Double-blind comparison of intrapleural saline and 0.25% bupivacaine for ipsilateral shoulder pain after thoracotomy in patients receiving thoracic epidural analgesia

Background. The aim of this prospective double-blind randomized placebo-controlled study was to investigate the effect of intrapleural bupivacaine on ipsilateral post-thoracotomy shoulder pain in patients receiving thoracic epidural analgesia. Methods. Of the 68 patients recruited to the study, 41(60%) developed ipsilateral shoulder pain within 2 h of surgery. These patients were randomly assigned to receive either 40 ml of intrapleural bupivacaine 0.25% with epinephrine 1:200 000 or 40 ml of intrapleural saline. The study solution was injected into the tube of a basal drain that had been clamped distal to the site of administration. Shoulder pain at rest and on coughing was assessed using a visual analogue scale (VAS) and an observer verbal rating score (OVRS) immediately before and 30 min, 1 h, 2 h, 3 h and 4 h after intrapleural bupivacaine/saline. The total volume of epidural solution administered was recorded. Results. Thirty-nine patients completed the study and were included in the analysis. There were no significant differences in baseline characteristics between the two groups. There were no significant differences between groups for VAS or OVRS pain scores at rest or with cough at any of the six assessment times. The total volumes of epidural solution administered to the bupivacaine and saline groups were 56 ml and 48 ml, respectively. This difference was not significant. Conclusion. Intrapleural administration of 40 ml of bupivacaine 0.25% does not provide effective pain relief for ipsilateral post-thoracotomy shoulder pain.