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Caring for the Critically Ill Patient
February 4, 2009

Dexmedetomidine vs Midazolam for Sedation of Critically Ill Patients: A Randomized Trial

Author Affiliations

Author Affiliations: University of Vermont College of Medicine and Maine Medical Center, Portland, Maine (Dr Riker); University of New South Wales Clinical School, The Prince of Wales Hospital Campus, Randwick, New South Wales, Australia (Dr Shehabi); Hospira Inc, Lake Forest, Illinois (Dr Bokesch and Mr Wisemandle); Carrera de Especialista en Medicina Crítica de la Universidad de Buenos Aires, Hospital General de Agudos Juan A. Fernández, Buenos Aires, Argentina (Dr Ceraso); University of Kentucky College of Medicine and Kentucky Lung Clinic, Hazard (Dr Koura); University of Illinois College of Medicine at OSF St Francis Medical Center, Peoria, Illinois (Dr Whitten); Resurrection West Suburban Hospital Medical Center, Oak Park, Illinois (Dr Margolis); Vanderbilt University Medical Center, Nashville, Tennessee (Mr Byrne and Dr Ely); Veterans Affairs Geriatric Research Education Clinical Center for the Tennessee Valley Healthcare System VA–the VA GRECC (Dr Ely); and Pavilhão Pereira Filho, Irmandade Santa Casa de Misericórdia, Porto Alegre, Brazil (Dr Rocha).

JAMA. 2009;301(5):489-499. doi:10.1001/jama.2009.56

Context γ-Aminobutyric acid receptor agonist medications are the most commonly used sedatives for intensive care unit (ICU) patients, yet preliminary evidence indicates that the α2 agonist dexmedetomidine may have distinct advantages.

Objective To compare the efficacy and safety of prolonged sedation with dexmedetomidine vs midazolam for mechanically ventilated patients.

Design, Setting, and Patients Prospective, double-blind, randomized trial conducted in 68 centers in 5 countries between March 2005 and August 2007 among 375 medical/surgical ICU patients with expected mechanical ventilation for more than 24 hours. Sedation level and delirium were assessed using the Richmond Agitation-Sedation Scale (RASS) and the Confusion Assessment Method for the ICU.

Interventions Dexmedetomidine (0.2-1.4 μg/kg per hour [n = 244]) or midazolam (0.02-0.1 mg/kg per hour [n = 122]) titrated to achieve light sedation (RASS scores between −2 and +1) from enrollment until extubation or 30 days.

Main Outcome Measures Percentage of time within target RASS range. Secondary end points included prevalence and duration of delirium, use of fentanyl and open-label midazolam, and nursing assessments. Additional outcomes included duration of mechanical ventilation, ICU length of stay, and adverse events.

Results There was no difference in percentage of time within the target RASS range (77.3% for dexmedetomidine group vs 75.1% for midazolam group; difference, 2.2% [95% confidence interval {CI}, −3.2% to 7.5%]; P = .18). The prevalence of delirium during treatment was 54% (n = 132/244) in dexmedetomidine-treated patients vs 76.6% (n = 93/122) in midazolam-treated patients (difference, 22.6% [95% CI, 14% to 33%]; P < .001). Median time to extubation was 1.9 days shorter in dexmedetomidine-treated patients (3.7 days [95% CI, 3.1 to 4.0] vs 5.6 days [95% CI, 4.6 to 5.9]; P = .01), and ICU length of stay was similar (5.9 days [95% CI, 5.7 to 7.0] vs 7.6 days [95% CI, 6.7 to 8.6]; P = .24). Dexmedetomidine-treated patients were more likely to develop bradycardia (42.2% [103/244] vs 18.9% [23/122]; P < .001), with a nonsignificant increase in the proportion requiring treatment (4.9% [12/244] vs 0.8% [1/122]; P = .07), but had a lower likelihood of tachycardia (25.4% [62/244] vs 44.3% [54/122]; P < .001) or hypertension requiring treatment (18.9% [46/244] vs 29.5% [36/122]; P = .02).

Conclusions There was no difference between dexmedetomidine and midazolam in time at targeted sedation level in mechanically ventilated ICU patients. At comparable sedation levels, dexmedetomidine-treated patients spent less time on the ventilator, experienced less delirium, and developed less tachycardia and hypertension. The most notable adverse effect of dexmedetomidine was bradycardia.

Trial Registration clinicaltrials.gov Identifier: NCT00216190

Trial Registration Published online February 2, 2009 (doi:10.1001/jama.2009.56).