Paravertebral block: an improved method of pain control in percutaneous transhepatic biliary drainage.

BACKGROUND AND PURPOSE: Percutaneous transhepatic biliary drainage remains a painful procedure in many cases despite the routine use of large amounts of intravenous sedation. We present a feasibility study of thoracic paravertebral blocks in an effort to reduce pain during and following the procedure and reduce requirements for intravenous sedation.

METHODS: Ten consecutive patients undergoing biliary drainage procedures received fluoroscopically guided paravertebral blocks and then had supplemental intravenous sedation as required to maintain patient comfort. Levels T8-T9 and T9-T10 on the right were targeted with 10-20 ml of 0.5% bupivacaine. Sedation requirements and pain levels were recorded.

RESULTS: Ten biliary drainage procedures in 8 patients were performed for malignancy in 8 cases and for stones in 2. The mean midazolam use was 1.13 mg i.v., and the mean fentanyl requirement was 60.0 microg i.v. in the block patients. Two episodes of hypotension, which responded promptly to volume replacement, may have been related to the block. No serious complications were encountered. The mean pain score when traversing the chest wall, liver capsule, and upon entering the bile ducts was 0.1 on a scale of 0 to 10, with 1 patient reporting a pain level of 1 and 9 reporting 0. The mean peak pain score, encountered when manipulating at the common bile duct level or when addressing stones there, was 5.4 and ranged from 0 to 10.

CONCLUSIONS: Thoracic paravertebral block with intravenous sedation supplementation appears to be a feasible method of pain control during biliary interventions.