Randomized, controlled trial comparing the efficacy of intercostal nerve block in thoracoscopic surgery by timing: study protocol for a randomized clinical trial.

Abstract

Background: Even minimally invasive thoracic surgeries carry a postoperative cost in pain. While regional anesthesia may alleviate this anticipated pain, especially intercostal nerve blocks (ICNB), the timing of block administration for optimal effect (at the beginning of surgery vs. before wound closure) remains controversial. Here, we plan (1) to test the hypothesis that performing ICNB at the beginning of surgery provides superior postoperative analgesic effects compared to before wound closure and (2) to observe perioperative outcomes to determine whether the timing affects acute and chronic postoperative pain, or intraoperative patient management.

Methods: This single-blinded, single-center, randomized, controlled trial will be conducted at the Department of Thoracic Surgery, University of Tsukuba Hospital from Sep 29, 2024, to June 30, 2026. Patients 16-79 years old within the regular population of patients undergoing lung wedge resection via video-assisted thoracoscopic surgery (VATS) without a utility window approach and who are ASA-PS classes 1-3 will be enrolled to receive ICNB either pre-operatively or before wound closure. Groups will be single-blinded (patient only) at random, and the primary outcome will be assessment by Numerical Rating Scale (NRS) pain scores during movement, measured 4 h after returning to the ward. Secondary outcomes will be (1) any additional analgesic use within the 4-h return window, (2) intraoperative measurements (including amounts of remifentanil used, time from surgery completion to extubation, occurrence of shivering or nausea after extubation, use of antiemetics, and maximum blood pressure/heart rate), (3) acute pain during hospitalization (using routinely administered NRS), (4) postoperative analgesic use, and (5) quality of life (QOL) scores on EQ-5D and SF-36 questionnaires at preoperative and 3-month postoperative timepoints. Chronic pain at 3 months post-surgery will also be determined by NRS.

Discussion: A complete evaluation of ICNB efficacy as a preemptive analgesic approach will contribute to the development of improved perioperative pain management techniques. A reduction in the duration of surgery-related symptoms and an improvement in postoperative QOL will be the result.

Trial registration: Japan Registry of Clinical Trials: identifier jRCT1031240358. Registered on 29 Sep 2024.  https://jrct.niph.go.jp/latest-detail/jRCT1031240358 .