A single paravertebral injection via a needle vs. a catheter for the spreading to multiple intercostal levels: a...

Thoracic paravertebral block (TPVB) provides a unilateral nerve block at multiple intercostal levels allowing injection of a local anesthetic into paravertebral space (PVS) via a needle or catheter. However, the most effective injection method remains unclear. This study compared the real-time spread of ropivacaine between two paravertebral injection methods using thoracoscopy.

Thirty-four patients scheduled for thoracoscopic surgery were randomly allocated into the Needle or Catheter groups, and performed transverse in-plane ultrasound-guided TPVB. The Needle group received 20 ml of 0.5% ropivacaine via a needle placed into the lateral edge of PVS; the Catheter group received the same dose of ropivacaine via a catheter inserted 5 cm into PVS. The primary outcome was the spreading pattern of ropivacaine in each group. The secondary outcome was intraoperative vasopressor requirement after paravertebral injection.

In the Needle group, all cases showed ropivacaine spread to multiple intercostal levels, mainly across the ribs. Contrastingly, the Catheter group showed variable spreading patterns; multiple intercostal levels (n = 10) [across the ribs (n = 4), anterolateral aspect of the vertebral bodies (n = 6)] or unobservable spreading (no change; n = 7) (P = 0.007). Vasopressors were required in two and ten cases in the Needle and Catheter groups, respectively (P = 0.010).

Paravertebral injection via a needle typically resulted in spreading to multiple intercostal levels, especially across the ribs on the peripheral side of injection site, whereas injection via a catheter resulted in variable spreading patterns. Therefore, injections via needles are more stable.