Alfentanil-oxygen anaesthesia: plasma concentrations and clinical effects during variable-rate continuous infusion for coronary artery surgery.
A variable rate continuous infusion of alfentanil 12.5-50 mg h-1, commenced after tracheal intubation, was used as the sole opioid anaesthetic agent in 14 patients undergoing coronary artery surgery. The infusion rate was adjusted to somatic responses and to maintain a stable systolic arterial pressure. Plasma alfentanil concentrations were determined throughout anaesthesia, including peaks of surgical stress and for 5 h after operation. Before cardiopulmonary bypass (CPB), a mean infusion rate of 36.6 +/- 8.9 mg h-1 minimized the frequency of hypertensive episodes and resulted in high plasma alfentanil concentrations which reached a mean peak, 1.76 +/- 0.46 micrograms ml-1 at maximal sternal spread. After CPB, a slower infusion rate, 6.9 +/- 5.8 mg h-1, afforded cardiovascular stability. Patients recovered consciousness 3.1 +/- 1.4 h after operation at a mean plasma alfentanil concentration of 0.27 +/- 0.13 micrograms ml-1. Apart from clinical response, parameters have not yet been identified which may optimize infusion rates.
D015760:Alfentanil; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D004334:Drug Administration Schedule; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007263:Infusions, Parenteral; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010100:Oxygen; D012121:Respiration, Artificial
D015760:Alfentanil; D010100:Oxygen; D005283:Fentanyl