Intrathecal morphine (ITM) provides effective postoperative cesarean delivery analgesia but has not been reported for postoperative postpartum tubal ligation (PPTL) analgesia. We designed this prospective, randomized, double-blinded study to determine the efficacy of 100 microg ITM for postoperative PPTL analgesia. Sixty-six women received spinal anesthesia with 60 mg (1.2 mL) of 5% hyperbaric lidocaine, 10 microg (0.2 mL) of fentanyl, and either 0.2 mL of 0.9% saline (normal saline; NS) or 100 microg (0.2 mL) of morphine (morphine sulfate, MS). Postoperative analgesia was limited to patient-controlled IV analgesia morphine. Six women (three NS and three MS) were excluded because of major protocol violations. Twenty-four-hour patient-controlled IV analgesia morphine use was (mean +/- SD) 39.6 +/- 19.6 mg in the NS group and 1.1 +/- 2.5 mg in the MS group (P < 0.0000001). Visual analog scale scores for crampy and incisional pain (rest and movement) were significantly higher in the NS group compared with the MS group at 4, 8, 12, and 24 h (P < 0.001). The adverse effect profile was similar between groups. Visual analog scale satisfaction scores (mean +/- SD) were 96.6 +/- 16.0 in the MS group and 84.2 +/- 23.6 in NS group (P < 0.05). The results of this study indicate that women experience significant postoperative pain after PPTL surgery, and this pain is effectively obviated by 100 microg ITM.
Implications: This investigation documents the extent of the significant postoperative pain experienced by women after routine postpartum tubal ligation surgery and demonstrates the efficacy of a small dose (100 microg) of intrathecal morphine to obviate this pain with minimal adverse effects.