Effect of early cognitive interventions on delirium in critically ill patients: a systematic review

PURPOSE: A systematic review of the literature was conducted to determine the effects of early cognitive interventions on delirium outcomes in critically ill patients. SOURCE: Search strategies were developed for MEDLINE, EMBASE, Joanna Briggs Institute, Cochrane, Scopus, and CINAHL databases. Eligible studies described the application of early cognitive interventions for delirium prevention or treatment within any intensive care setting. Study designs included randomized-controlled trials, quasi-experimental trials, and pre/post interventional trials. Two reviewers independently extracted data and assessed risk of bias using Cochrane methodology. PRINCIPAL FINDINGS: Four hundred and four citations were found. Seven full-text articles were included in the final review. Six of the included studies had an overall serious, high, or critical risk of bias. After application of cognitive intervention protocols, a significant reduction in delirium incidence, duration, occurrence, and development was found in four studies. Feasibility of cognitive interventions was measured in three studies. Cognitive stimulation techniques were described in the majority of studies. CONCLUSION: The study of early cognitive interventions in critically ill patients was identified in a small number of studies with limited sample sizes. An overall high risk of bias and variability within protocols limit the utility of the findings for widespread practice implications. This review may help to promote future large, multi-centre trials studying the addition of cognitive interventions to current delirium prevention practices. The need for robust data is essential to support the implementation of early cognitive interventions protocols.