title: Postoperative epidural infusion: a randomized, double-blind, dose-finding trial of clonidine in combination with bupivacaine and fentanyl.
abstract: The aim of this randomized, double-blind trial of postoperative thoracic epidural analgesic infusions was to determine whether clonidine at 10 microg/h (group C10, n = 22), 15 microg/h (Group C15, n = 24), or 20 microg/h (Group C20, n = 24) improved postoperative analgesia in patients undergoing abdominal gynecologic surgery, without side effects or hemodynamic changes, when added to a 5-mL/h infusion of 0.125% bupivacaine and fentanyl 2 microg/mL (Group CO, n = 22). The 24-h study infusion was supplemented, as required, by patient-controlled epidural fentanyl. Groups were similar for age, weight, duration, and type of surgery. Clonidine produced a dose-dependent improvement in analgesia at rest. Only 20 microg/h significantly increased the percentage of patients who experienced no pain with coughing (relative risk 1.44, 95% confidence interval 1.24-1.94), reduced pain scores with coughing (P < 0.05), and significantly lowered supplementary fentanyl requirements (P < 0.05). Groups were similar for sedation, pruritus, nausea, time to ambulation, and satisfaction with analgesia. Clonidine produced a dose-dependent decrease in blood pressure and pulse rate and an increase in vasopressor requirement (P < 0.01). Epidural clonidine infused at 20 microg/h improves analgesia during coughing when combined with epidural bupivacaine-fentanyl in patients undergoing lower abdominal surgery but is associated with hemodynamic changes and increased vasopressor requirement.
authors.affiliation: Department of Anaesthesia, King Edward Memorial Hospital for Women, Western Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Paech
authors.forename: T J
authors.initials: TJ
authors.lastname: Pavy
authors.forename: C E
authors.initials: CE
authors.lastname: Orlikowski
authors.forename: W
authors.initials: W
authors.lastname: Lim
authors.forename: S F
authors.initials: SF
authors.lastname: Evans
mesh_terms: D000316:Adrenergic alpha-Agonists; D000328:Adult; D015360:Analgesia, Epidural / Q000379:methods*; D016058:Analgesia, Patient-Controlled; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D002045:Bupivacaine; D003000:Clonidine; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D010149:Postoperative Pain / Q000188:drug therapy
chemical_list: D000316:Adrenergic alpha-Agonists; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D003000:Clonidine; D005283:Fentanyl; D002045:Bupivacaine