Evaluating The Efficacy Of Pecs II Blockade Compared To Local Anesthetic Infiltration In Controlling Postoperative Pain In Patients Undergoing Oncologic Breast Surgery Under Opioid Free/Sparing Anesthesia.

Introduction: Breast cancer is the most prevalent malignant neoplasm among women in Brazil, and oncologic surgery is an essential part of its treatment. Postoperative pain is a significant challenge, especially in approaches with general anesthesia. Methods such as PECS II blockade and infiltration of local anesthetics have been used for pain management and reduction of opioid consumption. Objective: The study aims to evaluate the effectiveness of the PECS II interfascial block in comparison with local anesthetic infiltration in controlling postoperative pain in patients undergoing breast oncology surgery under general anesthesia with minimal use of opioids (opioid-free/sparing). Methodology: This is a prospective, randomized, double-blind clinical trial involving 133 patients. They will be divided into two groups: PEC group: will receive the PECS II block; LOC group: will be treated with local anesthetic infiltration at the surgical site. Both interventions will take place after induction of anesthesia. The outcomes assessed include postoperative pain (using a visual analog scale - VAS), occurrence of nausea and vomiting (PONV), opioid consumption and side effects during 24 hours after surgery. Conclusion: The study aims to verify which anesthetic group provides less post-operative pain, less opioid consumption and greater patient well-being by not causing vomiting and nausea.