Depth of Anesthesia Monitoring: A Survey of Attitudes and Usage Patterns Among Australian Anesthesiologists

BACKGROUND: Utility of depth of anesthesia (DoA) monitors is contentious as evidence appears ambiguous regarding their clinical effectiveness and exact role. We conducted a survey of Australian anesthesiologists to determine their attitudes toward, and how and why they use, DoA monitors. METHODS: A random sample of 963 anesthesiologists was invited to participate in an anonymous online survey. RESULTS: The overall response rate was 30% (289 respondents). Twenty-nine percent (95% confidence interval, 24%-34%) of respondents thought DoA monitoring was indicated in all cases under relaxant general anesthesia. During total IV anesthesia with muscle relaxants, 74% of respondents (69%-79%) opined that DoA monitoring should be mandatory. DoA usage was never used by 5% of respondents (3%-8%), used in less than one-third of cases by 66% (6196-72%), and in more than one-third of cases by 29% (24%-35%). Belief in the usefulness of DoA monitoring for prevention of awareness was strongly associated with higher usage (P < 0.0001, Pearson correlation 0.32). Anesthesiologists were more influenced by higher DoA numbers than lower ones. in comparison with end-tidal anesthetic concentration monitoring, 30% (25%-35%) of respondents felt that DoA monitoring was more effective for prevention of intraoperative awareness. Thirty percent (25%-36%) of respondents reported having a previous case of awareness. CONCLUSIONS: The relatively frequent use of DoA monitoring contrasts with patterns in the UK, suggesting greater acceptance by Australian anesthesiologists. "Awareness prevention" rather than "recovery enhancement" appears to be the primary driver in DoA monitoring use in Australia. Highly variable usage patterns of DoA monitoring in the context of the current body of evidence suggest the need for greater education on the appropriate use of these Monitors.