Comparison of lumbar epidural tramadol and lumbar epidural morphine for pain relief after thoracotomy: A repeated-dose study - Reply

Abstract

We read with interest and appreciate the comments made by Dr Singh and colleagues regarding our article “Comparison ofLumbar Epidural Tramadol and Lumbar Epidural Morphine for Pain Relief after Thoracotomy: A Repeated-Dose Study.” Bothlumbar and thoracic catheters can be used for postoperative thoracotomy pain management. Despite the theoretical advantage ofrequiring smaller amounts of drug to provide analgesia solely via thoracic dermatomes, the superiority of thoracic epidural analgesiaover lumbar epidural analgesia has been called into question. In the meta-analysis of 8 studies comparing thoracic versus lumbarepidural opioid administration, Ballantyne and associates1found no differences in pain scores, pulmonary function, and theincidence of side effects. As a result of limited evidence confirming the benefits of thoracic versus lumbar epidural analgesia, someauthors have expressed caution in routinely using thoracic epidural analgesia.2-4Furthermore, most anesthesiologists are morecomfortable placing lumbar epidural catheters because these catheters are placed below the conus medullaris, avoiding the risk ofinjuring the spinal cord if the dura is inadvertently punctured during thoracic epidural placement. Furthermore, thoracic epiduralcatheter placement can be technically more difficult because of the greater caudad angulation of the spinous processes.Immediately after awakening from anesthesia, all patients complained of pain, with a visual analog scale score higher than 40mm at rest, and received the first dose of study drug via epidural catheter. Therefore, we did not discuss analgesia for the patientswho scored less than 40 mm in this period. With our pain management protocol, no patient had consistently high pain scores duringthe 24-hour study period.