International Meeting on Medical Simulation Best Abstract Winner

Eye Tracking System Improves Evaluation of Performance during Simulated Anesthesia Events

Darin K. Via, MD; Richard Kyle, MS; Uniformed Services University, Bethesda, MD
Yan Xiao, PhD; Jacob Seagull, BS; Colin MacKenzie, MD; University of Maryland, Baltimore, MD

Introduction: High-fidelity patient simulation has been proposed as a potential testing and evaluation tool for competency in anesthesia. To determine decision-making and cognitive function, simulator participants are often asked to "think aloud". However, verbalizing during simulator use is artificial compared to real anesthetic events. We hypothesize that an eye tracking system (ASL Bedford, MA) allows decision-making performance to be evaluated during simulated esophageal intubation without verbalization.

Methods: Nine Anesthesiologists (6 Staff, 3 Residents) were presented a spontaneously ventilating patient on a MedSim-Eagle high fidelity simulator with an endotracheal tube in the esophagus. The scenario was a combative trauma patient who was intubated after several attempts just prior to arrival at the trauma center. The anesthesiologists' performance was evaluated in the detection of the esophageal intubation. The participants were not instructed nor discouraged to verbalize actions, and were graded with a + or - in 4 tasks to detect an esophageal intubation (Table 1.) Fog on exhalation and cuff expansion of the sternal notch were not measured secondary to limits of the simulator. Performance was evaluated by analyzing both a room view video tape with recorded verbalizations, and also an eye tracking view of the event.

Results: Table 1. lists the tasks detected as completed (+) or not (-) by both means of detection for each participant.

Chest Rise and Fall	1	2	3	4	5	6	7	8	9	Total
Room View with Audio	-	-	-	-	-	-	-	-	-	0
Eye Tracker	+	+	+	+	+	+	+	+	+	9
Breath Sounds
Room View With Audio	+	+	+	+	+	+	+	+	+	9
Eye Tracker	+	+	+	+	+	+	+	+	+	9
ETCO2
Room View With Audio	-	+	-	+	-	+	-	+	+	5
Eye Tracker	+	+	-	+	+	+	+	+	+	8
Direct Laryngoscopy
Room View with Audio	+	-	-	-	-	+	+	-	-	3
Eye Tracker	+	-	-	-	-	+	+	-	-	3

Discussion: The use of the eye tracker improved evaluation in two of the four tasks utilized to detect esophageal intubation (Chest rise and ETCO2). Lack of CO2 is the only reliable indicator of esophageal intubation. Failure to check the ETCO2 monitor is a significant error. In this scenario 75% of the subjects who did not verbalize checking ETCO2, clearly did so as documented by eye tracking data. Eye tracking capabilities improves the ability of observers to evaluate performance tasks in simulated esophageal intubation.
Funded by the National Patient Safety Foundation