Cross-over study of novice intubators performing endotracheal intubation in an upright versus supine position

An investigation into emergency medicine resident cricothyrotomy competency: Is three the magic number?

Objectives

Cricothyrotomy is a high-stakes emergency procedure. Because the procedure is rare, simulation is often used to train residents. The Accreditation Council for Graduate Medical Education (ACGME) requires performance of three cricothyrotomies during residency, but the optimal number of training repetitions is unknown. Additional repetitions beyond three could increase proficiency, though it is unknown whether there is a threshold beyond which there is no benefit to additional repetition. The objective of this study was to establish a minimum number of simulated cricothyrotomy attempts beyond which additional attempts did not increase proficiency.

Methods

This was a prospective, observational study conducted over 3 years at the simulation center of an academic emergency medicine residency program. Participants were residents participating in a cricothyrotomy training as part of a longitudinal airway curriculum course. The primary outcome was time to successful completion of the procedure as first-year residents. Secondary outcomes included time to completion as second- and third-year residents. Procedure times were plotted as a function of attempt number. Data were analyzed using descriptive statistics, repeated-measures analysis of variance, and correlation analysis. Preprocedure surveys collected further data regarding procedure experience, confidence, and comfort.

Results

Sixty-nine first-year residents participated in the study. Steady improvement in time to completion was seen through the first six attempts (from a mean of 75 to 41 sec), after which no further significant improvement was found. Second- and third-year residents initially demonstrated slower performance than first-year residents but rapidly improved to surpass their first-year performance. Resident mean times at five attempts were faster with each year of residency (first-year 48 sec, second-year 30 sec, third-year 24 sec). There was no statistically significant correlation between confidence and time to complete the procedure.

Conclusions

Additional repetition beyond the ACGME-endorsed three cricothyrotomy attempts may help increase proficiency. Periodic retraining may be important to maintain skills.

Effect of inclined positioning on first-pass success during endotracheal intubation: a systematic review and meta-analysis

BACKGROUND

Endotracheal intubation is a high-risk procedure. Optimisation of all aspects of the procedure, including patient positioning, is important to facilitate success and minimise complications. The objective of this systematic review was to determine the association between inclined patient positioning and first-pass success and other clinically important outcomes among patients undergoing endotracheal intubation.

METHODS

A search of PubMed, CINAHL, SCOPUS, EMBASE and Cochrane, from inception through October 2020 was conducted. Studies were assessed independently by two authors to determine eligibility for inclusion. Included studies were any randomised or observational study that compared supine to inclined patient positioning for endotracheal intubation and assessed one of our predefined outcomes. Simulation studies were excluded. Study results were meta-analysed using a random effects model. The quality of the evidence for outcomes of interest was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS

A total of 5113 studies were identified, of which 10 studies representing 18 371 intubations were included for meta-analysis. There was no statistically significant difference in the primary outcome of first-pass success rate (relative risk 1.02, 95% CI 0.98 to 1.05) or secondary outcomes of oesophageal intubation, glottic view, hypotension, hypoxaemia, mortality or peri-intubation arrest. Likewise, there were no statistically significant differences in any of the outcomes in predefined subgroup analyses of randomised controlled trials, intubations in acute settings or intubations performed with >45 degrees of incline. Overall quality of evidence was rated as low or very low for most outcomes.

CONCLUSIONS

This systematic review and meta-analysis found no evidence of benefit or harm with inclined versus supine patient positioning during endotracheal intubation in any setting.

Effect of an Aerosol Box on Intubation in Simulated Emergency Department Airways: A Randomized Crossover Study

INTRODUCTION

The use of transparent plastic aerosol boxes as protective barriers during endotracheal intubation has been advocated during the severe acute respiratory syndrome coronavirus 2 pandemic. There is evidence of worldwide distribution of such devices, but some experts have warned of possible negative impacts of their use. The objective of this study was to measure the effect of an aerosol box on intubation performance across a variety of simulated difficult airway scenarios in the emergency department.

METHODS

This was a randomized, crossover design study. Participants were randomized to intubate one of five airway scenarios with and without an aerosol box in place, with randomization of intubation sequence. The primary outcome was time to intubation. Secondary outcomes included number of intubation attempts, Cormack-Lehane view, percent of glottic opening, and resident physician perception of intubation difficulty.

RESULTS

Forty-eight residents performed 96 intubations. Time to intubation was significantly longer with box use than without (mean 17 seconds [range 6-68 seconds] vs mean 10 seconds [range 5-40 seconds], p <0.001). Participants perceived intubation as being significantly more difficult with the aerosol box. There were no significant differences in the number of attempts or quality of view obtained.

CONCLUSION

Use of an aerosol box during difficult endotracheal intubation increases the time to intubation and perceived difficulty across a range of simulated ED patients.

Endotracheal intubation in a ramped versus supine position in the emergency department: A randomised crossover manikin study

Background:

Performing endotracheal intubation by placing patients in a ramped position has been shown to improve the ease of intubation and to reduce complications. The above findings, however, were only established in the operation theatre and intensive care settings.

Objective:

In order to establish the findings in the setting of the emergency department, we attempt to compare the ramped versus supine positions in normal and difficult airway scenarios.

Methods:

Medical doctors practicing at a local Accident and Emergency Department were recruited into a crossover randomised study. They were asked to perform intubations on a manikin in four scenarios. The manikin was put in a ramp or supine position. In addition, the manikin settings were adjusted to normal and difficult airways.

Results:

A total of 39 Accident and Emergency Department doctors were recruited. There was no statistically significant difference in the first-attempt success rates using the ramped position compared to supine position in either airway scenario (100% vs. 97.4%, P = 1 in normal airway, 79.5% vs. 74.4%, P = 0.789 in difficult airway). The mean intubation time in difficult airway setting was shorter when the manikin was put into ramped position (28.3 s vs. 38.4 s, P = 0.134). The ramped position improved the glottic view in the difficult airway setting ( P = 0.017). More intubators preferred to place the manikin into a ramped position during difficult airway setting (67%, P = 0.007). Experienced male intubators performed better in normal airway scenarios, whereas Accident and Emergency Department fellows performed better in difficult airway scenarios.

Conclusion:

The ramped position improves glottic view and operator ease when intubating a simulated difficult airway.

Impact of bed angle and height on intubation success during simulated endotracheal intubation in the ramped position

OBJECTIVE

The ramped position is often used during endotracheal intubation to improve oxygenation, improve laryngeal views, and reduce airway complications. We sought to compare the impact of ramp angle and bed height on intubation outcomes during simulated endotracheal intubation.

METHODS

We enrolled emergency medicine residents and fourth-year medical students to perform simulated direct laryngoscopy and endotracheal intubation in random order with the mannequin in the following combinations of ramp angles and bed heights; ramp angles of 25° and 45° at bed heights including knee, mid-thigh, umbilicus, xiphoid, and nipple/intermammary fold. Our primary outcome was the reported percentage of glottic opening (POGO) score. Secondary outcomes included number of laryngoscopy attempts and intubation time.

RESULTS

We enrolled 25 participants. There was no difference in reported POGO scores at 25° between bed heights, but at 45°, the umbilicus bed height had an improved reported POGO score (20; 95% confidence interval [CI] 7-33, P < 0.01) relative to xyphoid. The nipple/inframammary fold height required longer intubation times in seconds (mean difference [MD] 95% CI) at 25°, (MD, 23.9 [4.6-37.6], P < 0.01) and more laryngoscopy attempts at 45° (MD, 0.48 [0.16-0.79], P < 0.01) relative to xyphoid. There was no difference in laryngoscopy attempts and video POGO between 25° and 45° at all bed heights, but reported POGO at the umbilicus position was better at 25° than 45° (12 [1-23], P = 0.03).

CONCLUSION

The umbilicus bed height resulted in the highest reported POGO at 45°. Nipple/inframammary fold height resulted in worse intubating conditions.