Adrenaline-induced hypotension in neurosurgery.

We have compared the effects of scalp infiltration with 0.5% lignocaine, 0.5% lignocaine with adrenaline 1:200,000, 0.9% saline and 0.9% saline with adrenaline 1:200,000, in a prospective, randomized, double-blind study. Direct arterial pressure, heart rate and bleeding at incision were recorded in 80 patients undergoing craniotomy or craniectomy. Arterial pressure decreased by more than 20% from preinfiltration values in 40% of patients in the saline with adrenaline group, and in 55% of patients in the lignocaine with adrenaline group. It did not decrease in patients who did not receive adrenaline.