Prospective, randomized comparison of epidural versus parenteral opioid analgesia in thoracic trauma

Objective To evaluate systemic versus epidural opioid administration for an algesia in patients sustaining thoracic trauma. Summary Background Data The authors have previously shown that epidural ana lgesia significantly reduces the pain associated with significant chest wal l injury. Recent. studies report that epidural analgesia is associated with a lower catecholamine and cytokine response in patients undergoing electiv e thoracotomy compared with patient-controlled analgesia (PCA). This study compares the effect of epidural analgesia and PCA on pain relief, pulmonary function, cathechol release, and immune response in patients sustaining si gnificant thoracic trauma. Methods Patients (ages 18 to 60 years) sustaining thoracic injury were pros pectively randomized to receive epidural analgesia or PCA during an 18-mont h period. Levels of serum interleukin (IL)-1 beta, IL-2, IL-6, IL-8, and tu mor necrosis factor-alpha (TNF-alpha) were measured every 12 hours for 3 da ys by enzyme-linked immunosorbent assay. Urinary catecholamine levels were measured every 24 hours. Independent observers assessed pulmonary function using standard techniques and analgesia using a verbal rating score; Results Twenty-four patients of the 34 enrolled completed the study. Age, i njury severity score, thoracic abbreviated injury score, and length of hosp ital stay did not differ between the two groups. There was no significant d ifference in plasma levels of IL-1 beta, IL-2, IL-6, or TNF-alpha or urinar y catecholamines between the two groups at any time point. Epidural analges ia was associated with significantly reduced plasma levels of IL-8 at days 2 and 3, verbal rating score of pain on days 1 and 3, and maximal inspirato ry force and tidal volume on day 3 versus PCA. Conclusions Epidural analgesia significantly reduced pain with chestwall ex cursion compared with PCA. The route of analgesia did not affect the catech olamine response. However, serum levels of IL-8, a proinflammatory chemoatt ractant that has been implicated in acute lung injury, were significantly r educed in patients receiving epidural analgesia on days 2 and 3. This may h ave important clinical implications because lower levels of IL-8 may reduce infectious or inflammatory complications in the trauma patient. Also, tida l volume and maximal inspiratory force were improved with epidural analgesi a by day 3; These results demonstrate that epidural analgesia is superior t o PCA in providing analgesia, improving pulmonary function, and modifying t he immune response in patients with severe chest injury.