Effectiveness of Non-Pharmacological Interventions for the Prevention of Postoperative Delirium in Critically Ill Adult Patients: A Systematic Review and Meta-Analysis

Abstract

Background/Objectives: Postoperative delirium is a frequent and clinically relevant complication among adult patients admitted to intensive care units (ICUs) following major surgery. It is associated with increased morbidity, prolonged hospitalization, functional decline, and greater healthcare burden. Although non-pharmacological interventions are widely recommended for delirium prevention, evidence regarding their effectiveness in postoperative critically ill adults remains heterogeneous. This systematic review aimed to evaluate the effectiveness of non-pharmacological interventions in preventing postoperative delirium in adult ICU patients. Methods: This systematic review was conducted according to PRISMA 2020 guidelines. Searches were performed in PubMed/MEDLINE, Embase, CINAHL, Cochrane CENTRAL, Web of Science, Scopus, LILACS, and Google Scholar. Eligible studies included randomized controlled trials, quasi-experimental studies, and comparative studies evaluating non-pharmacological interventions for postoperative delirium prevention in adult ICU or critical care patients. The primary outcome was postoperative delirium incidence. Secondary outcomes included delirium duration, delirium severity, ICU length of stay, and postoperative sleep quality. Studies reporting sleep-related outcomes without directly assessing delirium were included only in the qualitative synthesis as indirect supportive evidence and were not used to estimate the preventive effect on delirium incidence. Results: A total of 26 studies were included in the qualitative synthesis, of which 14 provided sufficient dichotomous data for the primary meta-analysis of delirium incidence. The remaining studies contributed qualitative evidence on non-comparable delirium outcomes, sleep-related outcomes, or the management of established delirium. Non-pharmacological interventions significantly reduced the risk of postoperative delirium compared with control conditions (RR = 0.61; 95% CI: 0.48–0.78; I2 = 25.2%). Conclusions: Non-pharmacological interventions were associated with a significant reduction in postoperative delirium incidence among critically ill adult patients. The certainty of the evidence for this outcome was moderate, and an analysis restricted to randomized controlled trials produced a consistent result. Further high-quality randomized controlled trials are required to standardize intervention protocols and clarify their effects on secondary clinical outcomes.