Low-dose Dexmedetomidine Improves Sleep Quality Pattern in Elderly Patients after Noncardiac Surgery in the Intensive Care Unit

Patients admitted to the intensive care unit (ICU) after surgery often develop sleep disturbances. The authors tested the hypothesis that low-dose dexmedetomidine infusion could improve sleep architecture in nonmechanically ventilated elderly patients in the ICU after surgery.This was a pilot, randomized controlled trial. Seventy-six patients age 65 yr or older who were admitted to the ICU after noncardiac surgery and did not require mechanical ventilation were randomized to receive dexmedetomidine (continuous infusion at a rate of 0.1 μg kg h; n = 38) or placebo (n = 38) for 15 h, i.e., from 5:00 PM on the day of surgery until 8:00 AM on the first day after surgery. Polysomnogram was monitored during the period of study-drug infusion. The primary endpoint was the percentage of stage 2 non-rapid eye movement (stage N2) sleep.Complete polysomnogram recordings were obtained in 61 patients (30 in the placebo group and 31 in the dexmedetomidine group). Dexmedetomidine infusion increased the percentage of stage N2 sleep from median 15.8% (interquartile range, 1.3 to 62.8) with placebo to 43.5% (16.6 to 80.2) with dexmedetomidine (difference, 14.7%; 95% CI, 0.0 to 31.9; P = 0.048); it also prolonged the total sleep time, decreased the percentage of stage N1 sleep, increased the sleep efficiency, and improved the subjective sleep quality. Dexmedetomidine increased the incidence of hypotension without significant intervention.In nonmechanically ventilated elderly patients who were admitted to the ICU after noncardiac surgery, the prophylactic low-dose dexmedetomidine infusion may improve overall sleep quality.