These Are Not the DEVICE(s) You Are Looking For: October 2023 Annals of Emergency Medicine Journal Club.

Prekker ME, Driver BE, Trent SA, et al. Video versus direct laryngoscopy for tracheal intubation of critically ill adults. N Engl J Med. 2023;389:418-429. In critically ill patients undergoing tracheal intubation in the emergency department (ED) or ICU, does video laryngoscopy (VL), compared with direct laryngoscopy (DL), improve the rate of successful intubation on the first attempt? Design: Multicenter, randomized trial. Setting: Seven EDs and 10 ICUs in the United States. Population: Critically ill adults requiring tracheal intubation. Intervention: Video versus direct laryngoscopy. Primary Outcome: Successful intubation on the first attempt. Secondary Outcomes: Occurrence of severe complications during intubation, defined as severe hypoxemia, severe hypotension, new or increased vasopressor use, cardiac arrest, and/or death. Sponsors: Funded by the US Department of Defense. ClinicalTrials.gov: NCT05239195. Successful intubation on the first attempt occurred in 85.1% of patients in which VL was used compared with 70.8% of patients in which DL was used. This 14.3% absolute risk difference was statistically significant (95% confidence interval 9.9 to 18.7). The authors reported similar rates of severe complications (severe hypoxemia, severe hypotension, new or increased vasopressor use, cardiac arrest, or death) occurring in 21.4% of the video laryngoscope group and 20.9% of the direct laryngoscope group. The authors reported no difference in rates of esophageal intubation, injury to the teeth, or rate of aspiration. The authors concluded, in critically ill patients requiring tracheal intubation in the ED or ICU, the use of VL led to an improved first-pass success rate compared with DL. In a cohort of intubators primarily comprising US resident trainees, the use of VL demonstrated a moderate improvement in successful intubation on the first attempt. The generalizability of these observations to intubation success in experienced clinicians is not described. In the greater context of airway trials, it remains clear that VL is an effective tool for safe airway management. However, these findings do not specifically inform how DL is incorporated into practice and training, considering the necessity of acquiring multiple airway management techniques during training and ongoing skills maintenance. 1.Describe external validity and how the above factors might affect this trial’s external validity. The external validity of a trial refers to the generalizability or applicability of the results to a larger population.1Sedgwick P. Internal and external validity.BMJ. 2010; 340: c1705Crossref Scopus (0) Google Scholar As such, the results are only externally valid if the population investigated are representative of an additional population of interest. The DEVICE trial examined a narrow population of intubators performing airway management in a population of critically ill adults. In total, 74.8% of the intubators were either residents or fellows with a median number of 50 prior intubations. Consequently, the findings of this trial may not apply to clinicians with more airway experience. Furthermore, only 4.8% performed the majority of their prior intubations using DL. As such, the reported favoring of a device that the operators historically used heavily is foreseeable and potentially misleading. An externally valid conclusion from this investigation is trainees with a majority VL experience are likely to have higher first pass success (FPS) rates with VL.2.Given the question regarding the external validity of this trial, how should we interpret its results? The most straightforward interpretation of these results is novice intubators will increase their rate of FPS when using VL for emergency tracheal intubation. This is likely due to the fact successful DL requires a more nuanced and developed skill set than its video counterpart. Figure S7 in the supplemental appendix examines the FPS rate based on the operator’s prior experience with both video and direct laryngoscope. The heatmap indicates that as the operator’s prior experience with DL increased, the advantages of VL disappeared. Furthermore, the group of operators who saw the most benefit of VL were those having very little overall experience with either VL or DL. This suggests the skills required to become competent with DL require more exposure than those required for VL. These results suggest our trainees are in dire need of more training using DL. Furthermore, pitting VL and DL in a duel for superiority is in itself a false dichotomy. Both laryngoscopes are tools used during tracheal intubation. Both provide solutions to problems potentially encountered during intubation attempts; conversely, both have their limitations. The same could be said for subtypes of both video and direct laryngoscope blades. For example, hyperangulated versus standard geometry video laryngoscope blades each offer several advantages the other does not. Both devices solve specific problems that may be encountered in everyday airway management. Airway operators should be fluent in a number of techniques providing solutions to the common difficulties encountered during airway management. If we concern ourselves with only short-term success, it is easy to mistake the results of the DEVICE trial as simply showing the superiority of VL. In reality, these results demonstrate more experience is required to become competent with direct laryngoscopes and illustrates the lack of said competency in our trainees. In fact, one could argue this study suggests trainees require more, not less, frequent use of direct laryngoscopes as their primary airway tool.