Effect of Intraoperative Dexmedetomidine on Post-Craniotomy Pain

Purpose Pain management for patients who have undergone a craniotomy remains challenging. This study aimed to determine whether intraoperative dexmedetomidine could reduce postoperative pain, analgesic consumption, and possible adverse events in patients after craniotomy. Methods Eighty patients scheduled for elective supratentorial craniotomy under sevoflurane-fentanyl anesthesia were randomly allocated into two equal groups, to receive a continuous dexmedetomidine infusion of 0.5 µg/kg/h or placebo, beginning after induction and continuing until the start of skin closure. Intravenous tramadol (0.5 mg/kg) was administered to achieve an 11-point verbal rating scale (a discrete 0–10 scale) score of 4 or less in the postanesthesia care unit and, thereafter, on the ward. Pain scores, tramadol consumption, sedation scores, postoperative nausea and vomiting (PONV) scores, and other adverse events were recorded in the first 24 hours postoperatively. Findings Seventy-six patients were included in the analyses. Demographic data, surgical characteristics, and sedation levels were similar between the groups. Dexmedetomidine reduced pain scores (30 minutes, P = 0.041; 2 hours, P = 0.021) and tramadol consumption (0–2 hours, P = 0.043; 0–6 hours, P = 0.006; 0–12 hours, P = 0.023; 0–24 hours, P = 0.040) postoperatively. Dexmedetomidine also reduced PONV scores at 20, 60, 90, 120, and 240 minutes (P = 0.038, 0.022, 0.018, 0.037, 0.016, respectively). The dexmedetomidine group exhibited fewer PONV events that required treatment (P = 0.005). Implications Intraoperative dexmedetomidine infusion was effective for reducing pain and analgesic consumption after craniotomy. In addition, dexmedetomidine may help to reduce PONV in patients after craniotomy treated with tramadol postoperatively. Chinese Clinical Trial Register identifier: ChiCTR-TRC-13003598.