Efficacy of ultrasound-guided bilateral rectus sheath block vs. local anesthetic infiltration in gynecologic oncology patients undergoing midline laparotomy: a triple-blinded randomized controlled trial.

Background: Postoperative pain is a serious problem in gynecological oncology patients. Rectus sheath block (RSB) is increasingly utilized as a part of multimodal analgesia. The purpose of this three blinded, randomized-controlled trial is to compare the analgesic efficacy of ultrasound-guided (US-guided) bilateral rectus sheath block (BRSB) and local anesthetic wound infiltration (LAWI) application in patients undergoing midline laparotomy for gynecologic cancer.

Methods: This prospective, single-center, three-blinded, randomized clinical trial enrolled a total of 60 patients who underwent surgery through a midline laparotomy. Patients were randomly allocated into two groups and were administered either LAWI or BRSB with 20 mL of 0.25% bupivacaine just after the end of surgery. Both groups were compared for Numeric Rating Scale (NRS) pain scores, time to first analgesic requirement, total tramadol consumption.

Results: Fifty-five patients (BRSB=28, LAWI=27) completed the study. The BRSB group had significantly lower NRS scores at 2, 6, 12, and 24th hours (P<0.001). The median (interquartile range, IQR) NRS scores for BRSB group were 3 (3-3) at 2nd hours, 3 (2-4) at 6th hours, 3 (2-4) at 12th hours and 3 (2-3) at 24th hours. For the LAWI group, the median (IQR) NRS scores were 4 (3-4) at 2nd hours, 4 (3-5) at 6th hours, 4 (3-4) at 12th hours and 4 (3-4) at 24th hours. The BRSB group had significantly less additional tramadol consumption than the LAWI group (P<0.001).

Conclusions: The US-guided BRSB is a safe and feasible technique. This technique resulted in reduced postoperative pain scores, decreased tramadol usage, and prolonged pain relief compared to LAWI.