Effects of an Intraoperative Dexmedetomidine Bolus on the Postoperative Blood Pressure and Pain Subsequent to Craniotomy for Supratentorial Tumors

Background: Control of emergence hypertension and pain is important after craniotomy for monitoring the neurological status. This prospective double-blinded study investigated the hemodynamics after a single bolus of dexmedetomidine (DEX) infusion administered to the patient undergoing craniotomy under general anesthesia, and its effect on emergence hypertension and postsurgical pain. Methods: Adult patients scheduled for elective surgery for supratentorial tumors were randomized to receive a 10-minute intraoperative DEX infusion of 0.4 &mgr;g/kg (small dose, n=43) or 0.8 &mgr;g/kg (medium dose, n=46), or normal saline (vehicle control, n=45), ∼60 minutes before the end of anesthesia. Results: A transient increase in the blood pressure associated with DEX was observed; 53.5% and 91.3% of the patients in the small-dose and the medium-dose groups, respectively, required treatment. Emergence mean arterial pressure and heart rates were significantly lower in the DEX groups compared with the control group. Incidence rates of postoperative hypertension in the small-dose (16.3%) and the medium-dose groups (15.2%) were significantly lower relative to that of the control group (35.6%). Patients who received DEX had a lower Verbal Numerical Rating Scale (VNRS) score in the neurosurgical ICU than the control group, and postsurgical pain (VNRS≥4) was lower in the medium-dose group (41.3%) than in the control group (71.1%). No shivering was observed in the medium-dose group, which was significantly less than that of the other 2 groups. Conclusions: An intraoperative bolus of DEX risks a transient increase in mean arterial pressure, but controls emergence hypertension effectively. Dose-related reductions in postsurgical pain and shivering were observed.