Comparison of effects of dexmedetomidine added to ropivacaine versus ropivacaine alone infiltration scalp block for attenuation of the haemodynamic response to skull pin placement in neurosurgical procedures: A double-blind, randomised clinical trial

Abstract

Background and aims: Skull pin head holder application is intensely painful and is accompanied with abrupt increase in heart rate and arterial blood pressure. We aimed to determine the effects of adding dexmedetomidine to ropivacaine scalp block in attenuating the haemodynamic response to skull pin insertion in neurosurgical procedures.

Methods: Sixty patients were randomly allocated to receive scalp block with 25 ml of 0.5% ropivacaine added with either normal saline (control group) or dexmedetomidine (1 μg/kg) after anesthesia induction. A standard uniform general endotracheal anaesthesia protocol was followed in all study subjects. Heart rate and blood pressure measurements were made at baseline, 1, 3, 5, 10, and 15 min following skull pin placement. Student's independent t-test, Chi-square test and repeated measure analysis of variance were used to analyse the obtained data.

Results: There was no significant attenuation of heart rate (P = 0.418), systolic (P = 0.542), diastolic (P = 0.793) and mean blood pressure (P = 0.478) with addition of dexmedetomidine to ropivacaine.

Conclusions: The addition of dexmedetomidine (1 μg/kg) to 25 ml of 0.5% ropivacaine offers no additional benefit over 25 ml of 0.5% ropivacaine alone scalp block in attenuating the haemodynamic response to skull pin placement in neurosurgical procedures.

Keywords: Blood pressure; dexmedetomidine; heart rate; nerve block; ropivacaine.

Figure 1

CONSORT diagram; MV: Mechanical ventilation

Figure 2

Episodes of bradycardia, tachycardia, hypotension, hypertension