Retrospective analysis of cases of intraoperative awareness in a large multi-hospital health system reported in the early postoperative period

Abstract

Background: Awareness with recall under general anesthesia remains a rare but important issue that warrants further study. Methods: We present a series of seven cases of awareness that were identified from provider-reported adverse event data from the electronic anesthesia records of 647,000 general anesthetics. Results: The low number of identified cases suggests an under-reporting bias. Themes that emerge from this small series can serve as important reminders to anesthesia providers to ensure delivery of an adequate anesthetic for each patient. Commonalities between a majority of our identified anesthetic awareness cases include: obesity, use of total intravenous anesthesia, use of neuromuscular blockade, and either a lack of processed electroencephalogram (EEG) monitoring or documented high depth of consciousness index values. An interesting phenomenon was observed in one case, where adequately-dosed anesthesia was delivered without technical issue, processed EEG monitoring was employed, and the index value suggested an adequate depth of consciousness throughout the case. Conclusions: Provider-reported adverse event data in the immediate post-operative period are likely insensitive for detecting cases of intraoperative awareness. Though causation cannot firmly be established from our data, themes identified in this series of cases of awareness with recall under general anesthesia provide important reminders for anesthesia providers to maintain vigilance in monitoring depth and dose of anesthesia, particularly with total intravenous anesthesia.

Advanced endoscopic gastrointestinal techniques for the bariatric patient: implications for the anesthesia provider

“…The excess adipose tissue, higher circulating blood volume, and elevation in cardiac output results in changes to the volume of distribution, protein binding and drug elimination of most drugs, making safe and effective dosing of medications challenging [19]. For example, some studies have shown evidence of an increased risk for intraoperative awareness in obese patients [20]. Yet at the same time, other studies have shown that obese patients are prone to anesthetic overdosage leading to a higher degree of cardiovascular depression as compared to nonobese patients [21].…”

Postoperative recovery of patients with differential requirements for sevoflurane after abdominal surgery

“…[ 1 – 3 ] Low anaesthesia increases the risk of intraoperative awareness and adverse cardiovascular events, cerebrovascular events, and stress responses. [ 4 , 5 ] Therefore, it is crucial to identify a means to guide individually anaesthetized patients to improve postoperative recovery and avoid anaesthesia-related complications.…”