Regional anesthesia in breast surgery: An Italian expert consensus – Part 1: Methodology and Delphi strategy

Background: Despite being considered routine, breast surgery is associated with a high incidence of acute and chronic postoperative pain, which can significantly impact recovery and quality of life. Regional anesthesia techniques have become increasingly relevant within multimodal analgesic strategies, yet clinical practice remains heterogeneous and lacks clear guidance. To address this, we aimed to develop a multidisciplinary, evidence-based consensus on the role of regional anesthesia in breast surgery. Methods: An expert panel was appointed by the Italian Chapter of the European Society of Regional Anaesthesia, including anesthesiologists and breast surgeons (in partnership with the Italian National Association of Breast Surgeons). A four-round Delphi method was applied to refine an initial set of 24 PICO-formulated questions. Each question was evaluated for relevance and clarity using a 9-point Likert scale (1 = not relevant/clear, 9 = extremely relevant/clear). Finalized questions underwent systematic review or network meta-analysis depending on data availability. Results: Eleven clinically relevant and clearly formulated PICO questions were identified after four Delphi rounds. These questions encompass acute and chronic pain control, block safety in anticoagulated patients, awake surgery, and the comparative efficacy of single-shot versus continuous blocks, among others. Each question will guide a systematic review and support the development of graded consensus statements. Conclusion: This consensus project establishes a transparent, multidisciplinary framework for guiding the use of regional anesthesia in breast surgery. The ultimate objective is to formulate a set of consensus statements, graded according to evidence strength, which will serve as a foundation for future guidelines and standardized clinical decision-making.