Comparison of Efficacy of Scalp Infiltration of Bupivacaine Plus Dexmedetomidine and Bupivacaine Alone as Preemptive Analgesia to Blunt Hemodynamic Response to Craniotomy. Efficacy of dexmedetomidine and bupivacaine scalp infiltration

Background: Increase in heart rate and blood pressure are the prominent hemodynamic changes seen in response to various noxious stimuli in neurosurgical procedures. In patients with intracranial pathologies hypertension and tachycardia can result in raised intracranial pressure causing morbidity. The aim is to compare the effect of scalp infiltration of bupivacaine alone and bupivacaine plus dexmedetomidine to attenuate hemodynamic response to noxious stimuli during craniotomy under general anaesthesia. Material and Methods: Bupivacaine (n = 30) or bupivacaine with dexmedetomidine (n = 30) scalp infiltration was administered to sixty patients undergoing neurosurgeries in a prospective randomization study. Heart rate (HR) and mean arterial pressure (MAP) were recorded at baseline, after pin insertion, scalp incision, during duramater opening and closure, during skin closure, on admission to the post anesthesia care room (PACU) and 2 h after arrival in the PACU. Results: In PACU mean arterial pressure in group 1 was significantly more when compared to mean arterial blood pressure in group 2 (p= 0.04) and its baseline blood pressure. (p= 0.01) HR and MAP did not differ significantly across the groups at any of the other predetermined time periods or when compared to their baseline MAPs. Conclusion: Addition of dexmedetomidine with bupivacaine in local scalp infiltration offered no additional benefit in attenuating hemodynamic response to various sharp noxious stimuli in neurosurgical procedures However dexmedetomidine prolonged the analgesic effect of bupivacaine.

Keywords: General anaesthesia, Bupivacaine, Noxious stimuli.