Continuous wound infusion as a valid alternative to tap block for postoperative analgesia after abdominal hysterectomy: A randomized controlled trial

Background: Total abdominal hysterectomy is a procedure associated with moderate to severe postoperative pain. Regional anesthesia techniques, such as fascial plane blocks, have shown promise in improving postoperative pain control. While continuous wound infusion is recommended for cesarean section, it is not recommended for open abdominal hysterectomy. Our aim is to compare surgically placed catheter for wound infusion with the transverse abdominis plane block. Methods: A single-center prospective randomized controlled trial was conducted in Italy from January to July 2023. Patients undergoing elective hysterectomy were randomly assigned to receive either bilateral transverse abdominis plane block or continuous wound infusion. The primary outcome measure was the assessment of static pain in the recovery room and at 6, 12, 24, and 48 hours postoperatively using the numeric rating scale (NRS) for pain. Of the 34 patients assessed for eligibility, 32 were randomized and equally distributed between the continuous wound infusion and transverse abdominis plane block groups. Result: Patients receiving continuous wound infusion consistently reported lower static NRS pain scores compared to those receiving transverse abdominis plane block across all postoperative time points. The median NRS scores were significantly lower in the wound infusion group at 6, 12, 24, and 48 hours post surgery (P < 0.05). Importantly, similar significant differences were also observed between the groups for dynamic NRS scores. However, no significant differences were observed between the groups for secondary outcomes, including nausea and vomiting, and recovery of functional capacity. Conclusion: Continuous wound infusion with a properly positioned catheter is noninferior to transverse abdominis plane block for postoperative pain management following total abdominal hysterectomy and may even provide superior pain control. These findings suggest continuous wound infusion as a viable alternative for effective pain management in total abdominal hysterectomy procedures.