Median Effective Volume of Bupivacaine for Serratus Posterior Superior Intercostal Plane Block in Video-Assisted Thoracoscopic Surgery Using the Dixon Method

What this Trial Is About

Researchers are evaluating the minimum effective volume of bupivacaine required for the serratus posterior superior intercostal plane (SPSIP) block in patients undergoing video-assisted thoracoscopic surgery (VATS). This ultrasound-guided regional anesthesia technique is used to provide pain relief after thoracic surgery. The study aims to identify the volume that controls pain effectively in 50% of patients to improve pain management while reducing drug exposure. Participants will receive an ultrasound-guided SPSIP block with 0.5% bupivacaine before surgery. The volume of local anesthetic is adjusted in 2 mL steps using the Dixon up-and-down method based on block success or failure in preceding patients. Success is defined by sensory loss in at least two dermatomes and low fentanyl use after anesthesia. The study continues until nine reversal points are reached to calculate the median effective dose (ED50). During the study, a blinded assessor evaluates block success 20-30 minutes after the block. Researchers will measure primary outcomes within 30 minutes, including the median effective volume of bupivacaine. Secondary outcomes include pain scores, opioid use, adverse effects, recovery quality, and pulmonary function up to 24 hours after surgery. Participants provide informed consent and are monitored throughout the study process.

Minimum Effective Volume of Bupivacaine for Serratus Posterior Superior Intercostal Plane Block in Video-Assisted Thoracoscopic Surgery