Effect of Bilateral Rhomboid Intercostal Block on Postoperative Pain After Breast Implant Surgery

This prospective, randomized, single-center, single-blind clinical study is designed to evaluate the postoperative analgesic efficacy of bilateral Rhomboid Intercostal Block (RIB) in patients undergoing elective bilateral breast prosthesis surgery.

Patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status I-II who are scheduled for elective bilateral breast prosthesis surgery will be screened for eligibility. After obtaining written informed consent, participants will be randomly allocated into two groups using a computer-generated randomization sequence.

Group RIB: Patients will receive ultrasound-guided bilateral Rhomboid Intercostal Block in addition to standardized general anesthesia.

Control Group: Patients will undergo surgery under standardized general anesthesia without any regional block intervention.

The RIB procedure will be performed under aseptic conditions using ultrasound guidance. For each side, a total volume of 30 mL local anesthetic solution will be administered. The solution will consist of 5 mL of 2% lidocaine, 10 mL of 0.25% bupivacaine, and 15 mL of 0.9% sodium chloride, ensuring that maximum safe dosage limits are not exceeded.

All patients will receive a standardized general anesthesia protocol. Postoperative analgesia will be provided using intravenous tramadol via patient-controlled analgesia (PCA). Tramadol dosing will be calculated according to body weight, with a reference dose of 0.1 mg/kg. The PCA bolus dose will be set at one-quarter of this reference dose, and the hourly maximum limit will be set at twelve times the bolus dose.

Postoperative assessments will be conducted at 0, 1, 2, 6, 12, and 24 hours. Pain intensity will be measured using a validated Visual Analog Scale (VAS) or Numeric Rating Scale (NRS). Rescue analgesia will be administered when pain scores are ≥4, and additional analgesic consumption will be recorded.

The primary endpoint is total tramadol consumption within the first 24 postoperative hours. Secondary endpoints include pain scores at predefined time points, time to first analgesic requirement, need for rescue analgesia, incidence of postoperative nausea and vomiting, analgesia-related adverse effects, and block-related complications.

Data will be analyzed using appropriate statistical methods. The study will be conducted in accordance with ethical principles and will commence after approval from the institutional ethics committee.

Inclusion criteria

• Female patients aged 18-65 years
• American Society of Anesthesiologists (ASA) physical status I-II
• Scheduled for elective bilateral breast prosthesis surgery
• Ability to understand the study protocol and provide written informed consent

Exclusion criteria

• Refusal to participate
• Known allergy or hypersensitivity to local anesthetics (lidocaine or bupivacaine) or tramadol
• Coagulation disorders or current anticoagulant therapy
• Infection at the injection site
• Chronic opioid use or chronic pain syndromes
• Severe hepatic, renal, or cardiac disease
• Neurological or psychiatric conditions interfering with pain assessment
• Body mass index (BMI) > 35 kg/m²
• Pregnancy or breastfeeding