Effects of Transverse Abdominis Plane Block with Ropivacaine-Hydromorphone versus. Ropivacaine in Cesarean Section: A Randomized Controlled Trial

Objective: To compare the efficacy and safety of ultrasound-guided transverse abdominis plane block (TAPB) with ropivacaine combined with hydromorphone versus ropivacaine alone for postoperative analgesia in parturients undergoing cesarean section. Methods: A randomized controlled trial was conducted with 90 eligible parturients scheduled for elective cesarean section. They were randomly assigned to the experimental group (Group R+H, n=45) receiving TAPB with 0.25% ropivacaine plus 0.2 mg hydromorphone (20 mL per side), and the control group (Group R, n=45) receiving TAPB with 0.25% ropivacaine. The primary outcome was the time to first rescue analgesia. Secondary outcomes included serum prolactin (PRL) levels, pain intensity, patient-controlled analgesia (PCA) usage, postoperative recovery indicators, adverse reactions, and patient satisfaction. Results: The time to first PCA use was significantly longer in Group R+H than in Group R (7.32± 4.80 h vs. 3.49± 1.74 h, p 0.05). Patient satisfaction with analgesia was significantly higher in Group R+H (9 (9, 10) vs. 8 (8, 9), p =0.004). Conclusion: Ultrasound-guided TAPB with ropivacaine combined with hydromorphone provides superior early postoperative analgesia, reduces rescue analgesic requirements, and improves patient satisfaction in parturients undergoing cesarean section. It does not affect perioperative PRL levels or postoperative recovery, nor does it increase adverse events, making it a safe and effective analgesic strategy. Keywords: postoperative pain, ultrasound-guided TAPB, hydromorphone, cesarean section