Traditionally, video-assisted thoracic surgery is performed under general anesthesia with double-lumen endotracheal tube. However, the complications associated with this large tube as well as inhalation anesthetics are frequently reported. Therefore, currently there is a trend toward non-intubated anesthesia methods for video-assisted thoracic surgery, which includes thoracic epidural block, peripheral nerve block, local anesthesia, local combined with peripheral nerve block, etc. Thoracic epidural block demands a high technique, but still risks catastrophic neurological complications in case of accidental dural puncture. Local anesthesia, perhaps more straightforward, however may need supplemental analgesia during incision, which will inevitably interrupt surgery and negatively affect the patients. This study aims to apply ultrasound guidance during local anesthetic injection for local anesthesia-based video assisted thoracic surgery, which helps inject the local anesthetic into the key intercostal nerve plane to provide more specific and precise blockade, thus avoiding the chance of blind injection. At the same time, ultrasound guidance has the potential to reduce the risk of systemic toxicity, prolong the duration of analgesia postoperatively, and facilitates postoperative recovery.

Inclusion Criteria:

• Adults younger than 80 years old and weighing between 50-90 kg are scheduled for one-port video assisted thoracic surgery .

Exclusion Criteria:

• Anticipated difficult airway
• Obvious coagulation abnormality
• Psychiatric patients or drug addiction
• Emergency operation or patients with a full stomach
• Difficulty in language expression
• Allergic to local anesthetic, morphine, or NSAID
• BMI > 35
• Pregnancy
• Respiratory insufficiency
• Severe pleural adhesion
• Need for pleurodesis
• Refuse patient-controlled analgesia
• Patients with a pacemaker
• Severe liver dysfunction (serum albumin<25g/l or Child-Pugh score≧10)
• Severe kidney dysfunction (creatinine clearance<30ml/min)
• Inflammatory bowel disease
• Congestive heart failure (NYHA II-IV)
• Confirmed ischemic heart disease, peripheral arterial disease and/or cerebral vascular disease
• Patients with a high intra-ocular pressure (e.g. glaucoma)
• Neurological symptoms over the ipsilateral upper part of the body