Comparison of posterior transversus abdominis plane block and erector spinae plane block for postoperative analgesia after caesarean section performed under spinal anesthesia: a prospective randomized trial.

BACKGROUND

This study aimed to compare the analgesic efficacy of the transversus abdominis plane block (TAPB) and the erector spinae plane block (ESPB) following cesarean delivery under spinal anesthesia. The primary endpoint was the proportion of patients requiring rescue analgesia within the first 24 hours postoperatively. Secondary outcomes included time to first rescue analgesia, Numerical Rating Scale (NRS) scores at predefined time points (30 minutes, 4, 8, 12, 16, and 24 hours), and the incidence of persistent postsurgical pain at two months.

METHODS

This single-center, prospective, randomized controlled study included patients undergoing cesarean section under spinal anesthesia. Participants were randomly allocated into two groups: TAPB and ESPB. Postoperative pain and vital signs were assessed 30 minutes after block application and at 4, 8, 12, 16, and 24 hours postoperatively. Pain intensity was measured using the NRS (0=no pain, 10=worst imaginable pain). Rescue analgesia was administered when the NRS score was ≥4. Diclofenac sodium 75 mg intramuscularly (IM) was given for NRS scores of 4-5, while intravenous (IV) morphine sulfate 0.05 mg/kg was administered for NRS scores ≥6.

RESULTS

A total of 94 patients were analyzed: 48 received ESPB and 46 received TAPB postoperatively. The TAPB group had a significantly higher proportion of patients requiring rescue nonsteroidal anti-inflammatory drug (NSAID) analgesics compared to the ESPB group (58.70% vs. 27.08%, p=0.002). NRS scores at 30 minutes, 12 hours, and 16 hours postoperatively were significantly lower in the ESPB group (p=0.03, p=0.003, and p=0.023, respectively).

CONCLUSION

For postoperative analgesia following cesarean section under spinal anesthesia, ESPB resulted in a significantly lower proportion of patients requiring rescue analgesia within the first 24 hours compared to TAPB. In addition, ESPB demonstrated a faster onset and longer duration of effective analgesia, suggesting it may be a more favorable option for postoperative pain management in this clinical setting.