An observational study evaluating the perioperative efficacy of the Pectoralis nerve blocks I and II

Abstract

Background Poorly managed perioperative mastectomy pain increases the incidence of chronic pain. The postoperative risk factor for developing chronic pain identified was severe acute postoperative pain. This presents the perioperative team with a variable that can be modified with regional anaesthesia to improve outcomes. The aim of this study is to determine the analgesic efficacy of PEC I & II blocks versus the administration of local anaesthesia via a surgical drain in post-mastectomy patients. These techniques were compared with regards to postoperative pain scores, satisfaction, time to first request for systemic opioid postoperatively, opioid consumption, the incidence of postoperative nausea and vomiting (PONV) and complications. Methods A prospective, contextual, cohort, observational, single centre study with 30 female participants who were recruited via convenience sampling. Participants were assigned to PEC blocks (Group P, n=15) or local anaesthesia via surgical drain (Group S, n=15). The general anaesthesia was standardized between the groups. Group S received the standard of care which was administration of 2mg/kg of 0.5% bupivacaine with adrenaline (1:200,000) via the surgical drain. Group P received 0.2ml/kg of 0.5% bupivacaine plus adrenaline (1:200,000) in each fascial plane. Results There were no significant differences in participants’ characteristics in the groups. The study showed no statistically significant difference between the pain scores of the groups at 30 minutes, 3, 6, and 24 hours postoperatively (p=0.660, p=0.160, p=0.894, p=0.931). The differences in patient satisfaction scores and morphine consumption were statistically insignificant. No complications were noted in either of the groups. No statistically significant relationship with the occurrence of vomiting and nausea and the specific technique. Conclusion The techniques evaluated in this study demonstrate a similar efficacy in the management of postoperative pain in mastectomy patients. The techniques can be considered safe as there is a low incidence of the described complications including the incidence of PONV.