SPINAL-CORD BLOOD-FLOW DURING PROSTAGLANDIN E(1) INDUCED HYPOTENSION

To evaluate the effect of prostaglandin E(1) (PGE(1)) induced hypotension on spinal blood flow (SBF) during spinal surgery, SBF was measured under isoflurane anaesthesia by the heat clearance method in 10 patients with spinal tumour. An initial dose of 0.1 mu g/kg/min of PGE(1) was administered intravenously after spinal opening and the dose was adjusted to maintain the mean arterial blood pressure (MAP) at about 60 mmHg. PGE(1) was discontinued at the completion of the operative produces. After starting PGE(1), MAP and rate pressure product (RPP) decreased significantly compared with preinfusion values (P < 0.01), and the hypotensive effect of PGE(1) remained constant at 60 min after its discontinuation. Heart rate (HR) did not change throughout the study. SBF showed no change over the course of PGE(1) induced hypotension (preinfusion : 47.8 +/- 21.7 ml/100 g/min, at 15 min : 41.2 +/- 16.9 ml/100 g/min, at 30 min : 40.4 +/- 16.8 ml/100 gl min, and at 60 min : 46.1 +/- 16.3 ml/100 g/min, respectively). These results suggest that PGE(1) may be a useful drug for hypotensive anaesthesia in surgery for spinal cord tumours because PGE(1) maintained SBF.