Efficacy of Ketamine as an Adjuvant to Scalp Block for Hemodynamic Stability in Patients Undergoing Elective Craniotomy for Supratentorial Glioma: A Prospective Randomized Controlled Trial.

Introduction  Scalp nerve block (SNB) attenuates the hemodynamic response to pin insertion and delivers excellent postoperative analgesia. This study aimed to evaluate the efficacy of SNB using ketamine as an adjuvant to bupivacaine on perioperative hemodynamic responses and postoperative pain in patients undergoing craniotomy for supratentorial glioma. Materials and Methods  Sixty patients were randomized into two groups. They were given scalp nerve block either with bupivacaine and saline (group S) or bupivacaine and ketamine (group K). Primary outcome was to compare the change in mean arterial pressure (MAP) and heart rate (HR) at defined time points from baseline. Secondary outcomes included time to request for first analgesia, total analgesic consumption in intraoperative and postoperative periods till 24 hours, and numeric rating scale pain score at various time points in postoperative period till 24 hours. Results  Fifty-seven patients were included in analysis. HR and MAP were comparable intraoperatively till closure. As soon as closure began, a significant increase in HR (group K vs. group S, 69.76 ± 9.03 vs. 93.96 ± 9.98, p -value = < 0.0001) and MAP (group K vs. group S, 79.4 ± 4.12 vs. 87.17 ± 12.67, p -value = 0.002) was noted in group S patients. This increase persisted in the postoperative period as well. The median total opioid consumed during intraoperative period in group K was 200 mcg versus 300 mcg in group S, p -value < 0.0001. Conclusion  Adding ketamine as an adjuvant to bupivacaine for SNB not only provides significant hemodynamic stability but also reduces both intra- and postoperative analgesic consumption.