[Clinical evaluation of in-plane ultrasound-guided thoracic paravertebral block using laterally intercostal approach]

To evaluate the feasibility and success rate of in-plane ultrasound-guided paravertebral block using laterally intercostal approach.

In the study, 27 patients undergoing elective thoracic surgery were selected to do paravertebral block preoperatively. The fifth intercostal space was scanned by ultrasound probe which was placed along the long axis of the rib and 8 cm lateral to the midline of the spine. The needle was advanced in increments aiming at the space between the internal and innermost intercostal muscles. Once the space between the muscles was achieved, 20 mL of 0.5% (mass fraction) ropivacaine was injected and a catheter was inserted. Whether the tip of catheter was in right place was evaluated by ultrasound image. The block dermatomes of cold sensation were recorded 10, 20 and 30 min after the bolus drug was given. Then 0.2% ropivacaine was infused with 6 mL/h via the catheter by an analgesia pump postoperatively. The block dermatomes of cold sensation and pain score were recorded 1, 6, 24 and 48 h postoperatively.

The first attempt success rate of catheteration was 81.48% (22/27); the tips of catheter were proved in right places after the second or third attempt in 5 patients. The median numbers of the block dermatomes 10, 20 and 30 min after the bolus drug was given were 2, 3, 4; the median numbers of block dermatomes were 5, 5, 5, 4, and of pain score were 1, 1, 2, 2 at 1, 6, 24, 48 h postoperatively; no case of bilateral block, pneumothorax or vessel puncture occurred.

Thoracic paravertebral block using laterally intercostal approach is feasible, which has high success rate of block and low rate of complications.