[Hypotension induced by isoflurane for the treatment of intracranial aneurysm in late pregnancy].

A 31-year old primigravida was admitted at 31 week gestation for subarachnoid haemorrhage. Cerebral angiography revealed an aneurysm on the left middle cerebral artery. Eleven days later, the aneurysm was clipped off. General anaesthesia was induced with thiopentone, pancuronium and fentanyl, and maintained with fentanyl (40 micrograms.kg-1) and isoflurane in air/O2 with a non-rebreathing circuit. The patient was mechanically ventilated to maintain mild hypocapnia. Arterial hypotension was induced by increasing the inspired isoflurane concentration from 1 to 3 vol%. The response was immediate and a mean arterial pressure of 60 mmHg was maintained for 80 min with an inspired isoflurane concentration of 2.5 vol%. Foetal heart rate was monitored before, during and after general anaesthesia. Loss of beat to beat variation was observed after induction, and foetal heart rate slowly decreased from 150 to 115 b.min-1 at the end of the operation. Postoperative state was good, except for transitory aphasia. At 35 week gestation, the patient went into premature labour, with hypothermia of 39.5 degrees C; an emergency caesarean section was performed. The 2,340 g female infant had a 10 min Apgar score of 8. One month later, clinical examination of the mother and daughter was quite normal. The precautions and anaesthetic management of patients suffering from ruptured cerebral aneurysm during the end of pregnancy are reviewed. Hypotensive agents are discussed.