This study aimed to compare the effectiveness of preoperative PECS I block and intraoperative local anesthetic infiltration in managing postoperative pain following breast augmentation surgery. The primary focus was to evaluate their impact on postoperative pain levels, perioperative remifentanil and postoperative opioid consumption and opioid-related side effects during the early recovery period.

Breast augmentation is one of the most performed procedures in aesthetic surgery worldwide.These techniques, which involve muscle dissection and manipulation, tend to be more painful compared to subglandular and subfascial placements. Thus, managing postoperative pain effectively becomes a critical aspect of patient recovery and satisfaction.

To address postoperative pain in breast augmentation, various techniques, including regional anesthesia such as pectoral nerve blocks, local anesthetic infiltration, and pocket irrigation, are employed.

This study aimed to compare the effectiveness of preoperative PECS I block and intraoperative local anesthetic infiltration in managing postoperative pain following breast augmentation surgery. The primary focus was to evaluate their impact on postoperative pain levels, perioperative remifentanil and postoperative opioid consumption and opioid-related side effects during the early recovery period.

This prospective, double-blind, split-body design study was conducted at Yeditepe University Faculty of Medicine, Plastic, Reconstructive, and Aesthetic Surgery Department, in collaboration with the Anesthesiology and Reanimation Department.

The anesthesia induction and PECS I blocks for the right breasts were performed by the same anesthesiologist in all patients (O.K.). Breast augmentation surgeries and local anesthetic infiltrations for the left breasts were performed by the same plastic surgeon (M.E.). Postoperative pain assessments were conducted by a different anesthesiologist who was blinded to the study design.

Postoperative pain was assessed using the Numeric Rating Scale (NRS), ranging from "0 = no pain" to "10 = unbearable pain." Pain assessments were performed every 30 minutes for the first 2 hours, every 2 hours between 2 and 6 hours, and at the 24ᵗʰ hour postoperatively.

Inclusion Criteria:

• Female participants aged 18 to 59 years.
• ASA (American Society of Anesthesiologists) physical status I or II.
• Scheduled for primary breast augmentation surgery using a dual-plane or submuscular approach.
• Planned to receive silicone implants of identical volume and shape for both breasts.
• Able to provide written informed consent.
• Willing and able to comply with study procedures and follow-up assessments.

Exclusion Criteria:

• Planned subglandular or subfascial breast augmentation.
• Undergoing revision breast surgery.
• History of breast disease, previous breast or axillary surgery, or breast cancer.
• Preoperative breast pain or chronic pain syndromes (e.g., fibromyalgia, chronic headaches, back pain, complex regional pain syndrome, neuropathic pain, osteoarthritis, or radicular pain).
• BIRADS score > 3 based on imaging (ultrasound/mammography) within the past year.
• Allergy to medications used in the study (e.g., bupivacaine, propofol, fentanyl, sevoflurane, cefazolin, paracetamol, ondansetron, tramadol, or morphine HCl).
• Coagulopathy or bleeding disorders.
• Pregnant or at risk of pregnancy.
• Inability to provide informed consent or communication difficulties.
• Significant medical conditions that may interfere with the study outcomes.

Participation in this study is limited to self-identified women who are biologically female (cisgender women). Individuals whose self-identified gender does not align with their biological sex (e.g., transgender men, transgender women, or nonbinary individuals) are not eligible for this study. This criterion ensures consistency in evaluating outcomes related to breast augmentation surgery in a biologically female population.

The following specific individual participant data (IPD) will be shared:

De-identified Participant Data:

Demographic data (age, BMI, ASA classification). Pain scores measured using the Numeric Rating Scale (NRS) at predefined intervals.

Postoperative opioid consumption (tramadol and morphine requirements). Incidence of postoperative complications (e.g., sensory changes, wound dehiscence).

Data Dictionary:

A comprehensive guide explaining the variables and coding used in the dataset to ensure accurate interpretation by other researchers.

Exclusions:

Personally identifiable information (e.g., names, contact information) will not be shared to maintain participant confidentiality.

The data will be shared after the study is completed, analyzed, and the results are published in a peer-reviewed journal. Access will be granted only to researchers who provide a justified request and agree to the terms of a formal data-sharing agreement

The data and supporting information will be made available after the study is completed, analyzed, and the results are published in a peer-reviewed journal.

IPD and supporting documents will be shared through a secure online repository or data-sharing platform, accessible only to approved researchers

Researchers must submit a formal data-sharing request, including a detailed explanation of how the data will be used.

A data-sharing agreement must be signed to ensure the ethical use of the shared information, adherence to confidentiality, and compliance with relevant regulations.