Trial design Despite video-assisted thoracic technology and procedure specific postoperative pain management (PROSPECT) have been promoted through recent years, thoracic surgery is still considered to be one of the most painful of surgical procedures. This study aims to optimize these conditions according to different perioperative analgesic modes recommended at present. This will be a single-blind randomized study to investigate the optimal analgesic effect of thoracic paravertebral block (TPB), erector spinae block (ESB), or sufentanil patient controlled intravenous analgesia (PCIA) for uniportal video-assisted thoracoscopic surgery (uVATS) and using minimally invasive drainage.

Methods One-hundred and two patients undergoing uVATS will be enrolled. Patients will be randomly assigned to PVB group (20mL 0.3% ropivacaine with dexamethasone), ESB group (20mL 0.3% ropivacaine with dexamethasone) or CON group. PCIA with sufentanil will be provided to all patients after surgery. Primary outcome will be total opioid consumption from the end of the surgery to the time of discharge. Secondary outcomes consist of postoperative pain score, postoperative chronic pain, both at rest and during coughing, sensations of touch and pain on the chest wall, non-opioid analgesic drug use, length of stay (LOS), ambulation time, total cost of hospitalization and long-term postoperative analgesia. Adverse reaction to analgesics and adverse event related to regional block will also be recorded.

Ethics and dissenmination This study is approved by the Ethics Committee of China-Japan Friendship Hospital (ID 2022-KY-127-1). The results will be published in peer-reviewed journals.

Key words: fast-track; Enhanced Recovery After Surgery; uniportal video-assisted thoracoscopic surgery; randomized controlled trial; thoracoscopic; ultrasonic guidance; paravertebral block; erector spinal block

This is a prospective, randomized controlled study. Patients who are scheduled for elective uniportal thoracoscopic surgery in our hospital will be enrolled. Patients will be randomly assigned to one of the three groups: ultrasound-guided paravertebral block, ultrasound-guided erector spinae block, or intravenous patient-controlled analgesia pump group. Different nerve block operation schemes will be used in different groups.

In any of the three groups, general anesthesia will be performed according to the standard, and multi-mode analgesic treatment will be appied as the combination of NSAIDs analgesics, opioid analgesics, and postoperative rescue analgesic treatment. Participants will be followed up at 1, 4, 12, 18 hours, on 1, 2, 3, 4, 7 days, and in 1, 2, 3, 4, 6 months after surgery. At each follow-up visit, rest and cough pain level will be recorded, and sense of touch and pain in the chest will be examined. Additional analgesic treatment will be given if necessary.

Comparisons of the postoperative analgesic use, cough and rest pain, ambulation time, length of hospital stay, and hospital costs will be made in the three groups.

Inclusion Criteria:

1. ≥18 years
2. ASA I-IIa
3. Early stage lung cancer or intrathoracic tissue biopsy, suitable for elective uVATSb
4. Informed consent obtained

Exclusion Criteria:

1. ASA≥III
2. History of intrathoracic or chest wall surgery
3. Chronic pain
4. Pre-operative analgesic medication use
5. NSAIDsc contraindications: aspirin asthma, allergic to NSAIDs, peptic ulcer, liver and kidney insufficiency, high risk of thrombotic events
6. Active autoimmune disease
7. Allergic to local anesthetics
8. Severe coagulation dysfunction, contraindicated for nerve block
9. Soft tissue infections of the chest wall

Security cameras are set up next to both the computer and the cabinet for data storage. The surveillance video will be available only to medical staff and the principal investigator. Access to data will be restricted to authorized personnel, including ethics committee directors, principal investigator and authorized personnel. Access to paper documents as well as electronic data must be registered, with the name of operator and detailed reasons recorded.

The results and conclusions of our research will be reported to all the participants, research team, and the public in peer-reviewed journal. The investigators will try to put forward the existing guidelines to further optimization of perioperative anesthesia and analgesia protocol for small-incision thoracic surgery and optimized drainage tube strategy.

Patients will be grouped by block randomization method (1:1:1) by a researcher who is unaware of the meaning of the group code. Patients will be stratified by ID numbers with a block of 6. Within each block, random sequences between 0 and 1 are generated. The group code (A, B or C) will be defined as the remainder of the serial number divided by three. The group code will be put in a light-proof envelope. Patients with the envelope will be transferred to the OR, unaware of the group assignment throughout the study. After induction, the anesthesiologist opens the light-proof envelope and get the group code. Group codes will be recorded in the CRF table with the cards destroyed. Only the principal investigator and the anesthesiologists know the intervention represented by the group code. The anesthesiologists will not involve in postoperative follow-ups or data collection. Neither doctors in charge of postoperative follow-ups nor the statisticians will know the specific interventions.