Journal Watch: Bougies for First-Pass Intubation Success

Reviewed This Month

Routine Use of a Bougie Improves First-Attempt Intubation Success in the Out-of-Hospital Setting

Authors: Latimer AJ, Harrington B, Counts CR, et al. 

Published in: Ann Emerg Med, 2021 Mar; 77(3): 296–304 

As we have seen in previous Journal Watches, it is important to evaluate interventions that have been shown effective in-hospital in the prehospital environment. Use of a bougie has been shown to improve first-attempt intubation success rates in the operating room and emergency department. While it has been shown bougies can be used safely by helicopter EMS, the study we review this month is the first to evaluate potential association between routine use of a bougie and first-attempt success during intubation performed by paramedics using direct laryngoscopy in the prehospital setting. The authors hypothesized bougie use would lead to higher rates of first-attempt intubation success without a significant change in complications. 

This was a “prospective, observational, intention-to-treat, pre-post analysis after a policy change”—in other words, the study was planned prior to data collection. The authors documented and described the impact of a new policy requiring paramedics to use a bougie for all initial intubation attempts. Intention-to-treat analyses compared the group that was supposed to receive the study intervention to the group that was not intended to receive it. Such groups would usually include both patients that have and have not received the intervention. In this study the authors compared first-attempt success among the patients treated in the period before bougies were required (control period) to those treated in the period after (bougie period), rather than directly comparing patients intubated using a bougie to those intubated without. 

The study took place in Seattle, where the Seattle Fire Department is the sole provider of EMS. Intubations there are performed with direct laryngoscopy and Macintosh blades. Any paramedics who are unable to perform at least 10 prehospital intubations annually are required to get to that number by intubating in the operating room. The study period was from July 1, 2015 to September 30, 2018. The control period was from January 1, 2015 to December 31, 2016, and the bougie period was from April 1, 2017 to September 30, 2018. There was a three-month training period (from January 1, 2017 to March 31, 2017) between the control period and the bougie period. Patients were excluded from the analysis if they were younger than 16, if a supraglottic device was used or cricothyrotomy without laryngoscopy was performed, or if the initial attempt was performed by a paramedic student. 

The primary outcome of interest was first-attempt intubation success, defined as successful placement of the endotracheal tube in the trachea on the first laryngoscopy attempt. A laryngoscopy attempt was defined as the laryngoscope blade passing the teeth, regardless of whether placement of the tube was attempted. Secondary outcomes included the overall number of attempts required for successful intubation and the presence of hypoxia during the intubation attempt. 

The authors performed logistic regression to evaluate the association between first-pass success and important independent variables including Cormack-Lehane grade, the patient’s position (flat or head-elevated), sex, age, whether it was a medical or trauma patient, if chest compressions were being performed, and the study periods.

Results 

There were 823 patients who had intubation attempted by 74 paramedics in the control period and 771 who had intubation attempted by 69 paramedics in the bougie period. The median number of attempts per paramedic was 16 and 15, respectively. There were 8.9% of patients who had a bougie used on the first attempt in the control period, and 81.3% who had a bougie used in the bougie period. About two-thirds of patients were male in both time periods, and the average age was similar (56 vs. 57). 

First-attempt success rates increased between the control and bougie periods from 70% to 77%. What’s more impressive is the higher first-attempt success was seen across all Cormack-Lehane grades, with a 5% increase (91% to 96%) for grade 1, 25% increase (60% to 85%) for grade 2, 23% increase (27% to 50%) for grade 3, and 8% increase (6% to 14%) for grade 4. The average number of attempts required for successful intubation also decreased from 1.4 per patient in the control period to 1.3 during the bougie period. After adjustment the logistic regression model revealed the bougie period was independently associated with higher first-attempt success (AOR 2.82; 95% CI: 1.96–4.01). Further, hypoxia at any point during the intubation declined from 30% to 19% between periods. 

Conclusion

This was an interesting study that supports the use of a bougie during intubation. As with all studies, there were some limitations. These included the evaluation of only one EMS system, which does not use Miller blades or video laryngoscopy. Also, since not all patients in the bougie period had a bougie used, this study was unable to fully assess the impact of routine bougie use. Nonetheless, this is an important addition to the literature. 

Read the entire study. Not only is it well written, but the authors included some easily interpretable and informative graphs as well as supplementary tables that help the reader compare both time periods. This is a wonderful example of a study design you may be able to replicate in your system.   

Antonio R. Fernandez, PhD, NRP, FAHA, is a research scientist at ESO and serves on the board of advisors of the Prehospital Care Research Forum at UCLA.