title: Randomized controlled trial of patient-controlled epidural analgesia after orthopaedic surgery with sufentanil and ropivacaine 0.165% or levobupivacaine 0.125%.
abstract: BACKGROUND
  Ropivacaine, and to a lesser extent also levobupivacaine, is commonly used for postoperative epidural analgesia. Despite ED50 data suggesting a potency difference between these drugs, clinically they can be difficult to distinguish. As a consequence, it is unclear which concentration of each drug to use when comparing them for long-term analgesia.
  
  
  METHODS
  One hundred patients undergoing total hip or knee replacement were selected to participate in a double-blind randomized study comparing ropivacaine 0.165% with levobupivacaine 0.125% to which was added sufentanil 1 microg ml(-1) for postoperative analgesia by the epidural route. Patient-controlled epidural analgesia (PCEA) was offered for 48 h. After the first 24 h, the basal infusion was omitted.
  
  
  RESULTS
  Pain scores both at rest and on mobilization were similar between both groups. The volume of local anaesthetic solution consumed during the first 48 h after surgery was 25% higher in those patients receiving ropivacaine (P=0.02). Patients receiving ropivacaine made a mean (SD) of 38.5 (16) PCEA demands in the first 48 h after surgery compared with 28 (13) in the levobupivacaine group (P=0.04).
  
  
  CONCLUSIONS
  Both local anaesthetics provided effective postoperative analgesia but, even in a 25% weaker concentration, a small volume of levobupivacaine and opiate substance was consumed. These differences may be explained by a potency difference or by the duration of action of levobupivacaine.
authors.affiliation: Department of Anaesthesia, Algemeen Ziekenhuis Nikolaas, Sint Niklaas, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: Smet
authors.forename: E
authors.initials: E
authors.lastname: Vlaminck
authors.forename: M
authors.initials: M
authors.lastname: Vercauteren
mesh_terms: D000328:Adult; D000368:Aged; D000577:Amides / Q000008:administration & dosage / Q000009:adverse effects; D015360:Analgesia, Epidural / Q000379:methods*; D016058:Analgesia, Patient-Controlled / Q000379:methods*; D000767:Anesthesia, Epidural; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D002045:Bupivacaine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D006801:Humans; D000077554:Levobupivacaine; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000517:prevention & control*; D000077212:Ropivacaine; D017409:Sufentanil / Q000008:administration & dosage
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D004338:Drug Combinations; D000077212:Ropivacaine; D000077554:Levobupivacaine; D017409:Sufentanil; D002045:Bupivacaine