Evaluation of Rhomboid Intercostal and Subserratus Plane Block Under Direct Vision For Postoperative Analgesia in Thoracic Surgeries: A Prospective, Randomized Controlled Trial.

OBJECTIVES: This study is designed to evaluate the efficacy of rhomboid intercostal and subserratus plane (RISS) block under the surgeon's direct vision for providing postoperative pain relief after thoracic surgeries.

METHODS: Forty patients who underwent thoracotomy were prospectively recruited and randomly assigned to group R (intravenous patient-controlled analgesia (IVPCA)+continued RISS block; n = 20) and group C (IVPCA; n = 20). Numeric rating scale (NRS) at rest and cough, at post-anesthetic care unit, 1, 2, 6, 9, 12, 24, and 48 hours was used as the primary outcome measure. Secondary outcome measures were the amount of tramadol consumption, the number of patients required rescue analgesia, the occurrence of postoperative adverse effects, pulmonary functions, and the overall satisfaction with pain management.

RESULTS: NRS scores both at rest and during coughing were significantly lower in group R than the group C group at all time intervals (p < 0.001 in each). Tramadol consumption at 24 h and 48 h was significantly lower in the group R block than group C (p < 0.001 for each). None of the patients in group R require rescue analgesia. The incidence of nausea and vomiting was similar among the groups. Compared with group C, change in lung function from baseline levels was significantly less in group R (p = 0.047 and p = 0.04 for FEV1 and FVC, respectively). The satisfaction scores in group R were significantly higher than group C (p < 0.001).

CONCLUSION: Continuous RISS block improved postoperative outcomes of thoracic surgery in terms of reduced postoperative pain scores, sparing opioid consumption, pulmonary function, and patient satisfaction.

CLINICAL TRIAL REGISTRATION: NCT04443556 (https://clinicaltrials.gov/ct2/show/NCT04443556).