Lidocaine or thiopental for rapid control of intracranial hypertension?

The effectiveness of intravenously administered lidocaine for rapid control of acute intracranial hypertension was compared to the effectiveness of thiopental in 20 patients with brain tumors undergoing craniotomy. Despite normal radial arterial and intracranial pressures (ICP) after induction of N2O-O2-morphine anesthesia, mean ICP increased from 13.8 torr +/- 1.5 SE to 31 torr +/- 2.3 SE (p less than 0.001) in response to application of a pin-holder or scalp incision. To treat the elevated ICP a bolus injection of lidocaine, 1.5 mg/kg IV, was given to 10 patients, whereas the other 10 received thiopental, 3 mg/kg IV. Lidocaine reduced ICP 15.7 torr +/- 5.6 SE (p less than 0.025) did not significantly affect mean arterial pressure. In contrast, thiopental lowered ICP 18.4 torr +/- 9.6 SE (p less than 0.02) and also lowered mean arterial pressure by 26.1 torr +/- 9.6 SE (p less than 0.025). Mean time for injection of medication to ICP nadir was 66 seconds +/- 10 SE after lidocaine versus 48 seconds +/- 9 SE after thiopental (p greater than 0.20). It is concluded that lidocaine is as effective as thiopental for rapid reduction of intraoperative intracranial hypertension but that it causes less cardiovascular depression. Lidocaine may be of particular benefit to patients with both intracranial hypertension and marginal circulatory function.