INTRACRANIAL-PRESSURE AND HEMODYNAMIC-EFFECTS OF REMIFENTANIL VERSUS ALFENTANIL IN PATIENTS UNDERGOING SUPRATENTORIAL CRANIOTOMY

Remifentanil hydrochloride is an ultra-short-acting esterase metaboliz ed mu-opioid receptor agonist. The purpose of this study was to provid e preliminary information regarding the effects of this drug on intrac ranial pressure (ICP) and mean arterial pressure (MAP) in patients sch eduled for craniotomy. Twenty-six patients undergoing excision of supr atentorial space-occupying lesions were anesthetized with 0.3-0.8 vol% isoflurane in a 2:1 mixture of nitrous oxide:oxygen. Ventilation was adjusted to provide a PaCO2 of < 30 mm Hg. After the first burr hole w as drilled, patients (n = 5-6 per group) were administered an intraven ous infusion of study drug (placebo, remifentanil 0.5 mu g/kg or 1.0 m u g/kg, or alfentanil 10 mu g/kg or 20 mu g/kg) over 1 min. Epidural I CP and MAP values were recorded at baseline, at completion of infusion , and every minute for thf next 10 min. Blood study drug concentration s were measured immediately after completion of infusion. Neither opio id caused a significant increase in ICP. Both drugs were associated wi th a dose-dependent decrease in MAP. Remifentanil was 31 times more po tent than alfentanil for effects on MAP. We conclude that remifentanil produces similar cerebral perfusion pressure effects as does alfentan il.