Analgesic effects of combined transversus abdominis plane block and intramuscular electrical stimulation in patients undergoing cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy: a randomized controlled trial

Background: To evaluate the analgesic efficacy of a four-quadrant transversus abdominis plane (4QTAP) block and a combination of 4QTAP block with needle electrical twitch and intramuscular electrical stimulation (NETOIMS) in patients undergoing cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC). Materials and Methods: Eighty-one patients who underwent CRS followed by HIPEC were included in this study. Patients were randomly assigned to one of three groups: group 1 (intravenous patient-controlled analgesia, control group), group 2 (preoperative 4QTAP block), and group 3 (preoperative 4QTAP block and postoperative NETOIMS). The primary study endpoint was the pain score assessed by the visual analog scale (VAS: 0, no pain; 10, worst imaginable pain) on postoperative day (POD) 1. Results: The VAS pain score on POD 1 was significantly lower in group 2 than in group 1 (6.0 +/- 1.7 and 7.6 +/- 1.9, P = 0.004), whereas that in group 3 was significantly lower than that in groups 1 and 2 (P < 0.001 and P = 0.004, respectively). Opioid consumption and nausea and vomiting incidence during POD 7 were significantly lower in group 3 than in groups 1 and 2. Gait speed and peak cough flow on POD 4 and 7, as well as the quality of recovery (QoR)-40 score on POD 4, were significantly higher in group 3 than in groups 1 and 2. Conclusions: The combination of a 4QTAP block with NETOIMS provided more effective analgesia than a 4QTAP block alone after CRS, followed by HIPEC, and enhanced functional restoration and quality of recovery.