Use of dexmedetomidine as a sedative and analgesic agent in critically ill adult patients: a meta-analysis

To assess the effects of using dexmedetomidine as a sedative and analgesic agent on length of intensive care unit (ICU) stay, duration of mechanical ventilation, risk of bradycardia, and hypotension in critically ill adult patients. Two researchers searched MEDLINE, EMBASE, and the Cochrane controlled trial register independently for randomized controlled trials comparing dexmedetomidine with a placebo or an alternative sedative agent, without any language restrictions. A total of 2,419 critically ill patients from 24 trials were subject to meta-analysis. Dexmedetomidine was associated with a significant reduction in length of ICU stay [weighted mean difference -0.48 days, 95% confidence interval (CI) -0.18 to -0.78 days, P = 0.002], but not duration of mechanical ventilation, when compared with an alternative sedative agent. There was, however, significant heterogeneity in these two outcomes between the pooled studies. Dexmedetomidine was associated with increased risk of bradycardia requiring interventions in studies that used both a loading dose and maintenance doses > 0.7 mu g kg(-1) h(-1) [relative risk (RR) 7.30, 95% CI 1.73-30.81, P = 0.007]. Risks of hypotension requiring interventions (RR 1.43, 95% CI 0.78-2.6, P = 0.25), delirium (RR 0.79, 95% CI 0.56-1.11, P = 0.18), self-extubation, myocardial infarction, hyperglycemia, atrial fibrillation, and mortality were not significantly different between dexmedetomidine and traditional sedative and analgesic agents. Significant heterogeneity existed between the pooled studies. The limited evidence suggested that dexmedetomidine might reduce length of ICU stay in some critically ill patients, but the risk of bradycardia was significantly higher when both a loading dose and high maintenance doses (> 0.7 mu g kg(-1) h(-1)) were used.