Direct versus Video Laryngoscopy during Simulated Mechanical Chest Compressions: A Randomized Crossover Trial.

Abstract

Sir, Mechanical compression devices are often utilized for cardiopulmonary resuscitation (mCPR) in the emergency department (ED). We conducted an investigation to evaluate the time to intubation, operator confidence, and success rates of endotracheal intubation with video laryngoscopy (VL) versus direct laryngoscopy (DL) during simulated mCPR. This was a prospective, randomized crossover trial. Thirty consenting emergency physicians were surveyed about experience/technique preferences, and then performed intubations on a moderately difficult airway and adult Manikin during simulated mCPR (LUCAS 3.0) at 100 compressions/min. Technique order was randomized. Intubation time defined as blade pick up until the tube cuff inflated. Participants rated success confidence on a 5-point scale (high = 5) and provided the Cormack/Lehane grade (difficult = 3 or 4). The scenario was repeated with the alternate technique. The categorical variables analyzed by the Chi-square and continuous variables by t-tests. Multivariate logistic regression was performed to control for confounding. There were 30 participants: 73% with 1–5 years of experience, 40% with >100 prior intubations, 73% utilized mac 4 direct blade, and 60% prefer VL during cardiopulmonary resuscitation (CPR). Participants had first pass intubation success for all but one of the attempts with both modalities (NS). Participants more often expressed “high confidence” that intubation was successful for direct 60% versus video 77% (P = 0.2), but they more often rated the airway “difficult” for direct (40% vs. 10%; P = 0.01). Within bivariate analysis, mean time difference to intubate was less for DL versus VL (−6.8 s; P = 0.02). There were no significant associations between time differences to intubate for the following variables: experience (P = 0.6), >100 prior intubations (P = 0.8), blade size (P = 0.3), preferred technique (P = 0.8), high confidence successful DL (P = 0.5), high confidence successful VL (P = 0.7), rating of difficult view DL (P = 0.8), and rating of difficult view VL (P = 0.9). In the multivariate logistic regression with time difference as the dependent variable, there were no statistically significant independent variables. Several prior investigators have reported the success rates of endotracheal intubation with and without chest compressions.[1–5] Han etal. described that VL was superior to DL in simulated CPR settings and that interruption of chest compressions was seemingly unnecessary.[1,3] However, within our literature search, we did not find earlier studies comparing VL versus DL mCPR. In contrast to the findings of Han etal., we observed a lower mean time difference to intubation for DL versus VL during simulated mCPR in our current study, although such differences are unlikely clinically meaningful. On the other hand, participants in our study group were more confident that intubation was successful when using VL. The limitations of our study include single center site, small sample size, participants had varying prior intubation experience, and the high-fidelity Manikin may not replicate all the aspects of difficult intubation in the setting of actual CPR in the ED. Future studies evaluating DL versus VL during mCPR should be conducted in the clinical setting. Research quality and ethics statement The authors followed applicable EQUATOR Network (http://www.equator-network.org/) guidelines, notably the CARE guideline, during the conduct of this report. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.