This study aims to study the analgesic and respiratory effects of the erector spinae plane block for patients undergoing video-assisted thoracic surgery (VATS) or robotic assisted thoracic surgery (RATS).

A total of 120 subjects will be randomized into three groups (30 per group). Arm A: IV PCIA Arm B: IV PCIA + ultrasound guided Erector spinae block (ESPB, Single shot of 30ml of 0.5% solution of Naropin [Ropivacaine]) Arm C: IV PCIA + multilevel intra-thoracic intercostal nerve block (ICB, Single shot of 30ml of 0.5% solution of Naropin [Ropivacaine]) PCIA pumps for all study cohorts will be programmed according to our institution's standard protocol (Dipidolor [Piritramide] bolus: 2mg, interval: 7 min, max 4h dose: 30mg). The erector spinae block will be placed preoperatively, the intercostal block will be placed at the beginning of the procedure. All patients will receive standard postoperative care. The patients will be blinded for the study arm.

The primary endpoint of this study is postoperative pain and will be recorded by using the numerical rating scale (NRS) pain score. Pain scores will be measured by the investigator at rest and during coughing. Opioid consumption will be monitored and registered for.

Inclusion Criteria:

• Male and female patients
• age between 18 to 100 years old
• ASA 1-3
• scheduled for VATS
• informed consent explained and signed

Exclusion Criteria:

• Patients < 18 years old, > 100 years old
• ASA physical status > 3
• previous cardiac surgery or ipsilateral thoracic surgery
• neuropsychiatric diseases
• allergy to analgesics or local anesthetics or other medications used in the study
• abuse of opioids or sedatives
• contraindication to receive regional anesthesia (e.g. coagulation defect)
• patients who could not understand the VAS pain-scoring system
• patient refusal to follow participation
• expected post operative mechanical ventilation
• intolerance or allergy to any prescribed medication