Efficacy of bupivacaine infiltration in preventing haemodynamic changes during craniotomy

This study was carried out in sixty adult patients of either sex, to assess the efficacy of bupivacaine infiltration in different concentrations to prevent haemodynamic responses during craniotomy. The patients were randomly divided into 4 groups of15 each and scalp was infiltrated along the line of skin incision using either normal saline or 0.5, 0.25 or 0.125 bupivacaine. Patients were premedicated with morphine and promethazine and were anaestetised using conventional general anaesthesia technique including 02, N20 vecuronium and morphine. Ventilation was controlled so as to maintain PaCO2 between 25-30 mm Hg. EKG, heart rate and direct arterial pressure were monitored at various events during craniotomy. In control group there was a statistically significant increase in systolic arterial pressure and heart rate after scalp infiltration, scalp incision, during scalp flap reflection, burr hole formation, giglisaw operation and dural incision. In bupivacaine groups there was no significant alteration in arterial blood pressure or heart rate through out the period of study. On comparing the four groups it was observed that rise in arterial pressure and heart rate was significantly more in control group. Similarly a significantly more increasein systolic arterial pressure was observed in bupivacaine (0.125) group as compared to other trial groups. We recommend the haemodynamic changes during craniotomy.