Use of sodium nitroprusside in neurosurgical cases during anesthesia with enflurane

In patients operated for cerebral aneurysm or angioma, the same basic method of anesthesia has been used. Premedication consisted of Thalamonal or diazepam. After induction with thiopentone, curarisation with pancuronium and tracheal intubation, anesthesia was maintained with N2O 70%, O2 30% and enflurane 1%. Small doses of fentanyl or Thalamonal were given at the beginning of anesthesia, but no more within 30 minutes before starting controlled hypotension. Adjuvant drugs and methods to reduce intracranial pressure were also used, such as dexamethasone, mannitol and cerebro-spinal fluid subtraction. The approach and dissection of the vascular lesion was done under controlled hypotension with sodium nitroprusside 0.01% solution. The mean dose of sodium nitroprusside to maintain a mean blood pressure at about 50 Torr was 1.37 mcg/kg/min.