Impact of ultrasound-guided rhomboid intercostal and serratus anterior plane blocks on respiratory function after modified radical mastectomy: a randomized controlled trial.

Abstract

Background: This study aimed to evaluate the effectiveness of the rhomboid intercostal plane (RIP) and serratus anterior plane (SAP) blocks at enhancing respiratory function in patients undergoing modified radical mastectomy (MRM).

Methods: Patients were randomly assigned to the block or control group. The block group received RIP and SAP blocks (20 ml 0.25% bupivacaine each), whereas the control group received no block. The primary outcome was forced expiratory volume in one second (FEV₁) 2 h postoperatively. Secondary outcomes included forced vital capacity (FVC), FEV₁/FVC ratio, peak expiratory flow (PEF), forced expiratory flow at 25% to 75% (FEF₂₅₋₇₅), pain scores, and opioid requirements.

Results: The block and control groups had similar FEV1 values (1.80 ± 0.51 vs. 1.74 ± 0.49; P = 0.659) and FEV1/FVC ratios at 2 h. The block group had higher FVC values at 6 h (2.21 ± 0.76 vs. 1.87 ± 0.48; P = 0.034) and 24 h (2.35 ± 0.65 vs. 1.97 ± 0.53; P = 0.014) and higher PEF and FEF25-75 values at 24 h. Pain scores were lower in the block group at all time points, and opioid consumption was higher in the control group during the first 6 h. The incidence of postoperative nausea and vomiting was similar.

Conclusions: This study failed to demonstrate a significant difference in FEV1 values; however, improvements in FVC, PEF, and FEF25-75 indicated a potential positive impact on respiratory function, and combining the RIP and SAP blocks after MRM led to lower pain scores and decreased opioid consumption.