Intravenous Dexmedetomidine Versus 0.5% Ropivacaine Scalp Block for Attenuation of Hemodynamic Response to Skull-Pin Insertion in Adult Craniotomy: A Prospective Randomized Double-Blind Study

Abstract

Background: Skull-pin fixation during craniotomy is associated with intense nociceptive stimulation leading to abrupt sympathetic activation, resulting in tachycardia, hypertension, and increased intracranial pressure. Effective attenuation of this hemodynamic response is essential in neurosurgical anaesthesia. This study compared the efficacy of intravenous dexmedetomidine infusion with 0.5% ropivacaine scalp block in attenuating hemodynamic responses following skull-pin insertion during elective craniotomy.
Materials and Methods: In this prospective randomized double-blind comparative study, 130 adult patients undergoing elective craniotomy under general anaesthesia were allocated into two groups. Group D (n=65) received intravenous dexmedetomidine infusion, while Group S (n=65) received bilateral scalp block with 0.5% ropivacaine. Hemodynamic parameters including heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded at baseline, before induction, before pinning, and at 0-10 minutes after skull-pin insertion.
Results: Demographic variables including age, weight, sex distribution, and ASA physical status were comparable between the two groups. Baseline HR was comparable between Group D and Group S (86.62 ± 16.43 vs 83.49 ± 17.26 beats/min; p=0.29). Following skull-pin insertion, HR values were significantly higher in Group D at 1-8 minutes post pinning compared with Group S (p <0.05). Similar trends were observed for SBP, DBP, and MAP, suggesting superior attenuation of hemodynamic responses with scalp block using 0.5% ropivacaine. Both techniques were clinically effective and associated with acceptable hemodynamic stability.
Conclusion: Scalp block with 0.5% ropivacaine demonstrated superior attenuation of the hemodynamic response to skull-pin insertion compared with intravenous dexmedetomidine infusion in adult patients undergoing elective craniotomy. Both interventions were safe and effective, although scalp block provided better control of sympathetic responses during skull-pin application.