The Opioid-sparing Effect of Intraoperative Dexmedetomidine Infusion After Craniotomy.

BACKGROUND We conducted a randomized trial to evaluate the opioid-sparing effect of an intraoperative infusion of dexmedetomidine (DEX) after craniotomy. METHODS Sixty adult patients scheduled for craniotomy were divided randomly into group A (DEX infusion at 0.5 μg/kg/h for 10 min and then adjusted to 0.2 to 0.5 μg/kg/h from tracheal intubation to incision suturing) and group B (0.9% saline infusion). Additional intravenous injections and patient-controlled analgesia with morphine were used to control postoperative pain for verbal Numerical Rating Scale scores >4. Cumulative morphine consumption, Numerical Rating Scale pain score, and the Ramsay Sedation Scale score were evaluated at 1, 2, 4, 6, 8, 12, and 24 hours; the incidence of postoperative nausea and vomiting, agitation, and respiratory depression were recorded at 24 hours after surgery. RESULTS Postoperative pain scores within 12 hours and Ramsay Sedation Scale scores within 6 hours of surgery were both significantly lower in group A than in group B (P<0.001). Patients in group A required 54.4%, 43.3%, and 31.4% less cumulative morphine consumption during the first 4, 12, and 24 hours, respectively. No patient in group A and 5 patients in group B presented agitation within 1 hour after surgery. Three patients in group A and 9 patients in group B showed pruritus (P<0.001). CONCLUSIONS An intraoperative infusion of DEX reduced cumulative morphine consumption and adverse effects after craniotomy.