Percutaneus radiofrequency ablation (RFA) of liver tumors causes acute pain during the periooperative setting. In order to facilitate tumor access, patient should collaborate with a surgeon during the procedurę, therefore should be conscious.

This study aims to assess the impact of a single shot thoracic paravertebral block (TPVB) on a patient's haemodynamic stability, patient's and operator's comfort and satisfaction during the operation and analgesia in the post-operative period.

High temperatures used during the percutaneus radiofrequency ablation (PRFA) of liver tumors can cause acute pain in the perioperative setting. In order to facilitate tumor exposure and access, patient should collaborate with a surgeon during the procedurę, therefore should be conscious. It is mandatory to provide an adequate acute postoperative pain control for our patients.

This prospective randomized, single center study was approved by the Bioethics Committee at the University of Warmia and Mazury in Olsztyn, (Poland) under the resolution No. 46/2017.

Inclusion Criteria:

• patients with primary liver tumor (HCC)
• patient scheduled for an elective surgery
• tumor diameter) <5 cm two tumors <3cm
• Age >18 years
• Physical State 1,2 or 3 of the American Society of Anesthesiology (ASA)

Exclusion Criteria:

• ASA IV and V
• Thrombocytopenia (<40x10 ^ 9 / L)
• Severe cirrhosis (Child-Pugh C classification)
• History of psychiatric/cognitive disease
• Patients who do not give informed consent
• Patients with contraindications or history of hypersensitivity to local anaesthesia drugs
• History of chronic pain, chronic opioid use (> 3 months)

De-identified study participants data for all primary and secondary outcome measures

Data will be available within 12 months of study completion

Data will be made available for researchers who provide a methodologically sound proposal. Proposals should be directed to m.braczkowska@gmail.com . Data access requests will be reviewed by an External Independent Review Panel. To gain access, data requestors will need to sign a data access agreement.

Participants were randomly assigned into 2 groups (computerized randomization program).

group PVB - patients under paravertebral block anesthesia, group BB - patients under local anesthesia, without paravertebral block.