Postoperative Analgesic Comparison of SPSI Block and SAP Block in Video-Assisted Thoracoscopic Surgery (VATS)

In our study, we primarily aimed to compare the postoperative analgesic effectiveness of the Serratus Posterior Superior Intercostal Plane Block and the Serratus Anterior Plane Block, both routinely applied in patients undergoing Video-Assisted Thoracoscopic Surgery (VATS)

In Video-Assisted Thoracoscopic Surgery (VATS), the thoracic cavity is visualized through a small incision in the chest wall. VATS allows for procedures such as lobectomy, bullectomy, and wedge resection (1). Compared to thoracotomy, VATS offers lower costs, better pulmonary function, less pain, and earlier postoperative mobilization (2). The success of postoperative rehabilitation in thoracic surgery patients can be improved with minimally invasive procedures and effective pain control.

The multimodal analgesic approach, which involves the combined use of analgesic drugs with different mechanisms (NSAIDs, paracetamol, opioids, etc.) along with regional/local techniques, aims to achieve additive and synergistic effects. This approach reduces the need for high doses of a single analgesic, minimizes side effects, and provides more effective pain control (3)(4).

In our hospital's operating room, opioids, NSAIDs, paracetamol, intravenous patient-controlled analgesia (PCA) devices, and regional techniques such as thoracic paravertebral block, serratus anterior plane block (SAPB), serratus posterior superior intercostal plane block (SPSIPB), and erector spinae plane (ESP) block are routinely applied for postoperative pain management in VATS patients.

The primary objective of our study is to compare the effects of Serratus Posterior Superior Intercostal Plane Block (SPSIPB) and Serratus Anterior Plane Block (SAPB), both routinely used in our thoracic anesthesia practice, on postoperative pain scores and analgesic needs in VATS patients.

The SAPB, which is an essential component of multimodal analgesia in thoracic surgery, offers safe and precise analgesic effects with low complication rates. The block covers most VATS incisions and chest tube sites, providing better postoperative analgesia and potentially improving lung function (5).

Similarly, SPSIPB, another thoracic wall fascial plane block, has been shown to be effective in managing both acute and chronic pain (6). It is reported to provide good analgesia in the thoracic region after VATS (7).

The study will include patients aged 18-80 years scheduled for VATS at Uludağ University Medical Faculty Hospital. Patients with ASA I, II, and III classifications will be included.

Patients will be randomized into two groups:

Group 1: SPSIPB (n=45) Group 2: SAPB (n=45) Both blocks will be applied after standard anesthesia induction, intubation, surgical positioning, and before surgical incision.

During the intraoperative period, if heart rate or mean arterial pressure (MAP) increases by more than 20% from baseline measurements, IV fentanyl (1 µg/kg) will be administered as needed. Prior to the surgical incision, all patients will receive IV paracetamol (10 mg/kg), tenoxicam (20 mg), and metoclopramide (10 mg) as part of routine practice.

Fifteen minutes before awakening, a patient-controlled analgesia (PCA) device will be connected to each patient. The PCA device will be prepared with 1 mg/ml morphine solution, with a bolus dose of 2 ml and a lockout interval of 15 minutes. In patients with an NRS score of ≥4, IV tramadol (100 mg/2 ml) will be administered as a rescue analgesic. The pain score at the time of rescue analgesia, the time of the first PCA request, and the NRS score at that time will be recorded.

Eligibility Criteria:
Inclusion Criteria:

* Patients aged 18 to 80 years undergoing Video-Assisted Thoracoscopic Surgery (VATS)
* Scheduled at Uludağ University Faculty of Medicine Hospital Operating Room
* Classified as ASA I, II, or III according to the American Society of Anesthesiologists (ASA) criteria

Exclusion Criteria:

* Allergy to local anesthetics or contraindications to bupivacaine
* Known or suspected coagulopathy
* Infection at the injection site
* History of thoracic surgery
* Severe neurological or psychiatric disorders
* Severe cardiovascular disease
* Liver failure
* Renal failure (glomerular filtration rate \< 15 ml/min/1.73 m²)
* Chronic opioid use