Effects of nonpharmacological interventions on sleep improvement and delirium prevention in critically ill patients: A systematic review and meta-analysis

Objective Sleep disturbance and delirium are common problems experienced by critically ill patients in the intensive care unit (ICU). These interrelated issues increase the length of stay in the ICU but might also negatively affect long-term health outcomes. The objective of this study was to identify the nonpharmacological interventions provided to improve sleep or prevent delirium in ICU patients or both and integrate their effect sizes. Review methods This study was a registered systematic review and meta-analysis. We searched MEDLINE, CINAHL, EMBASE, Web of Science, and Cochrane Library from their inception until December 2021. We included randomised controlled trials and nonrandomised controlled trials-(RCT) that provided nonpharmacological interventions and reported sleep or delirium as outcome variables. Studies not published in English or whose full text was not available were excluded. The quality of the evidence was assessed with version 2 of the Cochrane risk-of-bias tool for RCTs and the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I). Results The systematic review included 118 studies, and the meta-analysis included 100 studies. Overall nonpharmacological interventions had significant effects on subjective sleep quality (standardised mean difference = 0.30, 95% confidence interval [CI] = 0.05 to 0.56), delirium incidence (odds ratio = 0.62, 95% CI = 0.53 to 0.73), and delirium duration (standardised mean difference = −0.68, 95% CI = −0.93 to −0.43). In individual interventions, aromatherapy, music, and massage effectively improved sleep. Exercise, family participation, information giving, cognitive stimulation, bright light therapy, architectural intervention, and bundles/protocols effectively reduced delirium. Light/noise blocking was the only intervention that ensured both sleep improvement and delirium prevention. Conclusions Our results suggest nonpharmacological interventions improve sleep and prevent delirium in ICU patients. We recommend that ICU nurses use nonpharmacological interventions that promote person–environment compatibility in their clinical practice. The results of our review can guide nurses in adopting interventions related to sleep and delirium. Prospero reference number CRD42021230815