title: Target-controlled infusion of alfentanil for postoperative analgesia: a feasibility study and pharmacodynamic evaluation in the early postoperative period.
abstract: We have examined the feasibility of target-controlled infusion of alfentanil (TCIA) and the pharmacodynamics of alfentanil in the early postoperative period. Patients were allocated randomly to one of the three groups to receive balanced anaesthesia with bolus injections of fentanyl (group F), sufentanil (group S) or alfentanil (group A). In the recovery room all patients received the same analgesic regimen, comprising TCIA. To evaluate the efficacy of postoperative analgesia, pain scores were measured on a visual analogue scale (VAS) and patients indicated a need for additional analgesia. EC50, the concentration at which, with a 50% probability, patients reported adequate analgesia, was estimated using logistic regression. Six patients did not complain of pain. The time from the last intraoperative bolus injection of opioid until patients complained of postoperative pain was shorter (P < 0.05) in group A (mean 68 min) than in group F (101 min) and group S (136 min). The time to onset of satisfactory analgesia was comparable in the three groups (median 18 min in group F, 15 min in group S and 14 min in group A). EC50 of alfentanil was determined in 28 patients; mean values were 26 ng ml-1 (group F), 39 ng ml-1 (group S) and 52 ng ml-1 (group A). We conclude that TCIA, under the conditions studied, resulted in a fast onset of adequate analgesia, irrespective of the opioid administered during operation. Also, there was no effect of opioids administered during operation on postoperative pharmacodynamics of alfentanil.
authors.affiliation: Department of Anaesthesiology, University Hospital Leiden, The Netherlands.
authors.forename: M C
authors.initials: MC
authors.lastname: Van den Nieuwenhuyzen
authors.forename: F H
authors.initials: FH
authors.lastname: Engbers
authors.forename: A G
authors.initials: AG
authors.lastname: Burm
authors.forename: A A
authors.initials: AA
authors.lastname: Vletter
authors.forename: J W
authors.initials: JW
authors.lastname: Van Kleef
authors.forename: J G
authors.initials: JG
authors.lastname: Bovill
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015760:Alfentanil / Q000008:administration & dosage* / Q000097:blood; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000097:blood; D000768:Anesthesia, General; D004360:Drug Therapy, Computer-Assisted; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*; D011184:Postoperative Period
chemical_list: D000701:Analgesics, Opioid; D015760:Alfentanil