Effect of prostaglandin E1-induced hypotension on carbon dioxide reactivity and local cerebral blood flow after subarachnoid haemorrhage.

The effect of prostaglandin E1 (PGE1) on local cerebral blood flow (LCBF) and carbon dioxide reactivity (CO2R) was studied during cerebral aneurysm surgery for subarachnoid haemorrhage in 24 patients under neuroleptanaesthesia. Eleven patients had good neurological status (Hunt and Kosnik grade I: group A) and 13 patients poor status (grades II-IV: group B). Arterial hypotension was induced with PGE1 0.1 micrograms kg-1 min-1 initially and adjusted to maintain mean arterial pressure at about 70 mm Hg. PGE1 was discontinued at the completion of aneurysm clipping. LCBF and CO2R were measured during and after administration of PGE1. LCBF was unchanged and CO2R preserved in both groups. The carbon dioxide response was better in group A than in group B (P less than 0.01). PGE1 may be a suitable agent for hypotensive anaesthesia in these patients.