Comparison of Erector Spinae Plane Block and Serratus Posterior Superior Intercostal Plane Block in Postoperative Pain Management After Coronary Artery Bypass Grafting

This is a single-center, prospective, observational study conducted at the University of Health Sciences Ankara Training and Research Hospital. The primary clinical challenge addressed is the intense postoperative pain following median sternotomy for Coronary Artery Bypass Grafting (CABG), which requires multimodal analgesia. The use of ultrasound-guided interfascial plane blocks has gained popularity due to their ease of application and lower complication rates compared to traditional methods.

Rationale for Comparison:

The Erector Spinae Plane Block (ESPB) has proven efficacy in thoracic and abdominal procedures. The Serratus Posterior Superior Intercostal Plane Block (SPSIPB) is being investigated as a potential alternative, targeting a broader area to manage pain in cardiac surgery. The study aims to provide clinical evidence regarding which of these two specific regional techniques offers superior postoperative pain control in this patient population.

Procedure Detail (Specific to Observation):

The selection of the block type (ESPB or SPSIPB) for the patient is determined intraoperatively by the experienced anesthesiologist based on the quality of the ultrasound image (visibility of the transverse processes) to ensure the most anatomically suitable block is performed.

Anesthesia Protocol (Standardized):

All enrolled patients (ASA II-III) will receive the same general anesthesia protocol (Thiopental, Fentanyl, Rocuronium for induction; Sevoflurane for maintenance). The regional block will be administered by a single experienced anesthesiologist under the supervision of the responsible investigator, using a bilateral injection of 30 mL of 0.25% Bupivacaine for both techniques. Postoperative analgesia will be managed using a standardized Intravenous Patient-Controlled Analgesia (PCA) device, set at a 3mg/ml concentration, with a 24mg bolus dose and a 20-minute lockout interval.

Inclusion criteria

• Patients scheduled for elective Coronary Artery Bypass Grafting (CABG) via median sternotomy.
• Age between 18 and 80 years.
• Classification of American Society of Anesthesiologists (ASA) Physical Status Class II or III.
• Patients who provide written and verbal informed consent to participate in the study.

Exclusion criteria

• Patients who do not provide consent.
• Age older than 80 years or ASA Physical Status Class > III.
• Patients who do not understand the Numerical Rating Scale (NRS) or have communication difficulties.
• Patients with a known history of coagulation disorders or bleeding disorders.
• Patients with skin infection at the site of peripheral nerve block application.
• Patients with Morbid Obesity (Body Mass Index BMI>35 kg/m2).
• Patients with chronic pain, opioid or substance dependence, or who use chronic analgesics.
• Patients with known allergy to local anesthetics.
• Patients with liver or kidney function disorders.
• Patients with a history of previous median sternotomy operation.
• Patients undergoing emergency surgery.