Battle of the Blades: Part 2

Battle of the Blades: Part 2 690 539 Richie Cunningham

Part 2: Who is the King of First-Pass Success?

            In our last post, we saw that the NEAR III data suggested video laryngoscopy increases first pass success, although there are several caveats and limitations to this conclusion. To dig deeper, let’s take a look at a Cochrane Review published in 2016 comparing direct to video laryngoscopy. Here are the basics:1

  • Included 64 RCTs with 7044 patients
    • 61 in the OR
    • 1 in the ED
    • 1 in the ICU
    • 1 in out-of-hospital setting
  • Studies that allowed direct visualization with standard-geometry video laryngoscopes were excluded (this is important)
  • Outcomes:
    • VL showed decreased failed intubation, laryngeal/airway trauma and hoarseness
      • However, of the four VL devices studied, only the CMAC showed decreased failed intubation, while the McGrath Series 5, GlideScope and Pentax did not
    • There was no difference in first pass success, number of attempts, hypoxia, mortality, or sore throat

Similar to NEAR III, the CMAC seems to be the superior device in this study. Reduced failed intubation and trauma to the airway are certainly worthy end points, but for a myriad of other important outcomes there seems to be no difference. It also must be noted that the vast majority of these studies were done in the OR and performed by anesthesiologists so application to the ED or ICU setting is limited. Luckily, there is a 2018 meta analysis that also compares DL to VL, this time in the ED:

  • 5 RCTs with 1250 patients
    • 3 compared CMAC with direct laryngoscopy
    • 2 compared GlideScope with direct laryngoscopy
  • Outcomes:
    • No difference between first-pass success, overall success, time to intubation, and survival to discharge
    • Two studies reported incidence of esophageal intubation with significant decrease with video laryngoscopy (OR 0.09, NNT 16)
  • Caveats: All were study small studies and a high risk of bias was identified in all

Put together, it seems that video laryngoscopy offers some advantages; it would make sense that with the improved glottic exposure with the camera, tube delivery is more easily facilitated, leading to both decreased trauma to the airway and esophageal intubations. Plus, the Cochrane Review suggests that with decreased failed intubation, video laryngoscopy can be a useful “bail-out” device when direct laryngoscopy has failed. However it is hard to give a ringing endorsement to video laryngoscopy if it doesn’t lead to increased first-pass success, as there is a significant association with multiple intubation attempts and increasing complications.3

At this point, I hope you’re convinced that direct laryngoscopy is still a reliable and acceptable method of emergency intubation. One thing that I find is not often considered in the debate between VL and DL however, is if it is possible to master both methods (at least for the average emergency physician or intensivist). We’ll explore this subject next time.

Read Part 3 here.

Peer Reviewed by: Jon Kelley, DO, Brendan Tarzia, DO

References:

  1. Lewis SR, Butler AR, Parker J, Cook TM, Schofeld-Robinson OJ, Smith AF (2017) Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation: a Cochrane systematic review. Br J Anaesth 119:369–383
  2. Bhattacharjee S, Maitra S, Baidya DK. A comparison between video laryngoscopy and direct laryngoscopy for endotracheal intubation in the emergency department: A meta-analysis of randomized controlled trials. J Clin Anesth. 2018;47:21-26. doi:10.1016/j.jclinane.2018.03.006
  3. Bernhard M, Becker TK, Gries A, Knapp J, Wenzel V. The First Shot Is Often the Best Shot: First-Pass Intubation Success in Emergency Airway Management. Anesthesia and analgesia. 2015; 121(5):1389-93. PMID: 26484464