Intraoperative Electroencephalogram Suppression Predicts Postoperative Delirium

Advances in awareness monitoring technologies

PURPOSE OF REVIEW

Initial studies suggested that the use of processed electroencephalogram technology could significantly decrease the incidence of unintended intraoperative awareness events during general anesthesia. Subsequent work has cast doubts on these findings. This review will examine the current state of awareness monitoring.

RECENT FINDINGS

Recently published randomized controlled trials examining the use of the bispectral index during general anesthesia have not been able to show superiority over other forms of monitoring depth of anesthesia, such as end-tidal anesthetic-agent concentration. Additionally, there is current interest in utilizing the unprocessed electroencephalogram to ascertain depth of anesthesia and recent studies have demonstrated its use in preventing postoperative delirium.

SUMMARY

Although awareness monitors such as the bispectral index monitor may have benefit in patients in whom volatile anesthetic agents must be minimized - such as in hemodynamically unstable patients, or patients undergoing total intravenous anesthesia - these monitors do not appear to be useful for all patients.

Current approach to diagnosis and treatment of delirium after cardiac surgery

Delirium after cardiac surgery remains a common occurrence that results in significant short- and long-term morbidity and mortality. It continues to be underdiagnosed given its complex presentation and multifactorial etiology; however, its prevalence is increasing given the aging cardiac surgical population. This review highlights the perioperative risk factors, tools to assist in diagnosing delirium, and current pharmacological and nonpharmacological therapy options.