Dexmedetomidine for sedation following cardiovascular surgery: a two different loading doses

Introduction

Dexmedetomidine (DEX) is a selective alpha-2-adrenergic agonist used for sedation of patients in ICUs.

Hypothesis

The purpose of this study was to evaluate the efficacy and safety of DEX administration after cardiovascular surgery using two different loading doses.

Methods

This was a prospective, multicenter (three sites), randomized, open study. Patients were randomized to either a loading dose of 6 μg/kg/hour (group I) for 10 min or 3 μg/kg/hour (group II) for 20 min, with a total loading dose of 1 μg/kg, followed by a maintenance infusion of 0.4 μg/kg/hour, adjusted according to sedation level from 0.2 to 0.7 μg/kg/hour (Ramsay sedation scale >3 for mechanically ventilated patients and >2 after extubation). The sedation period with DEX ranged from 6 to 24 hours, beginning in the first hour after the patient's arrival in the postoperative ICU.

Results

Forty-two patients were studied after elective cardiovascular surgery (34 CABG, four aortic aneurysms, four valvular heart surgery). Eighty-eight percent of patients demonstrated no need for additional sedative drugs during mechanical ventilation. Twenty-six percent of patients received analgesics while intubated. The level of sedation, evaluated based on the Ramsay sedation scale, did not show any difference between the two groups during the 24-hour infusion. No differences have been found in the heart rate, systolic blood pressure, central venous pressure and pulse oxymeter saturation between the two groups during the 24-hour period.

Conclusions

Our study indicates that DEX is an effective and safe drug to be used in the postoperative period of cardiovascular surgery, independent of the loading dose rate infusion.