Preoperative Versus Postoperative Scalp Block Combined with Incision Line Infiltration for Pain Control after Supratentorial Craniotomy

Objective: Postoperative pain after craniotomy is a significant clinical problem that is sometimes underestimated, although moderate or severe pain in early postoperative period complicates up to 60% of cases. The purpose of this prospective randomized multicenter trial was to determine the optimal timing for selective scalp block in patients undergoing general anesthesia for supratentorial craniotomy. Materials and Methods: After ethics committee approval and informed consent, 56 adult patients were enrolled, and randomly assigned to receive a selective scalp block combined with incision line infiltration preoperatively or postoperatively. Results: Postoperative pain at 24 hours after the procedure was recorded in all 56 enrolled patients. In patients assigned to receive a scalp block preoperatively, median VAS score at 24 hours after surgery was 0 (0 to 2), and in patients assigned to receive a scalp block postoperatively it was 0 (0 to 3) (P>0.05). There was no difference in severity of pain at 24, 12, 6, and 2 hours after surgery between the 2 study groups, but the amount of fentanyl administered intraoperatively was lower in patients assigned to the preoperative scalp block group (1.6±0.7 vs. 2.4±0.7 mkg/kg/h, P=0.01). Discussion: This study confirms and extends available clinical evidence on the safety and efficacy of selective scalp blocks for the prevention of postoperative pain. Recorded data suggest that there is no difference in terms of occurrence and severity of postoperative pain regardless of whether the scalp block is performed preoperatively (after general anesthesia induction) or postoperatively (before extubation). Patients assigned to receive a scalp block combined with incision line infiltration preoperatively needed less intraoperative opioids than those assigned to postoperative scalp block.