Clinical and pharmacokinetic comparative study of sufentanil and fentanyl in supratentorial neurosurgery

: The pharmacokinetic and the effects of sufentanil (S) and fentanyl (F) on cardiovascular stability, brain swelling, respiratory depression and post operative status were studied in 30 neurosurgical patients (group S, n = 15; group F, n = 15). Anesthesia was induced with sufentanil and fentanyl given intravenously (bolus injection 2.5 micrograms.kg-1 vs 25 micrograms.kg-1) followed by a constant rate infusion (0.25 vs 2.5 micrograms.kg-1 x h-1) and a sleep dose of thiopental (3 mg.kg-1) and pancuronium (0.1 mg.kg-1). If necessary, patients could receive more narcotic and, for sudden arousal, a dose of thiopental. Plasma concentrations of sufentanil and fentanyl were measured during and up to 12 hours after infusion. After induction bolus, mean arterial pressure decreased significantly (-30%) with sufentanil. In the group 5, the baseline heart rate and arterial pressure were lower and more stable than in the group F. Brain relaxation always seemed satisfactory. For all but 12 patients with sever neurological status, recovery and extubation times were less than 2 hours and allowed early neurological evaluation. Respiratory depression required naloxone for 2 patients with fentanyl. The plasma clearance of sufentanil and fentanyl (902 vs 914 ml.min-1) are similar. The volumes of distribution are respectively 4.9 and 11.3 l.kg-1, and the half-life 250 and 562 min. The wider volume of distribution and the great half-life compared with previous studies are attributed to corticoid, osmotic and diuretic preoperative treatment.