Both clonidine, an alpha(2) agonist, and morphine, an opioid agonist, provide enhanced patient analgesia after arthroscopic knee surgery when administered via the intraarticular (IA) route. Clonidine potentiates morphine analgesia in the animal model. We designed this study to determine whether clonidine or morphine results in better analgesia and whether their combination would provide superior analgesia to either drug alone. We evaluated 60 patients undergoing arthroscopic knee meniscus repair under local anesthesia with sedation. After surgery, patients were randomized into four IA groups: Group B received 30 mL 0.25% bupivacaine; Group BC received 30 mL 0.25% bupivacaine and clonidine 1 microg/kg; Group BM received 30 mL 0.25% bupivacaine and morphine 3 mg; and Group BCM received 30 mL 0.25% bupivacaine, clonidine 1 microg/kg, and morphine 3 mg. This study revealed a significant benefit from the individual IA administration of both clonidine and morphine. The combination of these drugs resulted in decreased postoperative pain and analgesic use, as well as an increased analgesic duration compared with either drug alone. We conclude that IA clonidine and morphine improved comfort compared with either drug alone in patients undergoing knee arthroscopy.

This study was designed to determine whether administration of caudal bupivacaine with fentanyl would have any effect on analgesia in paediatric patients undergoing inguinal herniorrhaphy repair. Fifty-six outpatient paediatric patients undergoing inguinal hernia repair were evaluated. Patients received, in a randomized manner, 1 ml.kg-1 of either bupivacaine 0.25% or 0.125% with or without fentanyl 1 microg.kg-1. There was no difference in pain scores in the hospital, the night of surgery, or 24 h postoperatively nor was there a difference in the oral analgesics administered between any of the groups. There was a higher incidence of vomiting at home in both 0.25% bupivacaine groups irrespective of the use of fentanyl. The 0.125% bupivacaine group had significantly more patients who received intravenous fentanyl in the PACU than did the other three groups (P<0.001). Increasing the concentration of bupivacaine from 0. 125% to 0.25% increased the incidence of postoperative vomiting. We recommend that clinicians utilize bupivacaine 0.125% with 1 microg. kg-1 fentanyl as the caudal injectate in paediatric patients undergoing inguinal hernia repair.