Background
We evaluated the safety and efficacy of thoracic paravertebral block as a method of pain relief after thoracotomy in comparison with systemic opioids.
Study design
Randomized controlled trial.
Methods
We scheduled 40 patients divided into two groups to receive either 20 ml bupivacaine (0.5%) incremental injections for intra and postoperative analgesia via a catheter inserted in the thoracic paravertebral space. The other 20 patients received systemic morphine for postoperative analgesia. We recorded postoperative Visual Analog Scale pain score, total morphine consumption, time to first analgesic request, changes in pulmonary functions and side effects.
Results
Visual analogue scale (VAS) at rest was lower in the paravertebral group at all measurement points except at 16, 20 and 24 h postoperatively. Pain on coughing showed significant difference ( value < 0.05) at 8 and 16 h but not at 24 h. Post-operative consumption of morphine was 36 (22–42) mg in the control group versus 9 (2–22) mg in the paravertebral block group (PVB) ( value = 0.003). Total bupivacaine dose used in the PVB group in the first 24 h was 300–420 mg. For time to first analgesic request it was significantly longer in the morphine group than the paravertebral block group. VAS at first analgesic request was not statistically different between the two groups.
Conclusion
We conclude that thoracic PVB provides effective post thoracotomy analgesia supported by lower VAS pain scores at rest and on coughing compared to intravenous morphine with significant less incidence of side effects.