentation, or poor SpO2 waveform during rapid sequence intubation, and excluded cases managed by anesthesia providers, leaving 166 patients in the analysis. After preoxygenation, starting SpO2 was greater than 93% in 124 of 166 cases (75%) and SpO2 was less than 93% in the remaining 46 cases. Oxygen desaturation occurred in 59 patients (35.5%). The median duration of desaturation was 80 seconds (interquartile range 40, 155). Multivariable analysis demonstrated that oxygen desaturation was associated with preintubation SpO2 less than 93% (odds ratio [OR] 5.1; 95% confidence interval (CI) 2.3 to 11.0), multiple intubation attempts (>1 attempt) (OR 3.4; 95% CI 1.4 to 6.1), and rapid sequence intubation duration greater than 3 minutes (OR 2.7; 95% CI 1.2 to 6.1).
CONCLUSION: In this series, 1 in 3 patients undergoing ED rapid sequence intubation experienced oxygen desaturation for a median duration of 80 seconds. Preintubation saturation less than 93%, multiple intubation attempts, and prolonged intubation time are independently associated with oxygen desaturation. Clinicians should use strategies to prevent oxygen desaturation during ED rapid sequence intubation.
A Preprocedural Checklist Improves the Safety of Emergency Department Intubation of Trauma Patients
Kurt A Smith, Kevin High, Sean P Collins, Wesley H Self
Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine 2015 July 20
OBJECTIVES: Endotracheal intubation of trauma patients is a vital and high-risk procedure in the emergency department (ED). The hypothesis was that implementation of a standardized, preprocedural checklist would improve the safety of this procedure.
METHODS: A preprocedural intubation checklist was developed and then implemented in a prospective pre-/postinterventional study in an academic trauma center ED. The proportions of trauma patients older than 16 years who experienced intubation-related complications during the 6 months before checklist implementation and 6 months after implementation were compared. Intubation-related complications included oxygen desaturation, emesis, esophageal intubation, hypotension, and cardiac arrest. Additional outcomes included time from paralysis to intubation and adherence to safety process measures.
RESULTS: During the study, 141 trauma patients were intubated, including 76 in the prechecklist period and 65 in the postchecklist period. A lower proportion of patients experienced intubation-related complications in the postchecklist period (1.5%) than the prechecklist period (9.2%), representing a 7.7% (95% confidence interval = 0.5% to 14.8%) absolute risk reduction. Paralysis-to-intubation time was also lower in the postchecklist period (median = 82 seconds, interquartile range [IQR] = 68 to 101 seconds) compared to the prechecklist period (median = 94 seconds, IQR = 78 to 115 seconds; p = 0.02). Adherence to safety process measures also improved, with all safety measures performed in 69.2% in the postchecklist period compared to 17.1% before the checklist (p < 0.01).
CONCLUSIONS: Implementation of a preintubation checklist for ED intubation of trauma patients was associated with a reduction in intubation-related complications, decreased paralysis-to-intubation time, and improved adherence to recognized safety measures.
Incidence of and risk factors for severe cardiovascular collapse after endotracheal intubation in the ICU: a multicenter observational study
Sebastien Perbet, Audrey De Jong, Julie Delmas, Emmanuel Futier, Bruno Pereira, Samir Jaber, Jean-Michel Constantin
Critical Care: the Official Journal of the Critical Care Forum 2015, 19: 257
INTRODUCTION: Severe cardiovascular collapse (CVC) is a life-threatening complication after emergency endotracheal intubation (ETI) in the ICU. Many factors may interact with hemodynamic conditions during ETI, but no study to date has focused on factors associated with severe CVC occurrence. This study assessed the incidence of severe CVC after ETI in the ICU and analyzed the factors predictive of severe CVC.
METHODS: This was a secondary analysis of a prospective multicenter study of 1,400 consecutive intubations at 42 ICUs. The incidence of severe CVC was assessed in patients who were hemodynamically stable (mean arterial blood pressure >65 mmHg without vasoactive drugs) before intubation, and the factors predictive of severe CVC were determined by multivariate analysis based on patient and procedure characteristics.
RESULTS: Severe CVC occurred following 264 of 885 (29.8 %) intubation procedures. A two-step multivariate analysis showed that independent risk factors for CVC included simple acute physiologic score II regardless of age (odds ratio (OR) 1.02, p < 0.001), age 60-75 years (OR 1.96, p < 0.002 versus <60 years) and >75 years (OR 2.81, p < 0.001 versus <60 years), acute respiratory failure as a reason for intubation (OR 1.51, p = 0.04), first intubation in the ICU (OR 1.61, p = 0.02), noninvasive ventilation as a preoxygenation method (OR 1.54, p = 0.03) and inspired oxygen concentration >70 % after intubation (OR 1.91, p = 0.001). Comatose patients who required ETI were less likely to develop CVC during intubation (OR 0.48, p = 0.004).
CONCLUSIONS: CVC is a frequent complication, especially in old and severely ill patients intubated for acute respiratory failure in the ICU. Specific bundles to prevent CVC may reduce morbidity and mortality related to intubation of these high-risk, critically ill patients.
Journal of Intensive Care 2015, 3 (1): 15
High-flow nasal cannula (HFNC) oxygen therapy comprises an air/oxygen blender, an active humidifier, a single heated circuit, and a nasal cannula. It delivers adequately heated and humidified medical gas at up to 60 L/min of flow and is considered to have a number of physiological effects: reduction of anatomical dead space, PEEP effect, constant fraction of inspired oxygen, and good humidification. While there have been no big randomized clinical trials, it has been gaining attention as an innovative respiratory support for critically ill patients. Most of the available data has been published in the neonatal field. Evidence with critically ill adults are poor; however, physicians apply it to a variety of patients with diverse underlying diseases: hypoxemic respiratory failure, acute exacerbation of chronic obstructive pulmonary disease, post-extubation, pre-intubation oxygenation, sleep apnea, acute heart failure, patients with do-not-intubate order, and so on. Many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces needs of escalation of respiratory support in patients with diverse underlying diseases. Some important issues remain to be resolved, such as its indication, timing of starting and stopping HFNC, and escalating treatment. Despite these issues, HFNC oxygen therapy is an innovative and effective modality for the early treatment of adults with respiratory failure with diverse underlying diseases.
D John Doyle
Anesthesiology Clinics 2015, 33 (2): 291-304
Topical anesthesia of the airway is a necessary for awake intubation and is usually achieved using lidocaine delivered by various means. Although some experts favor the use of airway blocks, a more common approach is to use pure topical methods in combination with "spray as you go" techniques. Once the topicalization is complete, the patient should be able to easily tolerate the use of an oral airway used to facilitate awake oral intubation. Nasal intubation requires additional topicalization of the nasal passages in conjunction with a vasoconstrictor. Finally, judicious sedation is frequently used when awake intubation is carried out.
GlideScope video laryngoscopy versus direct laryngoscopy in the emergency department: a propensity score-matched analysis
Hyuk Joong Choi, Young-Min Kim, Young Min Oh, Hyung Goo Kang, Hyun Woo Yim, Seung Hee Jeong
BMJ Open 2015, 5 (5): e007884
OBJECTIVE: To evaluate whether the use of a GlideScope video laryngoscope (GVL) improves first-attempt intubation success compared with the Macintosh laryngoscope (MAC) in the emergency department (ED).
DESIGN: A propensity score-matched analysis of data from a prospective multicentre ED airway registry-the Korean Emergency Airway Management Registry (KEAMR).
SETTING: 4 academic EDs located in a metropolitan city and a province in South Korea.
PARTICIPANTS: A total of 4041 adult patients without cardiac arrest who underwent emergency intubation from January 2007 to December 2010.
OUTCOME MEASURES: The primary and secondary outcomes were successful first intubation attempt and intubation failure, respectively. To reduce the selection bias and potential confounding effects, we rigorously adjusted for the baseline differences between two groups using a propensity score matching.
RESULTS: Of the 4041 eligible patients, a GVL was initially used in 540 patients (13.4%). Using 1:2 propensity score matching, 363 and 726 patients were assigned to the GVL and MAC groups, respectively. The adjusted relative risks (95% CIs) for the first-attempt success rates with a GVL compared with a MAC were 0.76 (0.56 to 1.04; p=0.084) and the respective intubation failure rates 1.03(0.99 to 1.07; p=0.157). Regarding the subgroups, the first-attempt success of the senior residents and attending physicians was lower with the GVL (0.47 (0.23 to 0.98), p=0.043). In the patients with slight intubation difficulty, the first-attempt success was lower (0.60 (0.41 to 0.88), p=0.008) and the intubation failure was higher with the GVL (1.07 (1.02 to 1.13), p=0.008).
CONCLUSIONS: In this propensity score-matched analysis of data from a prospective multicentre ED airway registry, the overall first-attempt intubation success and failure rates did not differ significantly between GVL and MAC in the ED setting. Further randomised controlled trials are needed to confirm our findings.
Justin L Benoit, David K Prince, Henry E Wang
Resuscitation 2015, 93: 124-7
Advanced airway management - such as endotracheal intubation (ETI) or supraglottic airway (SGA) insertion - is one of the most prominent interventions in out-of-hospital cardiac arrest (OHCA) resuscitation. While randomized controlled trials are currently in progress to identify the best advanced airway technique in OHCA, the mechanisms by which airway management may influence OHCA outcomes remain unknown. We provide a conceptual model describing potential mechanisms linking advanced airway management with OHCA outcomes.
Emergent Awake tracheostomy-The five-year experience at an urban tertiary care center
Christina H Fang, Remy Friedman, Priscilla E White, Leila J Mady, Evelyne Kalyoussef
Laryngoscope 2015 June 24
OBJECTIVES/HYPOTHESIS: There are few studies that discuss the issues surrounding emergent awake tracheostomy. We aim to review the indications, anesthesia used, complications, and outcomes of patients undergoing urgent awake tracheostomy.
STUDY DESIGN: Chart review.
METHODS: Medical charts of patients who underwent an emergent awake tracheostomy at our institution-affiliated tertiary care center over a 5-year period from 2009 to 2014 were reviewed. Data were collected from inpatient, outpatient, and operative records.
RESULTS: Sixty-eight patients underwent emergent awake tracheostomy. Over half presented with hoarseness (n = 37, 54.4%) and/or stridor (n = 37, 54.4%). Acute upper airway obstruction secondary to malignancy was the most common indication and accounted for 58 cases (85.3%). Thirty-nine (70.1%) of the 55 patients with squamous cell carcinoma presented with advanced disease (stage III or IV). Other indications included glottic or subglottic stenosis (4.4%), failure to intubate (2.9%), and other (7.4%). Local anesthesia was used alone in 35.3% of cases and in combination with conscious sedation in 64.7% of cases. Mild bleeding occurred postoperatively in five patients (7.4%). There were no other postoperative complications. Nineteen patients were lost to follow-up. The mean follow-up of 49 patients was 7.2 weeks, ranging from 2 to 261 weeks. Long-term complications occurred in three patients and included tracheitis 7.4% and suprastomal granuloma 2.9%. Eleven patients (22%) were decannulated at a mean of 11.8 months following tracheostomy.
CONCLUSIONS: Emergent awake tracheostomy should be considered in patients with impeding airway obstruction and is a safe and effective method to secure an airway in these patients.
LEVEL OF EVIDENCE: 4 Laryngoscope, 2015.
Postintubation hypotension in intensive care unit patients: A multicenter cohort study
Robert S Green, Alexis F Turgeon, Lauralyn A McIntyre, Alison E Fox-Robichaud, Dean A Fergusson, Steve Doucette, Michael B Butler, Mete Erdogan. Journal of Critical Care 2015 June 16
PURPOSE: To determine the incidence of postintubation hypotension (PIH) and associated outcomes in critically ill patients requiring endotracheal intubation.
MATERIALS AND METHODS: Medical records were reviewed for 479 consecutive critically ill adult patients who required intubation by an intensive care unit (ICU) service at 1 of 4 academic tertiary care hospitals. The primary outcome measure was the incidence of PIH. Secondary outcome measures included mortality, ICU length of stay, requirement for renal replacement therapy, and a composite end point consisting of overall mortality, ICU length of stay greater than 14 days, duration of mechanical ventilation longer than 7 days, and renal replacement therapy requirement.
RESULTS: Overall, the incidence of PIH among ICU patients requiring intubation was 46% (218/479 patients). On univariate analysis, patients who developed PIH had increased ICU mortality (37% PIH vs 28% no PIH, P = .049) and overall mortality (39% PIH vs 30% no PIH, P = .045). After adjusting for important risk factors, development of PIH was associated with the composite end point of major morbidity and mortality (odds ratio, 2.00; 95% confidence interval, 1.30-3.07; P = .0017).
CONCLUSIONS: The development of PIH is common in ICU patients requiring emergency airway control and is associated with poor patient outcomes.
Ventilator Strategies and Rescue Therapies for Management of Acute Respiratory Failure in the Emergency Department
Jarrod M Mosier, Cameron Hypes, Raj Joshi, Sage Whitmore, Sairam Parthasarathy, Charles B Cairns
Annals of Emergency Medicine 2015 May 23
Acute respiratory failure is commonly encountered in the emergency department (ED), and early treatment can have effects on long-term outcome. Noninvasive ventilation is commonly used for patients with respiratory failure and has been demonstrated to improve outcomes in acute exacerbations of chronic obstructive lung disease and congestive heart failure, but should be used carefully, if at all, in the management of asthma, pneumonia, and acute respiratory distress syndrome. Lung-protective tidal volumes should be used for all patients receiving mechanical ventilation, and FiO2 should be reduced after intubation to achieve a goal of less than 60%. For refractory hypoxemia, new rescue therapies have emerged to help improve the oxygenation, and in some cases mortality, and should be considered in ED patients when necessary, as deferring until ICU admission may be deleterious. This review article summarizes the pathophysiology of acute respiratory failure, management options, and rescue therapies including airway pressure release ventilation, continuous neuromuscular blockade, inhaled nitric oxide, and extracorporeal membrane oxygenation.
Tips and Troubleshooting for Use of the GlideScope Video Laryngoscope for Emergency Endotracheal Intubation
Emily R Bacon, Michael P Phelan, D John Doyle
American Journal of Emergency Medicine 2015 May 13
Video laryngoscopy (VL) is still a relatively novel advancement in airway management that offers many potential benefits over direct laryngoscopy. These advantages include decreased time to intubation in difficulty airways, unique opportunities in teaching as the video screen allows for real time teaching points, increased first pass success, particularly with novice operators, and decreased cervical spine motion during intubation. Despite the advantages, the intubation procedure itself has some subtle but significant differences from direct laryngoscopy that change the expected motion as well as troubleshooting techniques, which might discourage the use of the GlideScope by practitioners less familiar with the product. With the hope of generating confidence in the video laryngoscopy procedure, we have compiled some basic tips that we have found helpful when intubating with the GlideScope. These tips include inserting the blade to the left of midline to improve space allowed for the endotracheal tube itself, backing the scope up a small amount to improve the view, holding the tube close to the connector to improve maneuverability, and withdrawing the tube with your thumb to improve advancement through the cords. We hope that, with these tips, in conjunction with ample practice, clinicians can gain comfort and experience with all the tools at our disposal in an effort to provide the best possible care for our patients.
A radiographic comparison of human airway anatomy and airway manikins - Implications for manikin-based testing of artificial airways
Richard Schalk, Kathrin Eichler, Martin N Bergold, Christian F Weber, Kai Zacharowski, Dirk Meininger, Christian Byhahn, Haitham Mutlak
Resuscitation 2015 May 11
OBJECTIVE: The aim of this prospective, single-center, observational study was to investigate the accuracy of modeling and reproduction of human anatomical dimensions in manikins by comparing radiographic upper airway measurements of 13 different models with humans.
METHODS: 13 commonly used airway manikins (male or female anatomy based) and 47 controls (adult humans, 37 male, 10 female) were investigated using a mediosagittal and axial cervical spine CT scan. For anatomical comparison six human upper airway target structures, the following were measured: Oblique diameter of the tongue through the center, horizontal distance between the center point of the tongue and the posterior pharyngeal wall, horizontal distance between the vallecula and the posterior pharyngeal wall, distance of the upper oesophageal orifice length of epiglottis distance at the narrowest part of the trachea. Furthermore, the cross-section of the trachea in axial view and the cross-section of the upper oesophageal orifice in the same section was calculated. All measurements were compared gender specific, if the gender was non-specified with the whole sample.
RESULTS: None of the included 13 different airway manikins matched anatomy in human controls (n=47) in all of the six measurements. The Laerdal Airway Management Trainer, however, replicated human airway anatomy at least satisfactorily.
CONCLUSION: This investigation showed that all of the examined manikins did not replicate human anatomy. Manikins should therefore be selected cautiously, depending on the type of airway securing procedure. Their widespread use as a replacement for in vivo trials in the field of airway management needs to be reconsidered.
High-Flow Oxygen through Nasal Cannula in Acute Hypoxemic Respiratory Failure
Jean-Pierre Frat, Arnaud W Thille, Alain Mercat et al. New England Journal of Medicine 2015 May 17
Background Whether noninvasive ventilation should be administered in patients with acute hypoxemic respiratory failure is debated. Therapy with high-flow oxygen through a nasal cannula may offer an alternative in patients with hypoxemia. Methods We performed a multicenter, open-label trial in which we randomly assigned patients without hypercapnia who had acute hypoxemic respiratory failure and a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen of 300 mm Hg or less to high-flow oxygen therapy, standard oxygen therapy delivered through a face mask, or noninvasive positive-pressure ventilation. The primary outcome was the proportion of patients intubated at day 28; secondary outcomes included all-cause mortality in the intensive care unit and at 90 days and the number of ventilator-free days at day 28. Results A total of 310 patients were included in the analyses. The intubation rate (primary outcome) was 38% (40 of 106 patients) in the high-flow-oxygen group, 47% (44 of 94) in the standard group, and 50% (55 of 110) in the noninvasive-ventilation group (P=0.18 for all comparisons). The number of ventilator-free days at day 28 was significantly higher in the high-flow-oxygen group (24±8 days, vs. 22±10 in the standard-oxygen group and 19±12 in the noninvasive-ventilation group; P=0.02 for all comparisons). The hazard ratio for death at 90 days was 2.01 (95% confidence interval [CI], 1.01 to 3.99) with standard oxygen versus high-flow oxygen (P=0.046) and 2.50 (95% CI, 1.31 to 4.78) with noninvasive ventilation versus high-flow oxygen (P=0.006). Conclusions In patients with nonhypercapnic acute hypoxemic respiratory failure, treatment with high-flow oxygen, standard oxygen, or noninvasive ventilation did not result in significantly different intubation rates. There was a significant difference in favor of high-flow oxygen in 90-day mortality.
Facemask ventilation during induction of anesthesia: how "gentle" is "gentle" enough?
DURING anesthesia induction, even skilled anesthesiologists may sometimes have the impression that they just have insufflated gas in the patient’s stomach during manual facemask ventilation. To avoid the consequences of such a gastric inflation in patients at risk of aspiration, most of us were taught not to conduct facemask ventilation before intubation—even though this strategy may need to be revisited when severe hypoxemia develops or is expected. “Gentle” facemask ventilation hasbeen recommended—but what does that mean?
High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomized controlled clinical trial
Mickaël Vourc'h, Pierre Asfar, Christelle Volteau, Konstantinos Bachoumas, Noëmie Clavieras, Pierre-Yves Egreteau, Karim Asehnoune, Alain Mercat, Jean Reignier, Samir Jaber, Gwenaël Prat, Antoine Roquilly, Noëlle Brule, Daniel Villers, Cédric Bretonniere, Christophe Guitton
Intensive Care Medicine 2015 April 14
PURPOSE: Intubation of hypoxemic patients is associated with life-threatening adverse events. High-flow therapy by nasal cannula (HFNC) for preoxygenation before intubation has never been assessed by randomized study. Our objective was to evaluate the efficiency of HFNC for preoxygenation, compared to high fraction-inspired oxygen facial mask (HFFM).
METHODS: Multicenter, randomized, open-labelled, controlled PREOXYFLOW trial (NCT 01747109) in six French intensive care units. Acute hypoxemic adults requiring intubation were randomly allocated to HFNC or HFFM. Patients were eligible if PaO2/FiO2 ratio was below 300 mmHg, respiratory rate at least 30/min and if they required FiO2 50 % or more to obtain at least 90 % oxygen saturation. HFNC was maintained throughout the procedure, whereas HFFM was removed at the end of general anaesthesia induction. Primary outcome was the lowest saturation throughout intubation procedure. Secondary outcomes included adverse events related to intubation, duration of mechanical ventilation and death.
RESULTS: A total of 124 patients were randomized. In the intent-to-treat analysis, including 119 patients (HFNC n = 62; HFFM n = 57), the median (interquartile range) lowest saturation was 91.5 % (80-96) for HFNC and 89.5 % (81-95) for the HFFM group (p = 0.44). There was no difference for difficult intubation (p = 0.18), intubation difficulty scale, ventilation-free days (p = 0.09), intubation-related adverse events including desaturation <80 % or mortality (p = 0.46).
CONCLUSIONS: Compared to HFFM, HFNC as a preoxygenation device did not reduce the lowest level of desaturation.
Prehospital endotracheal intubation: elemental or detrimental?
Paul E Pepe, Lynn P Roppolo, Raymond L Fowler
Critical Care: the Official Journal of the Critical Care Forum 2015, 19 (1): 121
"...Despite intuitive biases and impressive inferential studies indicating the positive effects of prehospital ETI in certain settings, another evolving body of studies and experiences has unveiled a detrimental effect of prehospital ETI or, at least, no significant advantage to providing the procedure [17,20,22-29]."
From darkness into light': time to make awake intubation with videolaryngoscopy the primary technique for an anticipated difficult airway?
Calvin A Brown, Daniel J Pallin, Ron M Walls
Critical Care Medicine 2015, 43 (3): 717-8
Initially, video laryngoscopes were thought of as “difficult airway” devices. Although this certainly is true, limiting their use only to intubations predicted to be difficult or proven difficult following failed DL attempts, misses the point. Nothing can ever guarantee intubation success; however, it is important to take all necessary steps to maximize first-attempt success. One key such step is selecting the best tool for the job. The study by Silverberg et al (4) adds to the growing body of literature supporting the notion that video laryngoscopes are first-line devices for emergent or urgent airways, regardless of anticipated difficulty. Institutions developing response teams for inpatient airway emergencies should employ a strategy of robust training, which must include difficult airway assessment, the appropriate use of neuromuscular blockade as part of a RSI algorithm,and use of a video laryngoscope as the principal intubation device.
Is it time to retire the DL as a first-line device? In a word, yes.
Development of a guideline for the management of the unanticipated difficult airway in pediatric practice
Ann E Black, Paul E R Flynn, Helen L Smith, Mark L Thomas, Kathy A Wilkinson
Paediatric Anaesthesia 2015 February 16
BACKGROUND: Most airway problems in children are identified in advance; however, unanticipated difficulties can arise and may result in serious complications. Training for these sporadic events can be difficult. We identified the need for a structured guideline to improve clinical decision making in the acute situation and also to provide a guide for teaching.
OBJECTIVE: Guidelines for airway management in adults are widely used; however, none have been previously devised for national use in children. We aimed to develop guidelines for the management of the unanticipated difficult pediatric airway for use by anesthetists working in the nonspecialist pediatric setting.
METHOD: We reviewed available guidelines used in individual hospitals. We also reviewed research into airway management in children and graded papers for the level of evidence according to agreed criteria. A Delphi panel comprising 27 independent consultant anesthetists considered the steps of the acute airway management guidelines to reach consensus on the best interventions to use and the order in which to use them. If following the literature review and Delphi feedback, there was insufficient evidence or lack of consensus, regarding inclusion of a particular point; this was reviewed by a Second Specialist Group comprising 10 pediatric anesthetists.
RESULTS: Using the Delphi group's deliberations and feedback from the Second Specialist Group, we developed three guidelines for the acute airway management of children aged 1-8 years.
CONCLUSIONS: This paper provides the background, available evidence base, and justification for each step in the resultant guidelines and gives a rationale for their use.
Failure of high-flow nasal cannula therapy may delay intubation and increase mortality
Byung Ju Kang, Younsuck Koh, Chae-Man Lim, Jin Won Huh, Seunghee Baek, Myongja Han, Hyun-Suk Seo, Hee Jung Suh, Ga Jin Seo, Eun Young Kim, Sang-Bum Hong
Intensive Care Medicine 2015 February 18
PURPOSE: Intubation in patients with respiratory failure can be avoided by high-flow nasal cannula (HFNC) use. However, it is unclear whether waiting until HFNC fails, which would delay intubation, has adverse effects. The present retrospective observational study assessed overall ICU mortality and other hospital outcomes of patients who received HFNC therapy that failed.
METHODS: All consecutive patients in one tertiary hospital who received HFNC therapy that failed and who then required intubation between January 2013 and March 2014 were enrolled and classified according to whether intubation started early (within 48 h) or late (at least 48 h) after commencing HFNC.
RESULTS: Of the 175 enrolled patients, 130 (74.3 %) and 45 (25.7 %) were intubated before and after 48 h of HFNC, respectively. The groups were similar in terms of most baseline characteristics. The early intubated patients had better overall ICU mortality (39.2 vs. 66.7 %; P = 0.001) than late intubated patients. A similar pattern was seen with extubation success (37.7 vs. 15.6 %; P = 0.006), ventilator weaning (55.4 vs. 28.9 %; P = 0.002), and ventilator-free days (8.6 ± 10.1 vs. 3.6 ± 7.5; P = 0.011). In propensity-adjusted and -matched analysis, early intubation was also associated with better overall ICU mortality [adjusted odds ratio (OR) = 0.317, P = 0.005; matched OR = 0.369, P = 0.046].
CONCLUSIONS: Failure of HFNC might cause delayed intubation and worse clinical outcomes in patients with respiratory failure. Large prospective and randomized controlled studies on HFNC failure are needed to draw a definitive conclusion.
Neurological deterioration during intubation in cervical spine disorders
Neurological deterioration during intubation in cervical spine disorders
Padmaja Durga, Barada Prasad Sahu
Indian Journal of Anaesthesia 2014, 58 (6): 684-92
Anaesthesiologists are often involved in the management of patients with cervical spine disorders. Airway management is often implicated in the deterioration of spinal cord function. Most evidence on neurological deterioration resulting from intubation is from case reports which suggest only association, but not causation. Most anaesthesiologists and surgeons probably believe that the risk of spinal cord injury (SCI) during intubation is largely due to mechanical compression produced by movement of the cervical spine. But it is questionable that the small and brief deformations produced during intubation can produce SCI. Difficult intubation, more frequently encountered in patients with cervical spine disorders, is likely to produce greater movement of spine. Several alternative intubation techniques are shown to improve ease and success, and reduce cervical spine movement but their role in limiting SCI is not studied. The current opinion is that most neurological injuries during anaesthesia are the result of prolonged deformation, impaired perfusion of the cord, or both. To prevent further neurological injury to the spinal cord and preserve spinal cord function, minimizing movement during intubation and positioning for surgery are essential. The features that diagnose laryngoscopy induced SCI are myelopathy present on recovery, short period of unconsciousness, autonomic disturbances following laryngoscopy, cranio-cervical junction disease or gross instability below C3. It is difficult to accept or refute the claim that neurological deterioration was induced by intubation. Hence, a record of adequate care at laryngoscopy and also perioperative period are important in the event of later medico-legal proceedings.
Tracheal intubation in an urban emergency department in Scotland: A prospective, observational study of 3738 intubations
Dean Kerslake, Angela J Oglesby, Nicola Di Rollo, Ed James, Dermot W McKeown, David C Ray
Resuscitation 2015 January 19
Aim: The emergency department (ED) is an area where major airway difficulties can occur, often as complications of rapid sequence induction (RSI). We undertook a prospective, observational study of tracheal intubation performed in a large, urban UK ED to study this further.
Methods: We reviewed data on every intubation attempt made in our ED between January 1999 and December 2011. We recorded techniques and drugs used, intubator details, success rate, and asso- ciated complications. Tracheal intubation in our ED is managed jointly by emergency physicians and anaesthetists; an anaesthetist is contacted to attend to support ED staff when RSI is being performed. Results: We included 3738 intubations in analysis. 2749 (74%) were RSIs, 361 (10%) were other drug combinations, and 628 (17%) received no drugs. Emergency physicians performed 78% and anaesthetists 22% of intubations. Tracheal intubation was successful in 3724 patients (99.6%). First time success rate was 85%; 98% of patients were successfully intubated with two or fewer attempts, and three patients (0.1%) had more than three attempts. Intubation failed in 14 patients; five (0.13%) had a surgical airway performed. Associated complications occurred in 286 (8%) patients. The incidence of complications was associated with the number of attempts made; 7% in one attempt, 15% in two attempts, and 32% in three attempts (p< 0.001).
Conclusion: A collaborative approach between emergency physicians and anaesthetists contributed to a high rate of successful intubation and a low rate of complications. Close collaboration in training and delivery of service models is essential to maintain these high standards and achieve further improvement where possible.
Single induction dose of etomidate versus other induction agents for endotracheal intubation in critically ill patients
Eric A Bruder, Ian M Ball, Stacy Ridi, William Pickett, Corinne Hohl
Cochrane Database of Systematic Reviews 2015 January 8, 1: CD010225
BACKGROUND: The use of etomidate for emergency airway interventions in critically ill patients is very common. In one large registry trial, etomidate was the most commonly used agent for this indication. Etomidate is known to suppress adrenal gland function, but it remains unclear whether or not this adrenal gland dysfunction affects mortality.
OBJECTIVES: The primary objective was to assess, in populations of critically ill patients, whether a single induction dose of etomidate for emergency airway intervention affects mortality.The secondary objectives were to address, in populations of critically ill patients, whether a single induction dose of etomidate for emergency airway intervention affects adrenal gland function, organ dysfunction, or health services utilization (as measured by intensive care unit (ICU) length of stay (LOS), duration of mechanical ventilation, or vasopressor requirements).We repeated analyses within subgroups defined by the aetiologies of critical illness, timing of adrenal gland function measurement, and the type of comparator drug used.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; CINAHL; EMBASE; LILACS; International Pharmaceutical Abstracts; Web of Science; the Database of Abstracts of Reviews of Effects (DARE); and ISI BIOSIS Citation index(SM) on 8 February 2013. We reran the searches in August 2014. We will deal with any studies of interest when we update the review.We also searched the Scopus database of dissertations and conference proceedings and the US Food and Drug Administration Database. We handsearched major emergency medicine, critical care, and anaesthesiology journals.We handsearched the conference proceedings of major emergency medicine, anaesthesia, and critical care conferences from 1990 to current, and performed a grey literature search of the following: Current Controlled Trials; National Health Service - The National Research Register; ClinicalTrials.gov; NEAR website.
SELECTION CRITERIA: We included randomized controlled trials in patients undergoing emergency endotracheal intubation for critical illness, including but not limited to trauma, stroke, myocardial infarction, arrhythmia, septic shock, hypovolaemic or haemorrhagic shock, and undifferentiated shock states. We included single (bolus) dose etomidate for emergency airway intervention compared to any other rapid-acting intravenous bolus single-dose induction agent.
DATA COLLECTION AND ANALYSIS: Refinement of our initial search results by title review, and then by abstract review was carried out by three review authors. Full-text review of potential studies was based on their adherence to our inclusion and exclusion criteria. This was decided by three independent review authors. We reported the decisions regarding inclusion and exclusion in accordance with the PRISMA statement.Electronic database searching yielded 1635 potential titles, and our grey literature search yielded an additional 31 potential titles. Duplicate titles were filtered leaving 1395 titles which underwent review of their titles and abstracts by three review authors. Sixty seven titles were judged to be relevant to our review, however only eight met our inclusion criteria and seven were included in our analysis.
MAIN RESULTS: We included eight studies in the review and seven in the meta-analysis. Of those seven studies, only two were judged to be at low risk of bias. Overall, no strong evidence exists that etomidate increases mortality in critically ill patients when compared to other bolus dose induction agents (odds ratio (OR) 1.17; 95% confidence interval (CI) 0.86 to 1.60, 6 studies, 772 participants, moderate quality evidence). Due to a large number of participants lost to follow-up, we performed a post hoc sensitivity analysis. This gave a similar result (OR 1.15; 95% CI 0.86 to 1.53). There was evidence that the use of etomidate in critically ill patients was associated with a positive adrenocorticotropic hormone (ACTH) stimulation test, and this difference was more pronounced at between 4 to 6 hours (OR 19.98; 95% CI 3.95 to 101.11) than after 12 hours (OR 2.37; 95% CI 1.61 to 3.47) post-dosing. Etomidate's use in critically ill patients was associated with a small increase in SOFA score, indicating a higher risk of multisystem organ failure (mean difference (MD) 0.70; 95% CI 0.01 to 1.39, 2 studies, 591 participants, high quality evidence), but this difference was not clinically meaningful. Etomidate use did not have an effect on ICU LOS (MD 1.70 days; 95% CI -2.00 to 5.40, 4 studies, 621 participants, moderate quality evidence), hospital LOS (MD 2.41 days; 95% CI -7.08 to 11.91, 3 studies, 152 participants, moderate quality evidence), duration of mechanical ventilation (MD 2.14 days; 95% CI -1.67 to 5.95, 3 studies, 621 participants, moderate quality evidence), or duration of vasopressor use (MD 1.00 day; 95% CI -0.53 to 2.53, 1 study, 469 participants).
AUTHORS' CONCLUSIONS: Although we have not found conclusive evidence that etomidate increases mortality or healthcare resource utilization in critically ill patients, it does seem to increase the risk of adrenal gland dysfunction and multi-organ system dysfunction by a small amount. The clinical significance of this finding is unknown. This evidence is judged to be of moderate quality, owing mainly to significant attrition bias in some of the smaller studies, and new research may influence the outcomes of our review. The applicability of these data may be limited by the fact that 42% of the patients in our review were intubated for "being comatose", a population less likely to benefit from the haemodynamic stability inherent in etomidate use, and less at risk from its potential negative downstream effects of adrenal suppression.
Techniques, Success, and Adverse Events of Emergency Department Adult Intubations.
Calvin A Brown, Aaron E Bair, Daniel J Pallin, Ron M Walls
Annals of Emergency Medicine 2014 December 19
STUDY OBJECTIVE: We describe the operators, techniques, success, and adverse event rates of adult emergency department (ED) intubation through multicenter prospective surveillance.
METHODS: Eighteen EDs in the United States, Canada, and Australia recorded intubation data onto a Web-based data collection tool, with a greater than or equal to 90% reporting compliance requirement. We report proportions with binomial 95% confidence intervals (CIs) and regression, with year as the dependent variable, to model change over time.
RESULTS: Of 18 participating centers, 5 were excluded for failing to meet compliance standards. From the remaining 13 centers, we report data on 17,583 emergency intubations of patients aged 15 years or older from 2002 to 2012. Indications were medical in 65% of patients and trauma in 31%. Rapid sequence intubation was the first method attempted in 85% of encounters. Emergency physicians managed 95% of intubations and most (79%) were physician trainees. Direct laryngoscopy was used in 84% of first attempts. Video laryngoscopy use increased from less than 1% in the first 3 years to 27% in the last 3 years (risk difference 27%; 95% CI 25% to 28%; mean odds ratio increase per year [ie, slope] 1.7; 95% CI 1.6 to 1.8). Etomidate was used in 91% and succinylcholine in 75% of rapid sequence intubations. Among rapid sequence intubations, rocuronium use increased from 8.2% in the first 3 years to 42% in the last 3 years (mean odds ratio increase per year 1.3; 95% CI 1.3 to 1.3). The first-attempt intubation success rate was 83% (95% CI 83% to 84%) and was higher in the last 3 years than in the first 3 (86% versus 80%; risk difference 6.2%; 95% CI 4.2% to 7.8%). The airway was successfully secured in 99.4% of encounters (95% CI 99.3% to 99.6%).
CONCLUSION: In the EDs we studied, emergency intubation has a high and increasing success rate. Both drug and device selection evolved significantly during the study period.
The C-MAC® Video Laryngoscope Is Superior to the Direct Laryngoscope for the Rescue of Failed First-Attempt Intubations in the Emergency Department
John C Sakles, Jarrod M Mosier, Asad E Patanwala, John M Dicken, Leah Kalin, Parisa P Javedani
Journal of Emergency Medicine 2014 December 11
OBJECTIVE: To compare the effectiveness of the C-MAC® video laryngoscope (CMAC) to the direct laryngoscope (DL) when used to rescue a failed first attempt intubation in the emergency department (ED).
METHODS: Data were prospectively collected on all patients intubated in an academic ED center over a five-year period from February 1, 2009 to January 31, 2014 when both the CMAC and the DL were available. Following each intubation the operator completed a continuous quality improvement (CQI) form documenting patient, operator and intubation characteristics. All orotracheal intubations attempted by emergency physicians (EPs) on adult patients with a failed first intubation attempt, and in which the CMAC or the DL was used for the second attempt, were included. The primary outcome was successful intubation on the second attempt using either the CMAC or the DL. A multivariate logistic regression analysis was performed to adjust for potential confounders.
RESULTS: During the five-year study period, there were 460 adult orotracheal intubation attempts by EPs which were not successful on the first attempt. In 398 (86.5%) of these cases the same operator performed the second attempt. The CMAC was utilized for the second attempt in 141 cases and was successful in 116 (82.3%; 95% CI 75.0%-88.2%) and the DL was utilized in 94 cases and was successful in 58 (61.7%; 95% CI 51.1%-71.5%). In a multivariate logistic regression analysis the CMAC was associated with an increased odds (adjusted OR 3.5; 95% CI 1.9-6.7) of a second attempt success compared to the DL.
CONCLUSIONS: After a failed first intubation attempt in the ED, regardless of the initial device used, the CMAC was more successful than the DL when used for the second attempt. This suggests that the CMAC is the preferred rescue device after an initial intubation attempt in the ED fails.
Comparison of Video Laryngoscopy Versus Direct Laryngoscopy During Urgent Endotracheal Intubation: A Randomized Controlled Trial
Michael J Silverberg, Nan Li, Samuel O Acquah, Pierre D Kory
Critical Care Medicine 2014 December 4
OBJECTIVES: In the critically ill undergoing urgent endotracheal intubation by direct laryngoscopy, multiple attempts are often required with a higher complication rate due to the urgency, uncontrolled setting, comorbidities, and variability in expertise of operators. We hypothesized that Glidescope video laryngoscopy would be superior to direct laryngoscopy during urgent endotracheal intubation.
DESIGN: Single-center prospective randomized controlled trial.
SETTING: Beth Israel Medical Center, an 856-bed urban teaching hospital with a 16-bed closed medical ICU.
PATIENTS: Of 153 consecutive patients undergoing urgent endotracheal intubation by pulmonary and critical care medicine fellows, 117 met inclusion criteria.
INTERVENTIONS: Patients undergoing urgent endotracheal intubation were randomized to Glidescope video laryngoscopy or direct laryngoscopy as the primary intubation device.
MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was the rate of first-attempt success. Acute Physiology and Chronic Health Evaluation II scores were similar between groups (20.9 ± 8.2 vs 19.9 ± 7.9). First-attempt success was achieved in 74% of the Glidescope video laryngoscopy group compared with 40% in the direct laryngoscopy group (p
Does Pre-hospital Endotracheal Intubation Improve Survival in Adults with Non-traumatic Out-of-hospital Cardiac Arrest? A Systematic Review
Ling Tiah, Kentaro Kajino, Omer Alsakaf, Dianne Carrol Tan Bautista, Marcus Eng Hock Ong, Desiree Lie, Ghulam Yasin Naroo, Nausheen Edwin Doctor, Michael Yc Chia, Han Nee Gan.
INTRODUCTION: Endotracheal intubation (ETI) is currently considered superior to supraglottic airway devices (SGA) for survival and other outcomes among adults with non-traumatic out-of-hospital cardiac arrest (OHCA). We aimed to determine if the research supports this conclusion by conducting a systematic review.
METHODS: We searched the MEDLINE, Scopus and CINAHL databases for studies published between January 1, 1980, and 30 April 30, 2013, which compared pre-hospital use of ETI with SGA for outcomes of return of spontaneous circulation (ROSC); survival to hospital admission; survival to hospital discharge; and favorable neurological or functional status. We selected studies using pre-specified criteria. Included studies were independently screened for quality using the Newcastle-Ottawa scale. We did not pool results because of study variability. Study outcomes were extracted and results presented as summed odds ratios with 95% CI.
RESULTS: We identified five eligible studies: one quasi-randomized controlled trial and four cohort studies, involving 303,348 patients in total. Only three of the five studies reported a higher proportion of ROSC with ETI versus SGA with no difference reported in the remaining two. None found significant differences between ETI and SGA for survival to hospital admission or discharge. One study reported better functional status at discharge for ETI versus SGA. Two studies reported no significant difference for favorable neurological status between ETI and SGA.
CONCLUSION: Current evidence does not conclusively support the superiority of ETI over SGA for multiple outcomes among adults with OHCA.
Use of High-Flow Nasal Cannula Oxygen Therapy to Prevent Desaturation During Tracheal Intubation of Intensive Care Patients With Mild-to-Moderate Hypoxemia
Romain Miguel-Montanes, David Hajage, Jonathan Messika, Fabrice Bertrand, Stéphane Gaudry, Cédric Rafat, Vincent Labbé, Nicolas Dufour, Sylvain Jean-Baptiste, Alexandre Bedet, Didier Dreyfuss, Jean-Damien Ricard.
Critical Care Medicine 2014 December 4
OBJECTIVES: Tracheal intubation of ICU patients is frequently associated with severe hypoxemia. Although noninvasive ventilation reduces desaturation during intubation of severely hypoxemic patients, it does not allow for per-procedure oxygenation and has not been evaluated in mild-to-moderate hypoxemic patients for whom high-flow nasal cannula oxygen may be an alternative. We sought to compare pre- and per-procedure oxygenation with either a nonrebreathing bag reservoir facemask or a high-flow nasal cannula oxygen during tracheal intubation of ICU patients.
DESIGN: Prospective quasi-experimental before-after study (ClinicalTrials.gov: NCT01699880).
SETTING: University hospital medico-surgical ICU.
PATIENTS: All adult patients requiring tracheal intubation in the ICU were eligible.
INTERVENTIONS: In the control (before) period, preoxygenation was performed with a nonrebreathing bag reservoir facemask and in the change of practice (after) period, with high-flow nasal cannula oxygen.
MEASUREMENTS AND MAIN RESULTS: Primary outcome was median lowest SpO2 during intubation, and secondary outcomes were SpO2 after preoxygenation and number of patients with saturation less than 80%. One hundred one patients were included. Median lowest SpO2 during intubation were 94% (83-98.5) with the nonrebreathing bag reservoir facemask versus 100% (95-100) with high-flow nasal cannula oxygen (p
Delayed Sequence Intubation: A Prospective Observational Study
Scott D Weingart, N Seth Trueger, Nelson Wong, Joseph Scofi, Neil Singh, Soren S Rudolph.
Annals of Emergency Medicine 2014 October 23
STUDY OBJECTIVE: We investigate a new technique for the emergency airway management of patients with altered mental status preventing adequate preoxygenation.
METHODS: This was a prospective, observational, multicenter study of patients whose medical condition led them to impede optimal preintubation preparation because of delirium. A convenience sample of emergency department and ICU patients was enrolled. Patients received a dissociative dose of ketamine, allowing preoxygenation with high-flow nonrebreather mask or noninvasive positive pressure ventilation (NIPPV). After preoxygenation, patients were paralyzed and intubated. The primary outcome of this study was the difference in oxygen saturations after maximal attempts at preoxygenation before delayed sequence intubation compared with saturations just before intubation. Predetermined secondary outcomes and complications were also assessed.
RESULTS: A total of 62 patients were enrolled: 19 patients required delayed sequence intubation to allow nonrebreather mask, 39 patients required it to allow NIPPV, and 4 patients required it for nasogastric tube placement. Saturations increased from a mean of 89.9% before delayed sequence intubation to 98.8% afterward, with an increase of 8.9% (95% confidence interval 6.4% to 10.9%). Thirty-two patients were in a predetermined group with high potential for critical desaturation (pre-delayed sequence intubation saturations ≤93%). All of these patients increased their saturations post-delayed sequence intubation; 29 (91%) of these patients increased their post-delayed sequence intubation saturations to greater than 93%. No complications were observed in the patients receiving delayed sequence intubation.
CONCLUSION: Delayed sequence intubation could offer an alternative to rapid sequence intubation in patients requiring emergency airway management who will not tolerate preoxygenation or peri-intubation procedures. It is essentially procedural sedation, with the procedure being preoxygenation. Delayed sequence intubation seems safe and effective for use in emergency airway management.