This study aimed to compare rhomboid intercostal plane block and serratus posterior superior intercostal plane block (SPSIPB) to determine the most suitable technique for maintaining postoperative analgesia in video-assisted thoracoscopic surgeries (VATS).

Patients were randomly allocated into two groups: RIB and SPSIPB. All patients received postoperative paracetamol and dexketoprofen, and intravenous tramadol hydrochloride was administered via patient-controlled analgesia. Postoperative static and dynamic NRS scores, total tramadol consumption, side effects, and the need for additional analgesia were monitored and recorded at regular intervals. Primary outcome was NRS scores and secondary outcome was total tramadol consumption.

Block Techniques

All blocks were performed following surgical closure, prior to extubation, with the patient in lateral decubitus and the skin prepared with 10% povidone-iodine.

RIB:Rhomboid intercostal plane block procedure is performed using a high-frequency linear ultrasound probe. First, the rhomboid and intercostal muscles are located in the area called the auscultation triangle, at the level of thoracic 4-5 o'clock. A needle, visible on ultrasound, is advanced between the rhomboid and intercostal muscles using an in-plane technique. After aspiration is performed to ensure no blood or air is present, a total of 30 ml of 0.25% bupivacaine will be injected between the two muscle planes. The rhomboid intercostal plane block creates sensory paresthesia (sensory numbness) in a dermatomal region between T3 and T9 o'clock.

SPSIPB: The USG probe was placed 2-3 cm medial to the scapular spine to visualize the trapezius, rhomboid major, and serratus posterior superior muscles. At the level of the 2nd-3rd ribs, a needle was advanced into the plane between the serratus posterior superior muscle and the rib. After confirming negative aspiration, 30 mL of 0.25% bupivacaine was injected.

All blocks were performed unilaterally, targeting the surgical hemithorax.

Postoperative Analgesia and Assessments

Twenty minutes before extubation, all patients received 1 g IV paracetamol and 50 mg IV dexketoprofen. In the recovery room, patient-controlled analgesia (PCA) with IV tramadol hydrochloride was initiated (4 mg/mL concentration, 10 mg bolus, 20-minute lockout, maximum 3 boluses/hour).

Postoperative NRS scores (static at rest and dynamic during movement or coughing) were recorded at 0, 1, 2, 6, 12, 18, and 24 hours. The first NRS assessment (0 hour) was performed when the patient achieved an Aldrete score of 9. If NRS ≥ 4, an additional 50 mg IV tramadol was administered. Additional analgesic consumption was recorded. Side effects such as nausea, vomiting, and pruritus were documented.

Inclusion Criteria:

• Forty adult patients scheduled for elective wedge resection or biopsy under VATS, classified as American Society of Anesthesiologists (ASA) physical status I-III, were enrolled after providing written informed consent.

Exclusion Criteria:

• ASA class IV or higher,
• morbid obesity (BMI > 40 kg/m²),
• body weight ≤ 50 kg,
• skin infection at the block site,
• refusal to participate,
• inability to cooperate during postoperative pain assessment,
• conversion to open surgery,
• preexisting pain,
• known allergy to any study medication,
• coagulopathy.