A Comparison of Video Laryngoscopy to Direct Laryngoscopy for the Emergency Intubation of Trauma Patients

First-Pass Success of Intubations Using Video Versus Direct Laryngoscopy in Children With Limited Neck Mobility

OBJECTIVE

It is not clear whether video laryngoscopy (VL) is associated with a higher first-pass success rate in pediatric patients with limited neck mobility when compared with direct laryngoscopy (DL). We sought to determine the association between the laryngoscopy method and first-pass success.

METHODS

In this retrospective cohort study, we examined intubation data extracted from 2 prospectively collected, multicenter, airway management safety databases (National Emergency Airway Registry and the National Emergency Airway Registry for children), obtained during the years 2013-2018 in the emergency department. Intubations were included if patients were aged younger than 18 and had limited neck mobility. We compared first-pass success rates for ED intubations that were performed using VL versus DL. We built a structural causal model to account for potential confounders such as age, disease category (medical or trauma condition), other difficult airway characteristics, use of sedatives/paralytics, and laryngoscopist training level. We also analyzed adverse events as a secondary outcome.

RESULTS

Of 34,239 intubations (19,071 in the National Emergency Airway Registry and 15,168 in the National Emergency Airway Registry for children), a total of 341 intubations (1.0%) met inclusion criteria; 168 were performed via VL and 173 were performed via DL. The median age of patients was 124 months (interquartile range, 48-204). There was no difference in first-pass success between VL and DL (79.8% vs 75.7%, P = 0.44). Video laryngoscopy was not associated with higher first-pass success (odds ratio, 1.11; 95% confidence interval 0.84-1.47, with DL as a comparator) when a structural causal model was used to account for confounders. There was no difference in the adverse events between VL and DL groups (13.7% vs 8.7%, P = 0.19).

CONCLUSION

In children with limited neck mobility receiving tracheal intubation in the ED, neither VL nor DL was associated with a higher first-pass success rate.

Video Laryngoscopy vs Direct Laryngoscopy for Endotracheal Intubation in the Operating Room: A Cluster Randomized Clinical Trial

Importance

Endotracheal tubes are typically inserted in the operating room using direct laryngoscopy. Video laryngoscopy has been reported to improve airway visualization; however, whether improved visualization reduces intubation attempts in surgical patients is unclear.

Objective

To determine whether the number of intubation attempts per surgical procedure is lower when initial laryngoscopy is performed using video laryngoscopy or direct laryngoscopy.

Design, Setting, and Participants

Cluster randomized multiple crossover clinical trial conducted at a single US academic hospital. Patients were adults aged 18 years or older having elective or emergent cardiac, thoracic, or vascular surgical procedures who required single-lumen endotracheal intubation for general anesthesia. Patients were enrolled from March 30, 2021, to December 31, 2022. Data analysis was based on intention to treat.

Interventions

Two sets of 11 operating rooms were randomized on a 1-week basis to perform hyperangulated video laryngoscopy or direct laryngoscopy for the initial intubation attempt.

Main Outcomes and Measures

The primary outcome was the number of operating room intubation attempts per surgical procedure. Secondary outcomes were intubation failure, defined as the responsible clinician switching to an alternative laryngoscopy device for any reason at any time, or by more than 3 intubation attempts, and a composite of airway and dental injuries.

Results

Among 8429 surgical procedures in 7736 patients, the median patient age was 66 (IQR, 56-73) years, 35% (2950) were women, and 85% (7135) had elective surgical procedures. More than 1 intubation attempt was required in 77 of 4413 surgical procedures (1.7%) randomized to receive video laryngoscopy vs 306 of 4016 surgical procedures (7.6%) randomized to receive direct laryngoscopy, with an estimated proportional odds ratio for the number of intubation attempts of 0.20 (95% CI, 0.14-0.28; P < .001). Intubation failure occurred in 12 of 4413 surgical procedures (0.27%) using video laryngoscopy vs 161 of 4016 surgical procedures (4.0%) using direct laryngoscopy (relative risk, 0.06; 95% CI, 0.03-0.14; P < .001) with an unadjusted absolute risk difference of -3.7% (95% CI, -4.4% to -3.2%). Airway and dental injuries did not differ significantly between video laryngoscopy (41 injuries [0.93%]) vs direct laryngoscopy (42 injuries [1.1%]).

Conclusion and Relevance

In this study among adults having surgical procedures who required single-lumen endotracheal intubation for general anesthesia, hyperangulated video laryngoscopy decreased the number of attempts needed to achieve endotracheal intubation compared with direct laryngoscopy at a single academic medical center in the US. Results suggest that video laryngoscopy may be a preferable approach for intubating patients undergoing surgical procedures.

Trial Registration

ClinicalTrials.gov Identifier: NCT04701762.

Video laryngoscopy versus direct laryngoscopy in achieving successful emergency endotracheal intubations: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Intubating a patient in an emergent setting presents significant challenges compared to planned intubation in an operating room. This study aims to compare video laryngoscopy versus direct laryngoscopy in achieving successful endotracheal intubation on the first attempt in emergency intubations, irrespective of the clinical setting.

METHODS

We systematically searched PubMed, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception until 27 February 2023. We included only randomized controlled trials that included patients who had undergone emergent endotracheal intubation for any indication, regardless of the clinical setting. We used the Cochrane risk-of-bias assessment tool 2 (ROB2) to assess the included studies. We used the mean difference (MD) and risk ratio (RR), with the corresponding 95% confidence interval (CI), to pool the continuous and dichotomous variables, respectively.

RESULTS

Fourteen studies were included with a total of 2470 patients. The overall analysis favored video laryngoscopy over direct laryngoscopy in first-attempt success rate (RR = 1.09, 95% CI [1.02, 1.18], P = 0.02), first-attempt intubation time (MD =  - 6.92, 95% CI [- 12.86, - 0.99], P = 0.02), intubation difficulty score (MD =  - 0.62, 95% CI [- 0.86, - 0.37], P < 0.001), peri-intubation percentage of glottis opening (MD = 24.91, 95% CI [11.18, 38.64], P < 0.001), upper airway injuries (RR = 0.15, 95% CI [0.04, 0.56], P = 0.005), and esophageal intubation (RR = 0.37, 95% CI [0.15, 0.94], P = 0.04). However, no difference between the two groups was found regarding the overall intubation success rate (P > 0.05).

CONCLUSION

In emergency intubations, video laryngoscopy is preferred to direct laryngoscopy in achieving successful intubation on the first attempt and was associated with a lower incidence of complications.

Characterizing intubation practices in response to the COVID-19 pandemic: a survey of the Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN) sites

OBJECTIVE

The risk of occupational exposure during endotracheal intubation has required the global Emergency Medicine (EM), Anesthesia, and Critical Care communities to institute new COVID- protected intubation guidelines, checklists, and protocols. This survey aimed to deepen the understanding of the changes in intubation practices across Canada by evaluating the pre-COVID-19, early-COVID-19, and present-day periods, elucidating facilitators and barriers to implementation, and understanding provider impressions of the effectiveness and safety of the changes made.

METHODS

We conducted an electronic, self-administered, cross-sectional survey of EM physician site leads within the Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN) to characterize and compare airway management practices in the pre-COVID-19, early-COVID-19, and present-day periods. Ethics approval for this study was obtained from the University of Manitoba Health Research Ethics Board. The electronic platform SurveyMonkey ( www.surveymonkey.com ) was used to collect and store survey tool responses. Categorical item responses, including the primary outcome, are reported as numbers and proportions. Variations in intubation practices over time were evaluated through mixed-effects logistic regression models.

RESULTS

Invitations were sent to 33 emergency department (ED) physician site leads in the CCEDRRN. We collected 27 survey responses, 4 were excluded, and 23 analysed. Responses were collected in English (87%) and French (13%), from across Canada and included mainly physicians practicing in mainly Academic and tertiary sites (83%). All respondents reported that the intubation protocols used in their EDs changed in response to the COVID-19 pandemic (100%, n = 23, 95% CI 0.86-1.00).

CONCLUSIONS

This study provides a novel summary of changes to airway management practices in response to the evolving COVID-19 pandemic in Canada. Information from this study could help inform a consensus on safe and effective emergent intubation of persons with communicable respiratory infections in the future.

Comparison of Force During the Endotracheal Intubation of Commercial Simulation Manikins

Background  Medical simulation allows clinicians to safely practice the procedural skill of endotracheal intubation. Applied force to oropharyngeal structures increases the risk of patient harm, and video laryngoscopy (VL) requires less force to obtain a glottic view. It is unknown how much force is required to obtain a glottic view using commercially available simulation manikins and if variability exists. This study compares laryngoscopy force for a modified Cormack-Lehane (CL) grade I view in both normal and difficult airway scenarios between three commercially available simulation manikins. Methods Experienced clinicians (≥2 years experience) were recruited to participate from critical care, emergency medicine, and anesthesia specialties. A C-MAC size 3 VL blade was equipped with five force resistor reading (FSR) sensors (four concave surfaces, one convex), measuring resistance (Ohms) in response to applied pressure (1-100 Newtons). The study occurred in a university simulation lab. Using a randomized sequence, 49 physicians performed intubations on three manikins (Laerdal SimMan 3GPlus, Gaumard Hal S3201, CAE Apollo) in normal and difficult airway scenarios. The outcomes were sensor mean pressure, peak force, and CL grade. Summary statistics were calculated. Generalized estimating equations (GEEs) conducted for both scenarios assessed changes in pressure measured in three manikins while accounting for correlated responses of individuals assigned in random order. Paired t-test assessed for the in-manikin difference between scenarios. STATA/BE v17 (R) was used for analysis; results interpreted at type I error alpha is 0.05.  Results Participants included 49 experienced clinicians. Mean years' experience was 4(±6.6); median prior intubations were 80 (IQR 50-400). Mean individual sensor pressure varied within scenarios depending on manikin (p<0.001). Higher mean forces were used in difficult scenarios (603.4±128.9, 611.1±101.4, 467.5±72.4 FSR) than normal (462.5±121.9, 596.0±90.5, 290.6±63.2 FSR) for each manikin (p<0.001). All manikins required more peak force in the difficult scenario (p<0.03). The highest mean forces (Laerdal, CAE, difficult scenario) were associated with the higher frequency of grade 2A views (p<0.001). The Gaumard manikin was rated most realistic in terms of force required to intubate. Conclusion Commercially available high-fidelity manikins had significant variability in laryngoscopy force in both normal and difficult airway scenarios. In difficult airway scenarios, significant variability existed in CL grade between manikin brands. Experienced clinicians rated Gaumard Hal as the most realistic force applied during endotracheal intubation.

Evaluating the Usability of a 3D-Printed Video Laryngoscope for Tracheal Intubation of a Manikin

Background

Compared to direct laryngoscopy, videolaryngoscopy (VL) can provide improved laryngeal and glottic view, higher intubation success rates in patients with a known or predicted difficult airway and reduced incidence of laryngeal/airway trauma. However, the cost and availability of these devices handicap its use in resource-restricted facilities. The objective was to design and manufacture a novel VL using additive manufacturing (AM) and evaluate its usability on an intubation manikin by comparing it to one of the most common video laryngoscopes used in clinical practice, the CMAC^®, by measuring the time to first pass of the endotracheal tube as the main outcome.

Methods

A randomised cross-over study was performed with 36 anaesthetists attempting tracheal intubation of a manikin. The novel 3D-printed hyperangulated VL blade was compared to a CMAC^® VL (D-blade). Participants had no prior experience or training with the novel device. The participants included consultants, registrars/trainees and medical officers in the Department of Anaesthesiology at the University of the Free State (UFS) in South Africa.

Results

The CMAC^® had a statistically shorter time to first pass (median 13.8 seconds) compared to the 3D-printed model (median 19.0 seconds) (95% confidence interval [CI] 1.0-6.2; P=0.0013). No failed attempts occurred with either device.

Conclusion

Intubation times were faster with the CMAC^® than with the novel device. However, with a comparable intubation success rate, 3D printing technology potentially can improve access to video laryngoscopy. Further design improvements, validation of materials and manufacturing processes are required before 3D-printed laryngoscope blades can be used in human subjects.

Pro-Con Debate: Videolaryngoscopy Should Be Standard of Care for Tracheal Intubation

In this Pro-Con commentary article, we discuss whether videolaryngoscopy (VL) should be the standard of care for tracheal intubation. Dr Aziz makes the case that VL should be the standard of care, while Dr Berkow follows with a challenge of that assertion. In this debate, we explore not only the various benefits of VL, but also its limitations. There is compelling evidence that VL improves first-pass success rates, reduces the risk of intubation failure and esophageal intubation, and has benefits in the difficult airway patient. But VL is not without complications and does not possess a 100% success rate. In the case of failure, it is important to have back-up plans for airway management. While transition of care from direct laryngoscopy (DL) to VL may result in improved airway management outcomes, the reliance on VL may degrade other important clinical skills when they are needed most. If VL is adapted as the standard of care, airway managers may no longer practice and retain competency in other airway techniques that may be required in the event of VL failure. While cost is a barrier to broad implementation of VL, those costs are normalizing. However, it may still be challenging for institutions to secure purchase of VL for every intubating location, as well as back-up airway devices. As airway management care increasingly transitions from DL to VL, providers should be aware of the benefits and risks to this practice change.

A prospective observational study comparing outcomes before and after the introduction of an intubation protocol during the COVID-19 pandemic

OBJECTIVE

Orotracheal intubation is a life-saving procedure commonly performed in the Intensive Care unit and Emergency Department as a part of emergency airway management. Prior to the COVID-19 pandemic, our center undertook a prospective observational study to characterize emergency intubation performed in the emergency department and critical care settings at Manitoba's largest tertiary hospital. During this study, a natural experiment emerged when a standardized "COVID-Protected Rapid Sequence Intubation Protocol" was implemented in response to the pandemic. The resultant study aimed to answer the question; in adult ED patients undergoing emergent intubation by EM and CCM teams, does the use of a "COVID-Protected Rapid Sequence Intubation Protocol" impact first-pass success or other intubation-related outcomes?

METHODS

A single-center prospective quasi-experimental before and after study was conducted. Data were prospectively collected on consecutive emergent intubations. The primary outcome was the difference in first-pass success rates. Secondary outcomes included best Modified Cormack-Lehane view, hypoxemia, hypotension, esophageal intubation, cannot intubate cannot oxygenate scenarios, CPR post intubation, vasopressors required post intubation, Intensive Care Unit (ICU) mortality, ICU length of stay (LOS), and mechanical ventilation days.

RESULTS

Data were collected on 630 patients, 416 in the pre-protocol period and 214 in the post-protocol period. First-pass success rates in the pre-protocol period were found to be 73.1% (n = 304). Following the introduction of the protocol, first-pass success rates increased to 82.2% (n = 176, p = 0.0105). There was a statistically significant difference in Modified Cormack-Lehane view favoring the protocol (p = 0.0191). Esophageal intubation rates were found to be 5.1% pre-protocol introduction versus 0.5% following the introduction of the protocol (p = 0.0172).

CONCLUSION

A "COVID-Protected Protocol" implemented by Emergency Medicine and Critical Care teams in response to the COVID-19 pandemic was associated with increased first-pass success rates and decreases in adverse events.

The use of video laryngoscopy outside the operating room: A systematic review

This study aimed to describe how video laryngoscopy is used outside the operating room within the hospital setting. Specifically, we aimed to summarise the evidence for the use of video laryngoscopy outside the operating room, and detail how it appears in current clinical practice guidelines. A literature search was conducted across two databases (MEDLINE and Embase), and all articles underwent screening for relevance to our aims and pre-determined exclusion criteria. Our results include 14 clinical practice guidelines, 12 interventional studies, 38 observational studies. Our results show that video laryngoscopy is likely to improve glottic view and decrease the incidence of oesophageal intubations; however, it remains unclear as to how this contributes to first-pass success, overall intubation success and clinical outcomes such as mortality outside the operating room. Furthermore, our results indicate that the appearance of video laryngoscopy in clinical practice guidelines has increased in recent years, and particularly through the COVID-19 pandemic. Current COVID-19 airway management guidelines unanimously introduce video laryngoscopy as a first-line (rather than rescue) device.

Direct vs Video Laryngoscopy for Difficult Airway Patients in the Emergency Department: A National Emergency Airway Registry Study

Introduction: Previous studies suggest improved intubation success using video laryngoscopy (VL) vs direct laryngoscopy (DL), yet recent randomized trials have not shown clear benefit of one method over the other. These studies, however, have generally excluded difficult airways and rapid sequence intubation. In this study we looked to compare first-pass success (FPS) rates between VL and DL in adult emergency department (ED) patients with difficult airways. Methods: We conducted a secondary analysis of prospectively collected observational data in the National Emergency Airway Registry (NEAR) (January 2016–December 2018). Variables included demographics, indications, methods, medications, devices, difficult airway characteristics, success, and adverse events. We included adult ED patients intubated with VL or DL who had difficult airways identified by gestalt or anatomic predictors. We stratified VL by hyperangulated (HAVL) vs standard geometry VL (SGVL). The primary outcome was FPS, and the secondary outcome was comparison of adverse event rates between groups. Data analyses included descriptive statistics with cluster-adjusted 95% confidence intervals (CI). Results: Of 18,123 total intubations, 12,853 had a predicted or identified anatomically difficult airway. The FPS for difficult airways was 89.1% (95% CI 85.9-92.3) with VL and 77.7% (95% CI 75.7-79.7) with DL (P <0.00001). The FPS rates were similar between VL subtypes for all difficult airway characteristics except airways with blood or vomit, where SGVL FPS (87.3%; 95% CI 85.8-88.8) was slightly better than HAVL FPS (82.4%; 95% CI, 80.3-84.4). Adverse event rates were similar except for esophageal intubations and vomiting, which were both less common in VL than DL. Esophageal intubations occurred in 0.4% (95% CI 0.1-0.7) of VL attempts and 1.5% (95% CI 1.1-1.9) of DL attempts. Vomiting occurred in 0.6% (95% CI 0.5-0.7) of VL attempts and 1.4% (95% CI 0.9-1.9) of DL attempts. Conclusion: Analysis of the NEAR database demonstrates higher first-pass success with VL compared to DL in patients with predicted or anatomically difficult airways, and reduced rate of esophageal intubations and vomiting.

Comparison Between McCoy Laryngoscope and C-MAC Video Laryngoscope in Anticipated Difficult Airway: A Prospective Randomised Study

Objective: Prolonged laryngoscopy and failure to intubate are associated with increased morbidity and mortality. Need to improve glottic visualisation and ease of intubation has led to the introduction of various types of laryngoscopes. This study compares the effectiveness of C-MAC video laryngoscope (VL) with McCoy laryngoscope in patients with an anticipated difficult airway.

Methods: This prospective randomised single-blinded single-centre study included patients with modified Mallampati grades 3 and 4, divided into two groups I and II of 65 patients each. Group I was intubated using C-MAC and group II with McCoy Laryngoscope. Modified Cormack Lehane grade of visualisation, time to intubate, intubation difficulty scale score and complications were recorded.

Results: C-MAC VL provides a higher proportion of modified Cormack Lehane grade I visualisation (63% vs 35.3, p=0.0017), the lesser median time of intubation in seconds (15 vs 18, p=0.0007) and significantly lesser median intubation difficulty score (0 vs 3) when compared to McCoy.

Conclusions: C-MAC VL provided better visualisation of glottis and easier tracheal intubation that too in a significantly lesser time. We conclude and recommend the use of C-MAC VL over McCoy for endotracheal intubation in patients with predicted difficult airways, especially in modified Mallampati grades 3 and 4.

Updated guideline on equipment to manage difficult airways: Australian and New Zealand College of Anaesthetists

The Australian and New Zealand College of Anaesthetists (ANZCA) recently reviewed and updated the guideline on equipment to manage a difficult airway. An ANZCA-established document development group, which included representatives from the Australasian College for Emergency Medicine and the College of Intensive Care Medicine of Australia and New Zealand, performed the review, which is based on expert consensus, an extensive literature review, and bi-nationwide consultation. The guideline (PG56(A) 2021, https://www.anzca.edu.au/getattachment/02fe1a4c-14f0-4ad1-8337-c281d26bfa17/PS56-Guideline-on-equipment-to-manage-difficult-airways) is accompanied by a detailed background paper (PG56(A)BP 2021, https://www.anzca.edu.au/getattachment/9ef4cd97-2f02-47fe-a63a-9f74fa7c68ac/PG56(A)BP-Guideline-on-equipment-to-manage-difficult-airways-Background-Paper), from which the current recommendations are reproduced on behalf of, and with the permission of, ANZCA. The updated 2021 guideline replaces the 2012 version and aims to provide an updated, objective, informed, transparent, and evidence-based review of equipment to manage difficult airways.

Re-creating reality: validation of fresh frozen full cadaver airway training with videolaryngoscopy and bougie FIRST strategy

Background

Tracheal intubation is the gold standard in emergency airway management. One way of measuring intubation quality is first pass success rate (FPSR). Mastery of tracheal intubation and maintenance of the skill is challenging for non-anesthesiologists. A combination of individual measures can increase FPSR. Videolaryngoscopy is an important tool augmenting laryngeal visualization. Bougie-first strategy can further improve FPSR in difficult airways. Standardized positioning maneuvers and manipulation of the soft tissues can enhance laryngeal visualization. Fresh frozen cadavers (FFC) are superior models compared to commercially manufactured manikins. By purposefully manipulating FFCs, it is possible to mimic the pre-hospital intubation conditions of helicopter emergency medical service (HEMS).

Methods

Twenty-four trauma surgeons (12 per Group, NOVICES: no pre-hospital experience, HEMS: HEMS physicians) completed an airway training course using FFCs. The FFCs were modified to match airway characteristics of 60 prospectively documented intubations by HEMS physicians prior to the study (BASELINE). In four scenarios the local HEMS airway standard (1: unaided direct laryngoscopy (DL), OLD) was compared to two scenarios with modifications of the intubation technique (2: augmented DL (bougie and patient positioning), 3: augmented videolaryngoscopy (aVL)) and a control scenario (4: VL and bougie, positioning by participant, CONTROL). FPSR, POGO score, Cormack and Lehane grade and duration of intubation were recorded. No participant had anesthesiological qualifications or experience in VL.

Results

The comparison between CONTROL and BASELINE revealed a significant increase of FPSR and achieved C&L grade for HEMS group (FPSR 100%, absolute difference 23%, p ≤ .001). The use of videolaryngoscopy, bougie, and the application of positioning techniques required significantly more time in the CONTROL scenario (HEMS group: mean 34.0 s (IQR 28.3–47.5), absolute difference to BASELINE: 13.0 s, p = .045). The groups differed significantly in the median number of real-life intubations performed in any setting (NOVICES n = 5 (IQR 0–18.75), HEMS n = 68 (IQR 37.25–99.75)). In the control scenario no significant differences were found between both groups. The airway characteristics of the FFC showed no significant differences compared to BASELINE.

Conclusion

Airway characteristics of a pre-hospital patient reference group cared for by HEMS were successfully reproduced in a fresh frozen cadaver model. In this setting, a combination of evidence based airway management techniques results in high FPSR and POGO rates of non-anesthesiological trained users. Comparable results (FPSR, POGO, duration of intubation) were achieved regardless of previous provider experience. The BOAH concept can therefore be used in the early stages of airway training and for skill maintenance.

Video screen visualization patterns when using a video laryngoscope for tracheal intubation: A systematic review

OBJECTIVE

Published studies of video laryngoscopes are often limited by the lack of a clear definition of video laryngoscopy (VL). We performed a systematic review to determine how often published studies of VL report on video screen visualization.

METHODS

We searched PubMed, EMBASE and Scopus for interventional and observational studies in which a video laryngoscope equipped with a standard geometry blade was used for tracheal intubation. We excluded simulation based studies. Our primary outcome was data on video laryngoscope screen visualization. Secondary outcomes were explicit methodology for screen visualization.

RESULTS

We screened 4838 unique studies and included 207 (120 interventional and 87 observational). Only 21 studies (10% of 207) included any data on video screen visualization by the proceduralist, 19 in a yes/no fashion only (ie, screened viewed or not) and 2 with detail beyond whether the screen was viewed or not. In 11 more studies, visualization patterns could be inferred based on screen availability and in 16 more studies, the methods section stated how screen visualization was expected to be performed without reporting data collection on how the proceduralist interacted with the video screen. Risk of bias was high in the majority of included studies.

CONCLUSIONS

Published studies of VL, including many clinical trials, rarely include data on video screen visualization. Given the nuances of using a video laryngoscope, this is a critical deficiency, which largely prevents us from knowing the treatment effect of using a video laryngoscope in clinical practice. Future studies of VL must address this deficiency.

2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway

The American Society of Anesthesiologists; All India Difficult Airway Association; European Airway Management Society; European Society of Anaesthesiology and Intensive Care; Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care; Learning, Teaching and Investigation Difficult Airway Group; Society for Airway Management; Society for Ambulatory Anesthesia; Society for Head and Neck Anesthesia; Society for Pediatric Anesthesia; Society of Critical Care Anesthesiologists; and the Trauma Anesthesiology Society present an updated report of the Practice Guidelines for Management of the Difficult Airway.

Comparison of the time to successful endotracheal intubation using the Macintosh laryngoscope or KingVision video laryngoscope in the emergency department: A prospective observational study

OBJECTIVE:

Intubation is a skill that must be mastered by the emergency physician (EP). Today, we have a host of video laryngoscopes which have been developed to make intubations easier and faster. It may seem that in a busy emergency department (ED), a video laryngoscope (VL) in the hands of an EP would help him intubate patients faster compared to the traditional direct laryngoscope (DL). Our goal was to compare the time taken to successfully intubate patients coming in ED using King Vision VL (KVVL) and DL.

MATERIALS AND METHODS:

This was a prospective observational study on patients coming to the ED requiring emergent intubation. They were allocated one to one alternatively into two groups – KVVL and DL. Accordingly, KVVL or DL intubations were carried out by the EPs. Time taken to intubate, first-pass success, and crossover between laryngoscopes were recorded.

RESULTS:

A total of 350 patients were enrolled in the study. Overall, mean time to intubate patients using the DL was 15.85 s (95% confidence interval [CI] 14.05–17.65), while the meantime with KVVL was 13.75 s (95% CI 12.32–15.18) (P = 0.084). The overall first-pass success rates with DL and KVVL were 89.94% and 85.16%, respectively (P = 0.076). A total of 7.43% (95% CI 5.12–10.66) patients had crossover between laryngoscopes.

CONCLUSION:

We found the KVVL to have a similar performance to the DL in terms of time for intubations and ease in difficult airways. We consider the KVVL a useful device for EDs to equip themselves with.

Does video laryngoscopy or direct laryngoscopy affect first-pass success rates for intubation among attending and non-attending emergency physicians in the emergency department?

Background:

To our knowledge, there has been no study comparing intubation characteristics between attending and non-attending emergency physicians in Southeast Asia. We aim to identify whether the use of direct laryngoscopy compared to video laryngoscopy affects first-pass success rates between attending emergency physicians and non-attending emergency physicians.

Materials and methods:

Retrospective analysis of data from 2009 to 2016 in an existing airway registry managed by an academic Emergency Department in Singapore. Primary outcome was first-pass success intubation rate. Secondary outcome was first-pass success rate for difficult intubations. Difficult intubations were defined as LEMON (Look externally, Evaluate 3-3-2 rule, Mallampati score, Obstruction, Neck mobility) score of more than 1.

Results:

There were a total of 2909 intubations. Attending emergency physicians conducted 1748 intubations, while non-attending emergency physicians conducted 1161 intubations. The first-pass success rates for AEP were 84.2% and 67.4% for non-attending emergency physicians. Direct laryngoscopy was used in 86.2% of intubation by attending emergency physicians compared to 89.0% in the intubation by non-attending emergency physicians. Also, 7.6% of intubations by the attending emergency physicians were difficult compared to 8.8% by the non-attending emergency physicians (p = 0.25). Logistic regression of the effect of laryngoscopy device on first-pass success in all intubations showed a negative association with video laryngoscopy (odds ratio, 0.70; 95% confidence interval, 0.56–0.88). In the subgroup of difficult intubations, non-attending emergency physicians are 1.54 times (95% confidence interval, 0.53–4.42) as likely to have first-pass success with video laryngoscopy compared to that with direct laryngoscopy. On the contrary, in the subgroup of difficult intubations, attending emergency physicians are 0.90 times (95% confidence interval, 0.38–2.12) as likely to have first-pass success with video laryngoscopy compared to that with direct laryngoscopy.

Conclusion:

Our study showed that video laryngoscopy has a lower first-pass success rate for all intubations in general. Intubations performed by attending emergency physicians with direct laryngoscopy were associated with a higher first-pass success rate.

Airway management at Level 1 trauma center in the era of video laryngoscopy

Background

Rapid sequence induction and tracheal intubation through direct laryngoscopy (DL) has been the most common approach to secure the airway in trauma patients. The introduction of video laryngoscopy (VL) has changed airway management in many clinical settings. In this retrospective study, we assessed if immediate availability of VL in the trauma suite has changed the approach and outcomes of airway management during acute resuscitation at a dedicated trauma center.

Materials and Methods

We retrospectively collected data from emergency intubation in the 6 resuscitation bays at a high-volume, academic, Level 1 trauma center over a 42-month period following the introduction of immediately available VL in the resuscitation bay. We divided the data into 13-week bins to assess the trend in the use of VL over time. Our measured outcomes were the incidence of failed intubations requiring a surgical airway and the frequency of VL use for airway management.

Results

Among 1328 airway management events in the resuscitation bays when intubation was attempted, the failure rate resulting in the placement of a surgical airway was 0.38% (95% confidence interval [CI], 0.12% -0.88%). This was consistent with the surgical airway rate before the introduction of VL into trauma practice (0.3%). VL use (primary or as a rescue technique) throughout the study period was 4.14% (95% CI, 2.76%-5.74%), with no temporal trend.

Conclusion

The immediate availability of VL in the resuscitation bay has not changed the prevalence of its use during emergency airway management at our trauma center. DL remains a preferred primary modality for airway management by the trauma anesthesiologists working at this facility, with an acceptably low incidence of both primary failure and the need to establish a surgical airway.

Comparison of adverse events between video and direct laryngoscopes for tracheal intubations in emergency department and ICU patients-a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis was designed to determine whether video laryngoscope (VL) compared with direct laryngoscope (DL) could reduce the occurrence of adverse events associated with tracheal intubation in the emergency and ICU patients.

METHODS

The current issue of Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Web of Science (from database inception to October 30, 2018) were searched. The RCTs, quasi-RCTs, observational studies comparing VL and DL for tracheal intubation in emergency or ICU patients and reporting the rates of adverse events were included. The primary outcome was the rate of esophageal intubation (EI). Review Manager 5.3 software was used to perform the pooled analysis and assess the risk of bias for each eligible RCT. The ACROBAT-NRSi Cochrane Risk of Bias Tool was applied to assess the risk of bias for each eligible observational study.

RESULTS

Twenty-three studies (13,117 patients) were included in the review for data extraction. Pooled analysis showed a lower rate of EI by using VL (relative risk [RR], 0.24; P < 0.01; high-quality evidence for RCTs and very low-quality evidence for observational studies). Subgroup analyses based on the type of studies, whether a cardiopulmonary resuscitation study, or operators' expertise showed a similar lower rate of EI by using VL compared with DL in all subgroups (P < 0.01) except for experienced operators (RR, 0.44; P = 0.09). There were no significant differences between devices for other adverse events (P > 0.05), except for a lower incidence of hypoxemia when intubation was performed with VL by inexperienced operators (P = 0.03).

CONCLUSIONS

Based on the results of this analysis, we conclude that compared with DL, VL can reduce the risk of EI during tracheal intubation in the emergency and ICU patients, but does not provide significant benefits on other adverse events associated with tracheal intubation.

Video Laryngoscopy Compared to Augmented Direct Laryngoscopy in Adult Emergency Department Tracheal Intubations: A National Emergency Airway Registry (NEAR) Study

OBJECTIVE

The objective was to compare first-attempt intubation success using direct laryngoscopy augmented by laryngeal manipulation, ramped patient positioning, and use of a bougie (A-DL) with unaided video laryngoscopy (VL) in adult emergency department (ED) intubations.

METHODS

This study was a secondary analysis of a multicenter prospective observational database of ED intubations from the National Emergency Airway Registry (NEAR). We compared all VL procedures to seven exploratory permutations of A-DL using multivariable regression models. We further stratified by blade shape into hyperangulated VL (HA-VL) and standard-geometry VL (SG-VL). We report differences in first-attempt intubation success and peri-intubation adverse events with cluster-adjusted odds ratios (ORs) with 95% confidence intervals (CIs). We report univariate comparisons in patient characteristics, difficult airway attributes, and intubation methods using descriptive statistics and OR with 95% CI.

RESULTS

We analyzed 11,714 intubations performed from January 1, 2016, through December 31, 2017. Of these encounters, 6,938 underwent orotracheal intubation with either A-DL or unaided VL on first attempt. A-DL was used first in 3,936 (56.7%, 95% CI = 46.9 to 66.5) versus unaided VL in 3,002 (43.3%, 95% CI = 33.5 to 53.1). Of the A-DL first intubations 1,787 (45.4%) employed ramped positioning alone, 1,472 (37.4%) had external laryngeal manipulation (ELM), and 365 (9.3%) used a bougie. Rapid sequence intubation (RSI) was the most common method used in 5,602 (80.8%, 95% CI = 77.0 to 84.5) cases. First-attempt success was significantly higher with all VL (90.9%, 95% CI = 88.7 to 93.1) versus all A-DL (81.1%, 95% CI = 78.7 to 83.5) despite the VL group having more patients with reduced mouth opening, neck immobility, and an initial impression of airway difficult. Multivariable regression analyses controlling for indication, method, operator specialty and year of training, center clustering, and all registry-recorded difficult airway predictors revealed first-attempt success was higher with all unaided VL compared with any A-DL (adjusted OR [AOR] = 2.8, 95% CI = 2.4 to 3.3), DL with bougie (AOR = 2.7, 95% CI = 2.1 to 3.5), DL with ELM (AOR = 1.8, 95% CI = 1.5 to 2.2), DL with ramped positioning (AOR = 2.8, 95% CI = 2.3 to 3.3), or DL with ELM plus bougie (AOR = 2.8, 95% CI = 2.3 to 3.3). Subgroup analyses of HA-VL and SG-VL compared with any A-DL yielded similar results (AOR = 3.2, 95% CI = 2.6 to 3.0; and AOR = 2.4, 95% CI = 1.9 to 3.0, respectively). The propensity score-adjusted odds for first-attempt success with VL was also 2.8 (95% CI = 2.4 to 3.3). Fewer esophageal intubations were observed in the VL cohort (0.4% vs. 1.3%, AOR = 0.2, 95% CI = 0.1 to 0.5).

CONCLUSIONS

Video laryngoscopy used without any augmenting maneuver, device, or technique results in higher first-attempt success than does DL that is augmented by use of a bougie, ELM, ramping, or combinations thereof.

First-Pass Success Intubations Using Video Laryngoscopy Versus Direct Laryngoscopy: A Retrospective Prehospital Ambulance Service Study

OBJECTIVE

In emergency medicine, endotracheal intubation is the gold standard for airway management. First-pass intubation success is beneficial because it secures the patient airway more quickly and avoids complications associated with repeated attempts, such as bleeding and swelling of soft tissue. The key to first-pass success is the ability to visualize the laryngeal inlet. Visualization can be accomplished using traditional direct laryngoscopy or video laryngoscopy. The purpose of our study was to compare the rate of successful first-pass endotracheal intubations using a video laryngoscope with that using a direct visualization laryngoscope in a prehospital emergency setting.

METHODS

We retrospectively reviewed data that had been prospectively collected in our emergency department regarding patients who underwent endotracheal intubation performed by personnel from a single local ambulance service from January 1, 2014, through December 31, 2015.

RESULTS

One hundred eighty-one patients were intubated using video laryngoscopy and 115 using direct visualization laryngoscopy. The first-pass endotracheal intubation success rate using video laryngoscopy was 12.6% higher than with direct laryngoscopy.

CONCLUSION

This retrospective study shows that video laryngoscopy had a higher first-pass success rate than direct laryngoscopy. This is promising because decreasing failure rates provide better patient outcomes.

Video versus direct laryngoscopy on successful first-pass endotracheal intubation in ICU patients

BACKGROUND

Airway management in intensive care unit (ICU) patients is challenging. The aim of this study was to compare the rate of successful first-pass intubation in the ICU by using the direct laryngoscopy (DL) and that by using the video laryngoscopy (VL).

METHODS

A randomized, non-blinded trial comparing first-pass success rate of intubation between VL and DL was performed. Patients were recruited in the period from August 2014 to August 2016. All physicians working at ICU received hands-on training in the use of the video and direct laryngoscope. The primary outcome measure was the first-pass intubation success.

RESULTS

A total of 163 ICU patients underwent intubation during the study period (81 patients in VL group and 82 in DL group). The rate of successful first-pass intubation was not significantly different between the VL and the DL group (67.9% vs. 69.5%, P=0.824). Moreover, the overall intubation success and total number of attempts to achieve intubation success did not differ between the two groups. In patients with successful first-pass intubation, the median duration of the intubation procedure did not differ between the two groups. The Cormack-Lehane grades and the percentage of glottic opening score were similar, and no significant differences were found between the two groups. There were no statistical differences between the VL and the DL group in intubation complications (all P>0.05).

CONCLUSION

Among ICU patients requiring intubation, there was no significant difference in the rate of successful first-pass intubation between VL and DL.

Guidelines for the management of tracheal intubation in critically ill adults

These guidelines describe a comprehensive strategy to optimize oxygenation, airway management, and tracheal intubation in critically ill patients, in all hospital locations. They are a direct response to the 4^th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, which highlighted deficient management of these extremely vulnerable patients leading to major complications and avoidable deaths. They are founded on robust evidence where available, supplemented by expert consensus opinion where it is not. These guidelines recognize that improved outcomes of emergency airway management require closer attention to human factors, rather than simply introduction of new devices or improved technical proficiency. They stress the role of the airway team, a shared mental model, planning, and communication throughout airway management. The primacy of oxygenation including pre- and peroxygenation is emphasized. A modified rapid sequence approach is recommended. Optimal management is presented in an algorithm that combines Plans B and C, incorporating elements of the Vortex approach. To avoid delays and task fixation, the importance of limiting procedural attempts, promptly recognizing failure, and transitioning to the next algorithm step are emphasized. The guidelines recommend early use of a videolaryngoscope, with a screen visible to all, and second generation supraglottic airways for airway rescue. Recommendations for emergency front of neck airway are for a scalpel-bougie-tube technique while acknowledging the value of other techniques performed by trained experts. As most critical care airway catastrophes occur after intubation, from dislodged or blocked tubes, essential methods to avoid these complications are also emphasized.

Evaluation of the McGrath MAC and Macintosh laryngoscope for tracheal intubation in 2000 patients undergoing general anaesthesia: the randomised multicentre EMMA trial study protocol

INTRODUCTION

The direct laryngoscopy technique using a Macintosh blade is the first choice globally for most anaesthetists. In case of an unanticipated difficult airway, the complication rate increases with the number of intubation attempts. Recently, McGrath MAC (McGrath) video laryngoscopy has become a widely accepted method for securing an airway by tracheal intubation because it allows the visualisation of the glottis without a direct line of sight. Several studies and case reports have highlighted the benefit of the video laryngoscope in the visualisation of the glottis and found it to be superior in difficult intubation situations. The aim of this study was to compare the first-pass intubation success rate using the (McGrath) video laryngoscope compared with conventional direct laryngoscopy in surgical patients.

METHODS AND ANALYSIS

The EMMA trial is a multicentre, open-label, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath video laryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of successful first-pass intubation is 95% in the McGrath group and 90% in the Macintosh group. Each group must include a total of 1000 patients to achieve 96% power for detecting a difference at the 5% significance level. Successful intubation with the first attempt is the primary endpoint. The secondary endpoints are the time to intubation, attempts for successful intubation, the necessity of alternatives, visualisation of the glottis using the Cormack & Lehane score and percentage of glottic opening score and definite complications.

ETHICS AND DISSEMINATION

The project was approved by the local ethics committee of the Medical Association of the Rhineland Palatine state and Westphalia-Lippe. The results of this study will be made available in the form of manuscripts for publication and presentations at national and international meetings.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT 02611986; pre-results.

Randomized Trial of Video Laryngoscopy for Endotracheal Intubation of Critically Ill Adults

OBJECTIVE

To evaluate the effect of video laryngoscopy on the rate of endotracheal intubation on first laryngoscopy attempt among critically ill adults.

DESIGN

A randomized, parallel-group, pragmatic trial of video compared with direct laryngoscopy for 150 adults undergoing endotracheal intubation by Pulmonary and Critical Care Medicine fellows.

SETTING

Medical ICU in a tertiary, academic medical center.

PATIENTS

Critically ill patients 18 years old or older.

INTERVENTIONS

Patients were randomized 1:1 to video or direct laryngoscopy for the first attempt at endotracheal intubation.

MEASUREMENTS AND MAIN RESULTS

Patients assigned to video (n = 74) and direct (n = 76) laryngoscopy were similar at baseline. Despite better glottic visualization with video laryngoscopy, there was no difference in the primary outcome of intubation on the first laryngoscopy attempt (video 68.9% vs direct 65.8%; p = 0.68) in unadjusted analyses or after adjustment for the operator's previous experience with the assigned device (odds ratio for video laryngoscopy on intubation on first attempt 2.02; 95% CI, 0.82-5.02, p = 0.12). Secondary outcomes of time to intubation, lowest arterial oxygen saturation, complications, and in-hospital mortality were not different between video and direct laryngoscopy.

CONCLUSIONS

In critically ill adults undergoing endotracheal intubation, video laryngoscopy improves glottic visualization but does not appear to increase procedural success or decrease complications.

Comparison of the ETView Single Lumen and Macintosh laryngoscopes for endotracheal intubation in an airway manikin with immobilized cervical spine by novice paramedics: A randomized crossover manikin trial

CONTEXT

Management of the airway of a trauma victim is considered challenging. Various approaches have been described to achieve airway control in this setup; many of them include video-assited viewing of the larynx during intubation. ETView Single Lumen (SL) is a novice single-use endotracheal tube equiped with a video camera and a light source at its distal tip. Its use was previously described in seeral clinical and training setups.

OBJECTIVE

The aim was to evaluate the efficacy of the VivaSight SL compared with classic direct laryngoscopy performed with a Macintosh blade in a manikin-simulated trauma setup presenting various degrees of airway challenge when performed by inexperienced physicians.

DESIGN, SETTING, PARTICIPANTS

This was prospective, randomized, crossover, manikin trial. After short training on the ETView system, 67 novice paramedics attempted to perform oral intubation using both standard direct laryngoscopy (MAC group) and the VivaSight SL endotracheal tube (ETView group) in a randomized order on manikins in 3 increasingly more difficult scenarios (simple intubation, cervical spine manual stabilization, and with cervical collar in place).

OUTCOME MEASURE

Overall success rate, time to intubation, number of intubation attempts, laryngeal view grade, dental compression, and overall participant satisfaction were monitored.

RESULTS

Duration of intubation and number of attempts were significantly superior in the ETView group in the latter 2 more challenging scenarios. All other parameters showed superiority to the ETView group in all 3 scenarios.

CONCLUSION

The VivaSight SL system performed better in a complex scenario of airway management of a trauma victim in need for cervical spine stabilization performed by novice caregivers compared to standard direct laryngoscopy and should be considered in this clinical setup.

Changes in the first-pass success rate with the GlideScope video laryngoscope and direct laryngoscope: a ten-year observational study in two academic emergency departments

OBJECTIVE

The aim of this study was to assess the success rate of the GlideScope video laryngoscope (GVL) and direct laryngoscope (DL) over ten years in two academic emergency departments.

METHODS

We used adult intubation data using DL and GVL collected from airway management registries at two academic emergency departments. We analyzed changes in first-pass success (FPS) rate by device and operator training level. We conducted a multivariate logistic regression analysis to predict the FPS according to time period.

RESULTS

Over the study period (2006 to 2010, season I; 2013-2015, season II) the DL usage rate dropped from 91.6% to 45.0% while the GVL usage rate increased from 8.4% to 55.4%. The FPS rate using DL also declined from 90.8% in 2007 to 75.5% in 2015. On the other hand, the FPS rate using GVL increased from 87.8% to 95.2%. With DL, all operators' FPS rate declined by approximately 10% in season II compared to season I. The FPS rate with GVL was significantly higher in the providers of postgraduate year over 3 years (P=0.043). Multivariate logistic regression analysis revealed an adjusted odds ratio for GVL FPS of 0.799 during season I (P=0.274). However, the adjusted odds ratio for GVL FPS was 3.744 during season II (P<0.001).

CONCLUSION

We found that the FPS rates of GVL have slightly increased but DL's FPS rate has significantly decreased during the last ten years.

Telemedicine-Assisted Intubation in Rural Emergency Departments: A National Emergency Airway Registry Study

BACKGROUND

Intubation in rural emergency departments (EDs) is a high-risk procedure, often with little or no specialty support. Rural EDs are utilizing real-time telemedicine links, connecting providers to an ED physician who may provide clinical guidance.

INTRODUCTION

We endeavored to describe telemedicine-assisted intubation in rural EDs that are served by an ED telemedicine network.

MATERIALS AND METHODS

Prospective data were collected on all patients who had an intubation attempt while on the video telemedicine link from May 1, 2014 to April 30, 2015. We report demographic information, indication, methods, number of attempts, operator characteristics, telemedicine involvement/intervention, adverse events, and clinical outcome by using descriptive statistics.

RESULTS

Included were 206 intubations. The most common indication for intubation was respiratory failure. First-pass success rate (postactivation) was 71%, and 96% were eventually intubated. Most attempts (66%) used rapid-sequence intubation. Fifty-four percent of first attempts used video laryngoscopy (VL). Telemedicine providers intervened in 24%, 43%, and 55% of first-third attempts, respectively. First-pass success with VL and direct laryngoscopy was equivalent (70% vs. 71%, p = 0.802). Adverse events were reported in 49 cases (24%), which were most frequently hypoxemia.

DISCUSSION

The impact of telemedicine during emergency intubation is not defined. We showed a 71% first-pass rate post-telemedicine linkage (70% of cases had a previous attempt). Our ultimate success rate was 96%, similar to that in large-center studies. Telemedicine support may contribute to success.

CONCLUSIONS

Telemedicine-supported endotracheal intubation performed in rural hospitals is feasible, with good success rates. Future research is required to better define the impact of telemedicine providers on emergency airway management.

Device and Medication Preferences of Canadian Physicians for Emergent Endotracheal Intubation in Critically Ill Patients

OBJECTIVES

Various medications and devices are available for facilitation of emergent endotracheal intubations (EETIs). The objective of this study was to survey which medications and devices are being utilized for intubation by Canadian physicians.

METHODS

A clinical scenario-based survey was developed to determine which medications physicians would administer to facilitate EETI, their first choice of intubation device, and backup strategy should their first choice fail. The survey was distributed to Canadian emergency medicine (EM) and intensive care unit (ICU) physicians using web-based and postal methods. Physicians were asked questions based on three scenarios (trauma; pneumonia; heart failure) and responded using a 5-point scale ranging from "always" to "never" to capture usual practice.

RESULTS

The survey response rate was 50.2% (882/1,758). Most physicians indicated a Macintosh blade with direct laryngoscopy would "always/often" be their first choice of intubation device in the three scenarios (mean 85% [79%-89%]) followed by video laryngoscopy (mean 37% [30%-49%]). The most common backup device chosen was an extraglottic device (mean 59% [56%-60%]). The medications most physicians would "always/often" administer were fentanyl (mean 45% [42%-51%]) and etomidate (mean 38% [25%-50%]). EM physicians were more likely than ICU physicians to paralyze patients for EETI (adjusted odds ratio 3.40; 95% CI 2.90-4.00).

CONCLUSIONS

Most EM and ICU physicians utilize direct laryngoscopy with a Macintosh blade as a primary device for EETI and an extraglottic device as a backup strategy. This survey highlights variation in Canadian practice patterns for some aspects of intubation in critically ill patients.

Use-Dependent Curvature Changes in the GlideRite® Reusable Intubation Stylet

The Glidescope® is one of the most widely used video laryngoscopes in the market. It is often used with a purpose-built, reusable, "nonmalleable" stainless steel stylet, the GlideRite®. In this study, we investigated whether this stylet retains its original curvature with repeated use and sterilization. To evaluate the shape and curvature of the stylets, high-resolution digital photographs were made of 55 GlideRite stylets (5 new and 50 randomly selected from operating room stock) laid on a grid background and analyzed using Adobe Photoshop®. In a similar fashion, 1 new stylet was inserted into and removed 100 times from an endotracheal tube and photographed every 20 cycles to determine the impact of use on stylet shape. For the 5 new stylets, the handle-to-tip angle was very consistent (23.44° ± 1.04°). The stylets in clinical use varied widely in their configuration. For analysis, they were divided into 3 groups based on the handle-to-tip angle: ±1 SD of the new stylets, those with a shallower angle (straighter), and those with a steeper angle (more curved). The handle-to-tip angles were as follows: 23.07° ± 0.80° (±1 SD), 18.39° ± 2.59° (straighter), and 27.65° ± 2.73° (more curved). Analysis of variance showed that the new and ±1 SD groups were not significantly different, but both the straighter (P = 0.0002) and more curved (P = 0.0048) groups were significantly different from new. The repeated insertion and removal of a new stylet resulted in gradual straightening of the curve of the stylet from 22° at baseline to 19.2° after 100 insertion/removal cycles. Used GlideRite reusable stylets are not reliably equivalent to new ones in terms of their shape or curvature. Given that the repeated insertion and removal of a new stylet from an endotracheal tube resulted in their straightening, it is likely that clinical use has the same effect. Because many used stylets were actually more curved than the new ones, we hypothesize that practitioners likely bend the nonmalleable stylets to improve clinical utility, but often fail to recapture the manufacturer-intended curve. The clinical relevance of the change in shape of the GlideRite stylet remains to be determined; it is that possible intubation may be more difficult than expected compared with the use of new stylets.

Comparison of the C-MAC video laryngoscope to the Macintosh laryngoscope for intubation of blunt trauma patients in the ED

Objectives

We aimed to compare the performance of the C-MAC video laryngoscope (C-MAC) to the Macintosh laryngoscope for intubation of blunt trauma patients in the ED.

Material and methods

This was a prospective randomized study. The primary outcome measure is overall successful intubation. Secondary outcome measures are first attempt successful intubation, Cormack–Lehane (CL) grade, and indicators of the reasons for unsuccessful intubation at the first attempt with each device. Adult patients who suffered from blunt trauma and required intubation were randomized to video laryngoscopy with C-MAC device or direct laryngoscopy (DL).

Results

During a 17-month period, a total of 150 trauma intubations were performed using a C-MAC and DL. Baseline characteristics of patients were similar between the C-MAC and DL group. Overall success for the C-MAC was 69/75 (92%, 95% CI 0.83 to 0.96) while for the DL it was 72/75 (96%, 95% CI 0.88 to 0.98). First attempt success for the C-MAC was 47/75 (62.7%, 95% CI 0.51 to 0.72) while for the DL it was 44/75 patients (58.7%, 95% CI 0.47 to 0.69). The mean time to achieve successful intubation was 33.4 ± 2.5 s for the C-MAC versus 42.4 ± 5.1 s for the DL (p = 0.93). There was a statistically significant difference between the DL and C-MAC in terms of visualizing the glottic opening and esophageal intubation in favor of the C-MAC (p = 0.002 and p = 0.013 respectively).

Discussion and conclusion

The overall success rates were similar. The C-MAC demonstrated improved glottic view and decrease in esophageal intubation rate.

The use of a video laryngoscope by emergency medicine residents is associated with a reduction in esophageal intubations in the emergency department

OBJECTIVES

The purpose of this investigation was to compare the incidence of esophageal intubations (EIs) when emergency medicine (EM) residents used a direct laryngoscope (DL) versus a video laryngoscope (VL) for intubation attempts in the emergency department (ED).

METHODS

Prospectively collected continuous quality improvement data on tracheal intubations performed by EM residents in an academic ED over a 6-year period were retrospectively analyzed. Following each intubation, EM residents completed a data form with patient, intubation, and operator characteristics. Data collected included the method of intubation, drugs used, device(s) used, number of attempts, outcome of each attempt, occurrence of EIs, and occurrence of adverse events (hypoxemia, aspiration, dysrhythmia, hypotension, and cardiac arrest). The incidence of EI was compared between intubation attempts with a DL and with a VL (GlideScope(®) or C-MAC(®) ). Propensity score matching and conditional logistic regression were used to analyze the association between the intubation device (DL vs. VL) and EI.

RESULTS

Over the 6-year period, 2,677 patients underwent 3,425 intubation attempts by EM residents with a DL or a VL. A DL was used in 1,530 attempts (44.7%) and a VL was used in 1,895 attempts (55.3%). There were 96 recognized EIs (2.8%). The incidence of EI when using a DL was 78 of 1,530 attempts (5.1%; 95% confidence interval [CI] = 4.1% to 6.3%) and when using a VL was 18 of 1,895 attempts (1.0%; 95% CI = 0.6% to 1.5%). Based on the propensity score matched analysis, the odds ratio for the occurrence of an EI for DL versus VL was 6.9 (95% CI = 3.3 to 14.4). Patients who had inadvertent EIs had a higher incidence of adverse events (49.5%; 95% CI = 38.9% to 60.0%) than patients in which EI did not occur (19.8%; 95% CI = 18.3% to 21.4%).

CONCLUSIONS

The use of a VL by EM residents during an intubation attempt in the ED was associated with significantly fewer EIs compared to when a DL was used. Patients who had inadvertent EIs had significantly more adverse events than those who did not have EIs. EM residency training programs should consider using VLs for ED intubations to maximize patient safety when EM residents are performing intubation.