Effect of bilateral scalp nerve blocks on postoperative pain and discharge times in patients undergoing supratentorial craniotomy and general anesthesia: a randomized-controlled trial

Purpose Post-craniotomy pain is a common clinical issue and its optimal management remains incompletely studied. Utilization of a regional scalp block has the potential advantage of reducing perioperative pain and opioid consumption, thereby facilitating optimal postoperative neurologic assessment. The purpose of this study was to assess the efficacy of regional scalp block on post-craniotomy pain and opioid consumption. Methods We performed a prospective randomized-controlled trial in adults scheduled to undergo elective supratentorial craniotomy under general anesthesia to assess the efficacy of postoperative bilateral scalp block with 0.5% bupivacaine with 1:200,000 epinephrine compared with placebo on postoperative pain and opioid consumption. The primary outcome was the visual analogue scale (VAS) for pain at 24 hr postoperatively. Results Eighty-nine patients were enrolled (n = 44 in block group; n = 45 in control group). There was no difference in the mean (standard deviation) VAS score at 24 hr postoperatively between the treatment group and the control group [31.2 (21.4) mm vs 23.0 (19.2) mm, respectively; mean difference, 6.6; 95% confidence interval, -2.3, 15.5; P = 0.15]. There was also no significant difference in postoperative opioid consumption. Distribution of individual VAS score and opioid consumption revealed that postoperative pain was highly variable following craniotomy. Time to hospital discharge was not different between treatment and placebo groups. No adverse events associated with scalp block were identified. Conclusion These data show that bilateral scalp blocks using bupivacaine with epinephrine did not reduce mean postoperative VAS score or overall opioid consumption at 24 hr nor the time-to-discharge from the postanesthesia care unit or from hospital.