Assessment of melatonergics in prevention of delirium in critically ill patients: A protocol for systematic review and meta-analysis

Prophylactic Melatonin for Delirium in Intensive Care Unit: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials

Introduction

Delirium, being a common disorder among critically ill patients, has a reported incidence ranging 45-83% in the intensive care unit (ICU) population. The prophylactic use of melatonin and melatonergics has been shown to have a positive effect in reducing the incidence of delirium in many clinical trials. Our study was thus proposed to find out the role of melatonin on the incidence and severity of ICU delirium, ICU and hospital length of stay (LOS), requirement, duration of mechanical ventilation, and ICU mortality.

Methodology

A systematic search of various databases was performed to find out the trials which compare melatonin with a placebo or standard therapy for delirium prevention with the results conveyed as mean differences (MDs) or risk ratios. The statistical software, Review Manager (RevMan, version 5.4), was used for data synthesis.

Results

Twelve studies were included in the meta-analysis. Prophylactic administration of melatonin or ramelteon was not associated with a statistically significant reduction in the incidence of delirium (odds ratio [OR] 0.63; confidence interval [CI]: 0.60, 1.32; p = 0.22), the severity of delirium (MD: 0.22; 95% CI: From -1.36 to 1.81; p = 0.78), ICU LOS (MD: 0.05; 95% CI: From -0.65 to 0.75; p = 0.89), hospital LOS (MD: -1.46; 95% CI: From -4.50 to -1.59; p = 0.35), need for mechanical ventilation (OR: 0.74, 95% CI: 0.38-1.44; p = 0.37), and ICU mortality (MD: 0.78; 95% CI: 0.56; 1.11; p = 0.62). However, a significant reduction in the duration of mechanical ventilation (MD: -0.85; 95% CI: From -1.64 to -0.06; p = 0.03) was found.

Conclusion

Our meta-analysis suggests that melatonin when given prophylactically has no significant role in reducing the incidence and severity of delirium, ICU and hospital LOS, need for mechanical ventilation, duration of mechanical ventilation, and ICU mortality. Further studies are warranted.

How to cite this article

Mukundarajan R, Soni KD, Trikha A. Prophylactic Melatonin for Delirium in Intensive Care Unit: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials. Indian J Crit Care Med 2023;27(9):675-685.

Assessment of Melatonergics in Prevention of Delirium: A Systematic Review and Meta-Analysis

Background: Delirium is a commonly found comorbidity in hospitalized patients and is associated with adverse outcomes. Melatonin is an endogenous hormone that exerts multiple biological effects, mainly in regulating diurnal rhythms and in inflammatory process and immune responses. We aimed to assess the efficacy of exogenous melatonergics in the prevention of delirium.

Methods: We conducted a search to identify relevant randomized controlled studies (RCTs) in PubMed, Cochrane Library, and EMBASE databases that had been published up to December 2019. Hospitalized adult patients administered melatonergics were included. The primary outcome measure was the incidence of delirium. The secondary outcome measure was the length of stay in intensive care unit (ICU-LOS). The pooled effects were analyzed as the risk ratio (RR) for delirium incidence, weighted mean difference (WMD) for ICU-LOS, and 95% confidence intervals (CIs).

Results: Nine RCTs with 1,210 patients were included. The forest plots showed that melatonergics were associated with a decreasing incidence of delirium (RR, 0.51; 95% CI, 0.30–0.85; I² = 70%; p = 0.01). There was no significant difference in ICU-LOS (WMD, −0.08; 95% CI, −0.19–0.03; I² = 0; p = 0.17).

Conclusion: Administration of exogenous melatonergics to hospitalized patients seems to be associated with a decreasing incidence of delirium.

PROSPERO registration number: CRD42019138863.