title: Epidural bupivacaine for aortic surgery. The effect of dilution on the quality of analgesia.
abstract: Twenty patients undergoing elective abdominal aortic aneurysm repair were randomly allocated to two groups and studied for 24 h following surgery. Postoperative analgesia was provided by epidural bupivacaine infusion and intravenous patient-controlled 0.05 mg boluses of alfentanil. One treatment group received 7 ml.h-1 of a 0.25% solution of bupivacaine, the other 25 ml.h-1 of a 0.07% solution. The rate of infusion was thus 17.5 mg.h-1 in both groups. Patients receiving 7 ml.h-1 of epidural infusate required more doses of alfentanil (median 26.5, range 0-50) than the group receiving 25 ml.h-1 of the dilute infusion (median 3.0, range 0-16). It is concluded that 17.5 mg.h-1 of bupivacaine infused into the epidural space produces better analgesia when infused in a volume of 25 ml.h-1 (0.07%) than when given in a volume of 7 ml.h-1 of solution (0.25%).
authors.affiliation: Department of Anaesthetics, Poole General Hospital, Dorset.
authors.forename: J M
authors.initials: JM
authors.lastname: Slade
mesh_terms: D000368:Aged; D015760:Alfentanil / Q000008:administration & dosage; D015360:Analgesia, Epidural / Q000379:methods*; D016058:Analgesia, Patient-Controlled; D001012:Aorta, Abdominal / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D002045:Bupivacaine; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*
chemical_list: D015760:Alfentanil; D002045:Bupivacaine