Effect of scalp infiltration on postoperative pain relief in elective supratentorial craniotomy with 0.5% bupivacaine with adrenaline 1:400,000

Abstract

Objective: Determine the effect of scalp infiltration on postoperative craniotomy pain with 0.5% bupivacaine with adrenaline 1:400,000. Material and Method: A prospective randomized double blind control trial was conducted on 50 patients (18-65 years), who were ASA physical status I to III, and scheduled for elective intracranial surgery at Maharaj Nakorn Chiang Mai Hospital, Thailand between October 2006 and December 2007. The patients received wound infiltration before skin closure by either 0.5% bupivacaine with adrenaline 1:400,000 (group B), or normal saline with adrenaline 1:400,000 (group S). Results: The median pain score in the first 12 hours trended to be lower in the bupivacaine group than in the control, but the differences were not statistically significant apart from the score in the first hour (median pain score = 2, IQR = 3; p = 0.031). There were more pain-free patients in the bupivacaine group than in the control group at all time intervals during the first 12 hours. However, the difference was significant in the first hour (7 vs. 1; p = 0.034). Although the median (range) time interval between the end of surgery and first administration of tramadol was longer in the bupivacaine group, when compared to the control group, it was not statistically significant. Conclusion: Surgical wound infiltration, before skin closure, with 0.5% bupivacaine with adrenaline decreased the incidence and severity of postoperative pain in patients undergoing supratentorial craniotomy, but only for the first hour after surgery.