A measure of intraoperative attention to monitor displays

Vigilance is an important but difficult to measure attribute in anesthesia practitioners. We present a modified standard method to assess intraoperative vigilance toward electronic data displays. The response time to detect a simulated abnormal value on the physiologic monitor was measured. Eight anesthesia residents were studied during 60 surgical procedures. Responses to 439 abnormal values were analyzed. The average response time was 61 +/- 61 s (mean +/- SD), and 56% of the detections were made within 60 s. However, 16% of the abnormal values were undetected during the 5 min that they were displayed. Response times and the rate of missed events were greater during induction of anesthesia (a time of high workload) than during the maintenance or emergence phases of anesthesia. Response times were shorter during procedures on ASA 1 patients than on ASA 3 patients. The results suggest that anesthesiologists usually quickly detect abnormal values on physiologic monitors and that less attention is devoted to monitors during periods of high workload.