Evaluation of the Analgesic Efficacy of Serratus Posterior Superior Intercostal Plane (SPSIP) Block in Shoulder Arthroscopies: A Randomized Controlled Prospective Multicenter Study

Patients in the block group will be placed in a lateral position with the operated shoulder on top before awakening from surgery. After ensuring aseptic conditions (the block site will be wiped three times with 10% povidone-iodine), the linear ultrasound probe will be covered in a sterile manner. While performing the block, the Hitachi brand linear ultrasound probe will be placed parallel to the scapular spine on the surgical side and will be slid medially. After imaging the 2nd and 3rd ribs on the medial side of the scapular spine, the block needle will be advanced under ultrasound guidance onto the 3rd rib. After contacting the rib with the needle, it will be retracted by 1mm, and the block site will be confirmed by injecting sterile 0.9% NaCl. Subsequently, patients will be administered 30ml of 0.25% bupivacaine in a controlled manner.

Before awakening, both the block group and the non-block group will be administered 1g of paracetamol and 1mg/kg of tramadol intravenously. In the postoperative period, these patients will be provided with multimodal analgesia, including intravenous patient-controlled analgesia (PCA) with 4mg/ml Tramadol HCl in 100ml NaCl. There will be no basal infusion, with bolus doses of 20mg and a lockout period of 20 minutes, and a total dose limitation of 200mg over 4 hours. Patients will be visited at 0, 1, 6, 12, and 24 hours, and they will be asked to draw their visual analog scale (VAS) score on a paper scale. The amount of opioid used in the PCA and the need for rescue analgesia (Arveles 50mg intravenously) will be assessed. Patients will routinely receive 4x1g paracetamol in the postoperative period.