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.
© 2020 by the Society for Academic Emergency Medicine.