Abstract

Background and Objective: Postoperative delirium (POD) is a common complication of surgery, associated with significant morbidity and additional health care costs. Postoperative cognitive dysfunction (POCD) overlaps with postoperative delirium, but is considered to occur in the months following hospital discharge. The primary aim of this narrative review was to assess the effect of the use of depth of anesthesia (DoA) monitoring on the incidence of postoperative delirium. Secondary aims were to examine the effect of using DoA monitoring on postoperative cognitive dysfunction and the total dosage of anesthetics used.

Methods: An extensive search of PubMed and Embase databases was conducted until April 2025. Inclusion criteria were randomized controlled trials and articles published in English, and studies including adult patients under general anesthesia, where anesthetics were titrated using a depth of anesthesia monitor, to determine the incidence of POD or POCD. The quality of relevant articles was assessed using the Cochrane risk-of-bias tool.

Results: After full-text evaluation and quality assessment, ten articles were included in this narrative review. Six out of eight articles found a significant decline in POD when using a depth of anesthesia monitor. In comparison, only one of five studies found a significant decline in POCD. Seven study groups concluded that using a DoA monitoring system led to a decrease in the total dose of anesthetic administered.

Conclusion: Based on the reviewed literature, there may be a beneficial effect on the incidence of POD when a DoA monitor is used during general anesthesia. The effect on POCD seems to be much less significant. DoA monitoring also seems to be useful in lowering anesthetic dosages. However, this subject needs further study in large-scale prospective studies.