Manikin Laryngoscopy Motion as a Predictor of Patient Intubation Outcomes: A Prospective Observational Study

Abstract

The goal of this study was to determine whether motion parameters during laryngoscopy in a manikin differed with experienced operators versus novice trainees and whether motion measurements would predict trainee outcomes when intubating patients. Motion, force, and duration of laryngoscopy on a manikin were compared in two separate experiments between beginning anesthesiology residents (CA1) and anesthesiologists with more than 24 months of anesthesiology training (CA3 or attendings). In one experiment, CA1 residents were also evaluated for the percentage of their laryngoscope path that followed the route used by attending anesthesiologists. The residents were then observed for patient intubation outcomes for 4 weeks after manikin testing. The relationship between manikin test metrics and patient intubation outcomes was analyzed by multilevel modeling. CA1 residents positioned the laryngoscope blade farther right and with less lift than did experienced anesthesiologists. Endpoint position was 0.6 ± 0.3 cm left of midline for residents (n = 10) versus 2.7 ± 0.3 cm for advanced anesthesiologists (n = 8; P = .0003), and 15.6 ± 0.8 versus 17.7 ± 0.2 cm above the table surface, respectively (P = .033). On average, only 74 ± 6% of the CA1 laryngoscopy trajectory coincided with the Attending Route (P < .001 versus 100%). For each percentage point increase in Attending Route match, residents' odds of intubating a patient's trachea improved by a factor of 1.033 (95% confidence interval [CI] 1.007-1.059, P = .040), and their rate of failed laryngoscopy attempts decreased by a factor of 0.982 (0.969-0.996, P = .045). Laryngoscopy motion in manikins may predict which trainees can complete a patient intubation successfully in a few attempts. The assessment could help determine readiness for intubating patients with indirect supervision.