THE EFFECT OF INTRATHECAL SODIUM-NITROPRUSSIDE ON SEVERE CHRONIC VASOSPASM

The efficacy of sodium nitroprusside in resolving cerebral vasospasm w as evaluated with multicisternal injections. Twelve animals received f resh, unheparinized arterial blood via three injections (15 ml total) into the cisterna magna. Selective vertebral arteriography was perform ed on Day 0, and blood injections were performed on the second and thi rd days after the first injection. On the seventh day selective arteri ography was performed to evaluate the diameter of the basilar artery. In the sodium nitroprusside group, intrathecal injections of the drug were started on Day 4 and continued for two days (25 mug/kg/day). The diameter of the basilar artery was reduced 72.98 +/- 11.07% in control experiments. For the animals treated with intrathecal sodium nitropru sside, the mean diameter of the basilar artery was reduced 29.25 +/- 4 .54%. The effect of intrathecal sodium nitroprusside on intracranial p ressure (ICP), blood pressure (BP) and electrocardiogram (ECG) was als o evaluated in 14 animals. There were no prominent changes in ICP, BP, or ECG when sodium nitroprusside was given intrathecally, but BP decr eased and ICP and heart rate increased with intravenous doses of sodiu m nitroprusside. These results support the hypothesis that sodium nitr oprusside administered intrathecally is an effective treatment for cer ebral vasospasm.