Ultrasound-guided Double-point Versus Single-point Serratus Anterior Plane Block for Modified Radical Mastectomy: A Randomized Controlled Trial.

Abstract

The double-point serratus anterior plane block(SAPB) covers more area, including the axilla, than the single-point approach, potentially offering better pain relief after Modified radical mastectomy(MRM). Sixty women were randomly assigned to double or single-point groups. Double-point received SAPB at the third and fifth ribs, single-point at the fifth rib. Primary outcome: pain numeric rating scale (NRS) at rest and movement 24 hours post-surgery. Secondary outcomes: axilla comfort NRS, recovery quality, and adverse events. At 24 hours post-surgery, the double-point group compared to the single-point group showed movement pain NRS of 3 (2-3) vs. 3 (3-4) (P = 0.011) and rest pain NRS of 1 (1-1) vs. 2 (1-3) (P = 0.037). The difference between them did not exceed the MCID. The axillary comfort NRS in the double-point group was lower than the single-point group at 6 and 12 hours post-surgery, at 1 (1-2) vs. 2 (2-4) (P=0.001) and 1 (1-2) vs. 2 (2-4) (P=0.01) respectively, but there was no difference at 24 and 48 hours post-surgery. At 48 hours post-surgery, pain scores and opioid use were similar in both groups. Recovery scores, rescue analgesia timing, adverse events, and hospital stay length were similar in both groups. Double-point SAPB offers wider anesthetic spread but shows no significant clinical advantage in pain or axillary comfort over single-point SAPB after MRM.