Mastectomy pain blocks: A comparison of preoperative versus intraoperative pectoralis nerve blocks: Mastectomy pectoralis nerve blocks comparison.

BACKGROUND

Pectoralis nerve blocks (PNB) are increasingly used for post-mastectomy analgesia. We evaluated whether block timing (preoperative vs intraoperative) affected postoperative opioid use.

METHODS

A retrospective review of mastectomy patients receiving preoperative (PPNB) or intraoperative (IPNB) PNB was performed. Multivariable analysis assessed post-anesthesia care unit (PACU) opioid use and morphine milligram equivalents (MME). Subgroup analyses of unilateral (UM) and bilateral mastectomy (BM) were conducted.

RESULTS

Among 122 patients, 69 received PPNB and 53 IPNB. No block-related complications occurred. Overall, 36.1% required no postoperative opioids. Block timing was not associated with differences in PACU opioid use or MME on multivariable analysis, including UM and BM subgroups. Preoperative acetaminophen was independently associated with reduced opioid use and lower MME.

CONCLUSION

PNBs are safe and effective for multimodal mastectomy analgesia. Block timing did not influence opioid requirements, suggesting timing may be guided by workflow, while multimodal strategies remain critical.