Learning curves for direct laryngoscopy and glidescope® video laryngoscopy in an emergency medicine residency

Introduction: Our objective is to evaluate the resident learning curves for direct laryngoscopy (DL) and GlideScope® video laryngoscopy (GVL) over the course of an emergency medicine (EM) residency training program.

Methods: This was an analysis of intubations performed in the emergency department (ED) by EM residents over a seven-year period from July 1, 2007 to June 30, 2014 at an academic ED with 70,000 annual visits. After EM residents perform an intubation in the ED they complete a continuous quality improvement (CQI) form. Data collected includes patient demographics, operator post-graduate year (PGY), difficult airway characteristics (DACs), method of intubation, device used for intubation and outcome of each attempt. We included in this analysis only adult intubations performed by EM residents using a DL or a standard reusable GVL. The primary outcome was first pass success, defined as a successful intubation with a single laryngoscope insertion. First pass success was evaluated for each PGY of training for DL and GVL. Logistic mixed-effects models were constructed for each device to determine the effect of PGY level on first pass success, after adjusting for important confounders.

Results: Over the seven-year period, the DL was used as the initial device on 1,035 patients and the GVL was used as the initial device on 578 patients by EM residents. When using the DL the first past success of PGY-1 residents was 69.9% (160/229; 95% CI 63.5%-75.7%), of PGY-2 residents was 71.7% (274/382; 95% CI 66.9%-76.2%), and of PGY-3 residents was 72.9% (309/424; 95% CI 68.4%-77.1%). When using the GVL the first pass success of PGY-1 residents was 74.4% (87/117; 95% CI 65.5%-82.0%), of PGY-2 residents was 83.6% (194/232; 95% CI 76.7%-87.7%), and of PGY-3 residents was 90.0% (206/229; 95% CI 85.3%-93.5%). In the mixed-effects model for DL, first pass success for PGY-2 and PGY-3 residents did not improve compared to PGY-1 residents (PGY-2 aOR 1.3, 95% CI 0.9-1.9; p-value 0.236) (PGY-3 aOR 1.5, 95% CI 1.0-2.2, p-value 0.067). However, in the model for GVL, first pass success for PGY-2 and PGY-3 residents improved compared to PGY-1 residents (PGY-2 aOR 2.1, 95% CI 1.1-3.8, p-value 0.021) (PGY-3 aOR 4.1, 95% CI 2.1-8.0, p< 0.001).

Conclusion: Over the course of residency training there was no significant improvement in EM resident first pass success with the DL, but substantial improvement with the GVL.