Dexmedetomidine in Prevention of Postoperative Delirium: A Systematic Review

Delirium is defined by the DSM-5 as a fluctuating course of disturbance in attention, cognition, and awareness that develops over a short period without any pre-existing neurocognitive disorder. As people age, there is an increased risk of complications that may occur following a surgical procedure and one such acute complication is delirium. Studies are emerging to reduce the incidence of postoperative delirium, and one such preventive measures implemented in recent years include the administration of dexmedetomidine, a high selectivity alpha-2 adrenoceptor agonist. This study aims to review the efficacy of Dexmedetomidine in the prevention of postoperative delirium in randomized controlled trials in patients older than 18 years of age. The literature was explored in three online databases, namely, PubMed, Science Direct, and Scopus. Appropriate keywords and MesH terms were employed to scrutinize relevant articles that demonstrated the effects of dexmedetomidine in the prevention of postoperative delirium. The data was restricted to randomized controlled trials and clinical trials published from 2017 to 2021 in human patients older than >18 years of age undergoing non-cardiac-related procedures. The randomized clinical trials were critically assessed with the Cochrane risk of bias tool. We proceeded to screen 428 records with the assessment of the PRISMA chart and filtered out 420 papers to obtain a total of eight studies where we identified data such as sample size, types of surgeries in which the patients were involved, the delirium assessment tool, the plan of the administration of dexmedetomidine and the outcomes evaluated in each study. The Confusion Assessment Method (CAM) was the prevailing assessment tool used with the sole purpose to evaluate the incidence of postoperative delirium as the primary outcome, and assessment of inflammatory cytokines, sleep quality, and pain scales were considered as secondary outcomes. The dosage of dexmedetomidine varied among studies, and it displayed varying impacts on postoperative delirium and the secondary outcomes as well. Limitations include varying ages and ethnicities of the population. It was concluded that dexmedetomidine prevents the development of postoperative delirium in elderly patients undergoing noncardiac surgical interventions by modulating important predisposing factors such as neuroinflammation, pain, and sleep quality. No funding was made for this study.