The Efficacy of Intrathecal Morphine With or Without Clonidine for Postoperative Analgesia After Radical Prostatectomy

BACKGROUND: In this randomized study, we compared intrathecal (IT) morphine with or without clonidine and IV postoperative patient-controlled analgesia (PCA) morphine for analgesia after radical retropubic prostatectomy. METHODS: Fifty patients were randomly divided into three groups. They were allocated to receive IT morphine (4 mu g/kg) (M group), IT morphine and clonidine (1 mu g/kg) (MC group), or PCA (PCA group). Each patient was given morphine PCA for postoperative analgesia. The primary objective was the quantity of morphine required during the first 48 postoperative hours. The first request for morphine, numeric pain score at rest and on coughing, the time of tracheal decannulation and adverse effects (pruritus, postoperative nausea and vomiting, respiratory depression) were recorded. RESULTS: Morphine consumption in the first 48 h was decreased in the M and MC groups. The numeric pain score at rest and on coughing were lower in the M group until the 18th postoperative hour and until the 24th postoperative hour in the MC group. The first requests for PCA were delayed in these two groups. The need for intraoperative sufentanil was significantly lower in the MC group. CONCLUSION: IT morphine provided a significant reduction in morphine requirement during the first 48 postoperative hours after a radical prostatectomy. The addition of clonidine to IT morphine reduced intraoperative sufentanil use, prolonged time until first request for PCA rescue, and further prolonged analgesia at rest and with coughing. (Anesth Analg 2009:108:1954-7)