Risk factors for delirium during anesthesia recovery: A meta-analysis

Objectives: Although several risk factors for delirium during recovery from anesthesia have been identified, many risk factors remain unknown. The present study aimed to identify risk factors for delirium during recovery from anesthesia by meta-analysis. Methods: A systematic literature search of PubMed and Web of Science databases was conducted from inception until October 2021 without language restriction. All studies assessing the risk factors for delirium during recovery from anesthesia were reviewed, and the Newcastle–Ottawa Scale was used to assess the quality of included studies. Data were pooled and a meta-analysis was completed using RevMan 5.4. Results: A total of 21750 patients from 19 cohort studies were analyzed. Male gender, high American Society of Anesthesiologists (ASA) classification, and longer operation time were identified as risk factors for delirium. However, a trend for increased delirium risk was observed for high body mass index(BMI), smoking, alcohol abuse, hypertension, and longer anesthesia time, but these did not reach statistical significance. Summary: Meta analysis results showed that male gender, high ASA classification, and longer operative time were risk factors for delirium. The evidence quality in this meta-analysis was moderate, according to NOS.