Background and Aims We aimed to compare the postoperative pain scores, opioid consumption, and systemic effects of Transversus Abdominis Plan (TAP) block with morphine added as an adjuvant and TAP block and morphine administered intramuscularly for postoperative analgesia in gynecological surgery.

Methods This prospective, double-blind, randomized controlled trial included 52 patients (26 each in the intramuscular (IM) and TAP groups). In the intramuscular (IM) group, 0.1 mg/kg morphine was administered intramuscularly according to the ideal body weight, and ultrasound-guided TAP block was performed bilaterally with 40 mL of 0.25% bupivacaine. In the TAP group, ultrasound-guided TAP block, including 40 mL of 0.25% bupivacaine and 0.1 mg/kg morphine according to the ideal body weight of patients, was administered bilaterally

Results The total 24-hour morphine consumption was lower in the TAP groups. The morphine consumption after 6, 12, and 24 hours was lower in the TAP group than in the control group (p = 0.033, p = 0.003, and p = 0.008, respectively). The VAS scores at rest and during movement did not differ between the two groups. The total 24-hour ondansetron consumption was higher in the IM group (p = 0.046). The postoperative heart rates, blood pressure, and peripheral oxygen saturation at 0, 1, 6, 12, 24 hours did not differ significantly between the groups.

Conclusions The addition of morphine to the TAP block may be an effective method for postoperative analgesia in gynecologic surgery and may not increase systemic side effects.