Fentanyl and clonidine as adjunctive analgesics with levobupivacaine in paravertebral analgesia for breast surgery

Abstract
The addition of fentanyl or clonidine to levobupivacaine was evaluated in patients undergoing breast surgery under general anaesthesia with intra- and postoperative paravertebral analgesia. Patients were randomly allocated to four groups: Group L received 19 ml bolus levobupivacaine 0.25% plus 1 ml saline followed by an infusion of levobupivacaine 0.1%; Group LF received 19 ml bolus levobupivacaine 0.25% plus fentanyl 50 microg followed by an infusion of levobupivacaine 0.05% with fentanyl 4 microg x ml(-1); Group LC received 19 ml bolus levobupivacaine 0.25% plus clonidine 150 microg followed by an infusion of levobupivacaine 0.05% with clonidine 3 microg x ml(-1); Group C (control) received general anaesthesia without paravertebral analgesia. All groups received postoperative i.v. morphine patient controlled analgesia (PCA). Although mean (SD) postoperative PCA morphine consumption was decreased in LF [7.9 (4.1) mg] and LC [5.9 (3.5) mg]vs L [27.7 (8.6) mg] or C patients [21.7 (5.5) mg], p < 0.01, paravertebral fentanyl and clonidine were associated with significantly increased vomiting and hypotension, respectively.