Post-thoracotomy pain relief: Thoracic paravertebral block compared with systemic opioids

Abstract

BackgroundWe evaluated the safety and efficacy of thoracic paravertebral block as a method of pain relief after thoracotomy in comparison with systemic opioids.Study designRandomized controlled trial.MethodsWe 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.ResultsVisual 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 (P 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) (P 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.There was no significant difference between the two groups as regards to peak expiratory flow rate (PEFR) preoperatively, after 12 h or 24 h.There was a significant reduction in the incidence of side effects in the TPVB group compared to morphine group concerning vomiting and pruritus.no local anesthetic toxicity was reported.ConclusionWe 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.