The intertransverse process block (ITPB) is an alternatives technique of regional anesthesia for thoracic surgery. However, the precise technique of ITPB remains developing. This study aims to evaluate the efficacy of ITPB injections which are single and triple injection in adult-patients undergoing video-assisted thoracoscopic surgery. The investigators hypothesize that cutaneous sensory block and perioperative pain outcomes including pain intensity and opioids consumption in patients who received triple injections of ITPB are better than that of single injection.

Objectives: evaluate the efficacy of single and triple injections of ultrasound-guided ITPB in adult patients undergoing video-assisted thoracoscopic surgery for pulmonary resection Setting: Single center tertiary teaching hospital Participants: adult-patients who undergoing scheduled video-assisted thoracoscopic surgery for pulmonary resection.

Intervention: The patient will divide to 2 groups of intervention: single injection of ITPB (S-group) and triple injection of ITPB (T-group). The ITPB will be perform after routine general anesthesia. The primary outcomes is to compare the distribution of cutaneous block after single and triple injections of ultrasound-guided ITPB in adult patients undergoing video-assisted thoracoscopic surgery for pulmonary resection. The distribution of cutaneous block will be evaluate at PACU.

Inclusion Criteria:

1. Patients aged 20-70 years old
2. Undergoing scheduled the first time for each side of video-assisted thoracoscopic surgery (VATS) for pulmonary resection
3. American Society of Anesthesia (ASA) physical status I-III
4. Patients have ability to communicate and understand the study and accept to participate in study
5. Body weight >40 kg

Exclusion Criteria:

1. Patients who allergic to bupivacaine, lidocaine, NSAIDS, paracetamol, and dexamethasone
2. Patients who have following underlying disease: renal impairment (diagnosed of end-stage renal disease (ESRD) or chronic kidney disease (CKD) which estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 square meters) , hepatic impairment (diagnosed of cirrhosis or evidence of abnormal liver function test which are increased liver enzymes or bilirubin level), coagulopathy (diagnosed of disease associated with abnormal coagulation, currently use any anticoagulants or evidence of prolong prothrombin time (PT) or partial thromboplastin time (PTT)), thrombocytopenia (platelet count less than 150,000/microliter), platelet disfunction from any causes such as current use antiplatelet or uremia (BUN level > 60 mg/dL) , morbid obesity (BMI >40 kg/m2), pre-existing neurological deficits, chronic pain (diagnosed of chronic pain disease or current use regular analgesic drugs), or any drug addiction • Withdrawal criteria: a participant will be withdrawn from the study in case of

1. Procedural failure: the operator cannot place the needle tip in the intertransverse tissue according to the technical difficulty or abnormal anatomy after 15 minutes of performing the block (from the beginning of needle insertion to the injection of local anesthetic) 2. Anesthetic related events including cardiac arrest, difficult intubation 3. Surgical related events including massive bleeding, major organ injury, converted operation to open thoracotomy and reoperation within admission 4. Participant related reasons including patient's willing to withdraw from the study or failure to adhere adequately to protocol requirements such as premature discharge. However, the withdrawn participant will be continued follow up of clinical outcome.

The IPD will not be shared