Advanced auditory displays and head-mounted displays: advantages and disadvantages for monitoring by the distracted anesthesiologist.

BACKGROUND: In a full-scale anesthesia simulator study we examined the relative effectiveness of advanced auditory displays for respiratory and blood pressure monitoring and of head-mounted displays (HMDs) as supplements to standard intraoperative monitoring.
METHODS: Participants were 16 residents and attendings. While performing a reading-based distractor task, participants supervised the activities of a resident (an actor) who they were told was junior to them. If participants detected an event that could eventually harm the simulated patient, they told the resident, pressed a button on the computer screen, and/or informed a nearby experimenter. Participants completed four 22-min anesthesia scenarios. Displays were presented in a counterbalanced order that varied across participants and included: (1) Visual (visual monitor with variable-tone pulse oximetry), (2) HMD (Visual plus HMD), (3) Audio (Visual plus auditory displays for respiratory rate, tidal volume, end-tidal CO(2), and noninvasive arterial blood pressure), and (4) Both (Visual plus HMD plus Audio).
RESULTS: Participants detected significantly more events with Audio (mean = 90%, median = 100%, P < 0.02) and Both (mean = 92%, median = 100%, P < 0.05) but not with HMD (mean = 75%, median = 67%, ns) compared with the Visual condition (mean = 52%, median = 50%). For events detected, there was no difference in detection times across display conditions. Participants self-rated monitoring as easier in the HMD, Audio and Both conditions and their responding as faster in the HMD and Both conditions than in the Visual condition.
CONCLUSIONS: Advanced auditory displays help the distracted anesthesiologist maintain peripheral awareness of a simulated patient's status, whereas a HMD does not significantly improve performance. Further studies should test these findings in other intraoperative contexts.