Intracranial and hemodynamic changes after succinylcholine administration in cats.

Bolus injections of succinylcholine (1.5 mg/kg) significantly increased intracranial pressure (ICP) in cats under normal conditions from control levels of 8 +/- 1 mm Hg to 16 +/- 3 mm Hg (+/- SEM, P less than 0.01), and in the presence of artificially increased ICP from control levels of 27 +/- 1 mm Hg to 47 +/- 4 mm Hg (P less than 0.01). These approximately 100% increases in ICP were accompanied by a transitory decrease in mean arterial pressure (approximately 10 sec), followed by a 15-20% increase (P less than 0.05). Pulmonary arterial pressure increased 20-30% (P less than 0.05). These results, when considered in conjunction with results previously obtained in humans, suggest that succinylcholine may be contraindicated in neurosurgical patients.