Alfentanil pharmacokinetics in patients undergoing abdominal aortic surgery.
The pharmacokinetics of alfentanil, 300 micrograms.kg-1 IV, were determined in patients undergoing elective abdominal aortic reconstruction. The mean age (+/- SD) of the patients was 64.3 +/- 7.4 yr; their mean weight was 74.7 +/- 13.8 kg. Five patients underwent aneurysm repair and six had aortobifemoral grafting. Serum alfentanil concentrations were measured by gas-liquid chromatography in samples drawn at increasing intervals over a 24-hr period. A three-compartment model was fitted to the concentration versus time data. The volume of the central compartment and the volume of distribution at steady state (Vdss) were 0.44 +/- 0.022 and 0.63 +/- 0.32 L.kg-1, respectively. Total drug clearance was 6.4 = 1.9 ml.min-1.kg-1. The elimination half-time was 3.7 +/- 2.6 hr. Patient age was positively correlated with both Vdss and elimination half-time. There were no significant correlations between the pharmacokinetic variables and the duration of aortic cross-clamping, the duration of surgery, or the rate or total volume of IV fluids infused intraoperatively. In general surgical patients, the elimination half-time of alfentanil has been reported to be 1.2-2.0 hr. Although the elimination half-time of alfentanil was longer in patients undergoing abdominal aortic surgery, alfentanil was eliminated much faster than either fentanyl or sufentanil in this patient population.
Hudson
R J
RJ
Department of Anaesthesia, University of Manitoba, Winnipeg, Canada.
Thomson
I R
IR
Burgess
P M
PM
Rosenbloom
M
M
D000367:Age Factors; D000368:Aged; D015760:Alfentanil / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D000771:Anesthesia, Intravenous; D001012:Aorta, Abdominal / Q000601:surgery*; D001014:Aortic Aneurysm / Q000601:surgery; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D006207:Half-Life; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D012044:Regression Analysis; D013997:Time Factors
D015760:Alfentanil