Investigators will analyze the efficacy of continuous regional anesthesia through a catheter under erector spinae muscle in a prospective, randomized, double blind, placebo-controlled study. Investigators will include 50 adults, predicted for elective lung surgery with video-assisted thoracic surgery (VATS) technique. Patients will be randomly assigned to group A or B.

Investigators will insert a catheter under the erector spinae muscle (ESC) at the T4 level of the operated side under ultrasound guidance. All patients will receive an initial bolus of 20ml levobupivacaine 0,5% through the catheter. Group A will receive a continuous infusion 5ml/h of ropivacaine 0,2% and intermittent boluses of the same local anesthetic 15ml/4h through the ESC. Group B will receive a continuous infusion of 0,9% saline in the same doses. All patients will have a PCA pump with piritramide 1mg/ml to cover the pain. All patients will receive regular doses of paracetamol and metamizole as part of multimodal analgesia.

Investigators will compare pain, assessed with the VAS scale in resting and coughing and piritramide usage in both groups. Investigators will compare the incentive spirometry results at 24 and 48 hours postoperatively and observe for possible late complications.

Inclusion Criteria:

• Signed written informed consent
• ASA I-III
• Elective video-assisted thoracic surgery with 3 ports technique
• No contraindications for regional anesthesia

Exclusion Criteria:

• Allergy to local anesthetic
• Pregnancy, breastfeeding
• BMI>35
• Inflammation in the area of ES catheter insertion
• Inability to use the PCA pump

Anonymous IPD may be shared.

After the collection of data has finished.

Primary researcher consent.

Masking the infusion mixture by using the same shape of the drug/placebo bottle and wrapping it into non-transparent sheath.