Effects of erector spinae plane block on postoperative pain in patients undergoing implant-based breast reconstruction for breast cancer: a randomized controlled trial

Abstract

Abstract Background Implant-based breast reconstruction after mastectomy causes acute pain. Objective To determine whether a single-shot T5 erector spinae plane block (ESPB) reduces postoperative pain. Design Single-center, RCT with allocation concealment; blinded assessors and statisticians. Setting Tertiary cancer center in China. Patients 100 adults scheduled for radical mastectomy with implant reconstruction were randomized (1:1); follow-up complete. Intervention Before induction, ESPB was given under ultrasound guidance at T5 with 30 mL of 0.375% ropivacaine plus dexmedetomidine 1 μg/kg; controls received no block. Standardized general anesthesia and postoperative PCA for both groups. Main outcome measures Resting NRS at 6 h (MCID=1). Secondary outcomes were opioid consumption, quality of recovery, and PONV. Results ESPB did not significantly reduce resting pain at 6 h at the median (τ =0.50; adjusted difference −0.9; p = 0.08). At the upper tail, pain intensity was lower (τ = 0.75; −1.8; p <0.01). Repeated measures provided additional time-point information, improving estimation precision and test sensitivity. ESPB get lower pain scores at 6, 12, and 24 hours (all p <0.01). But, the 95% CI includes the MCID, the clinical benefit remains uncertain. Opioid use decreased at 24 h (−13.5 mg; p <0.01) and 48 h (−6.6 mg; p <0.01). Quality of recovery improved at 24 h (difference 5 points; p <0.01), but not later. No differences were observed in intraoperative hemodynamics or PONV. Conclusions Single-shot T5 ESPB with perineural dexmedetomidine may reduce postoperative pain and opioid requirements and improve early recovery. Further large trials are warranted. Clinical relevance remains to be confirmed. Trial registration ClinicalTrials.gov NCT06143020.