Abstract and Introduction
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.
Direct laryngoscopy (DL) has been the historical standard for airway management in the emergency department (ED); however, the use of video laryngoscopy (VL) has steadily risen over the past decade. As of 2012, about 55% of ED intubations were performed using DL, compared with 39% using VL. Prospective, single-center observational studies have demonstrated that VL improves glottic exposure and intubation success in ED and intensive care unit patients.[2–6] Furthermore, multiple studies have shown that VL use among emergency medicine residents has been associated with fewer adverse events, including esophageal intubations.[2–6] In spite of these promising results concerning VL, recent randomized trials in critical care patients and one meta-analysis of randomized trials with various patient types have not shown a clear benefit of one intubation method over the other. However, these studies do not fully represent ED populations since many studies excluded difficult airways and rapid sequence intubation or included primarily less experienced internal medicine trainees as intubators.[7–10]
One of the proposed advantages of VL is an absolute reduction in the number of failed intubations in patients with difficult airways, as suggested by multiple systematic reviews.[11–12] Difficult airways are more likely to require multiple attempts and are associated with an increased rate of complications and peri-intubation adverse events including esophageal intubation, airway trauma, and hypoxia.[13–17] Video laryngoscopy has become increasingly used in ED intubations, and variations in VL design (hyperangulated vs standard geometry blade shape) can affect the mechanics of intubation and may improve first-pass success (FPS).
Goals of This Investigation
Our primary goal in this study was to measure the rates of FPS comparing VL vs DL intubations in adult ED patients who had an anticipated or identified anatomically difficult airway. We also sought to answer the question of whether VL design (hyperangulated vs standard geometry) influenced FPS in these patients. Our secondary goal was to determine whether there were differences in peri-intubation adverse events between these two intubation methods.
Western J Emerg Med. 2022;23(5):706-715. © 2022 Western Journal of Emergency Medicine