Intrathecal morphine for postoperative pain control following robot-assisted prostatectomy: a prospective randomized trial

Robot-assisted laparoscopic prostatectomy (RALP) is minimally invasive surgery, but also causes moderate to severe pain during the immediate postoperative period. We evaluated the efficacy and safety of intrathecal morphine (ITM) for postoperative pain control in patients undergoing RALP. Thirty patients scheduled for RALP were randomly assigned into one of two groups. In the ITM group (n = 15), postoperative pain was managed using 300 A mu g intrathecal morphine with intravenous patient-controlled analgesia (IV-PCA). In the IV-PCA group (n = 15), only intravenous patient-controlled analgesia was used. The numerical pain score (NPS; 0 = no pain, 100 = worst pain imaginable), postoperative IV-PCA requirements and opioid-related complications including nausea, vomiting, dizziness, headache and pruritus were compared between the two groups. The NPSs on coughing were 20 (IQR 10-50) in the ITM group and 60 (IQR 40-80) in the IV-PCA group at postoperative 24 h (p = 0.001). The NPSs were significantly lower in the ITM group up to postoperative 24 h. The ITM group showed less morphine consumption at postoperative 24 h in the ITM group than in the IV-PCA group [5 (IQR 3-15) mg vs 17 (IQR 11-24) mg, p = 0.001]. Complications associated with morphine were comparable between the two groups and respiratory depression was not reported in either group. Intrathecal morphine provided more satisfactory analgesia without serious complications during the early postoperative period in patients undergoing RALP.