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.