Epinephrine 4 μg/ml added to a low-dose mixture of ropivacaine and fentanyl for lumbar epidural analgesia after total knee arthroplasty

BACKGROUND: Epinephrine 2 mu g/mL added to a local anesthetic-opioid mixture has been found to improve postoperative continuous epidural analgesia at the thoracic (TEA) but not at lumbar (LEA) level. Therefore, we studied whether a higher dose of epinephrine could improve LEA. METHODS: Patients received LEA comprising of ropivacaine 1.8 mg/mL and fentanyl 3 mu g/mL either without (group RF, n = 32) or with epinephrine 4 mu g/mL (group RFE, n = 31) for 2 days after total knee arthroplasty. Rescue pain medication consisted of epidural top-ups (study mixture) and parenteral oxycodone. RESULTS: Total amounts of epidurally administered drugs were significantly higher in group RFE. Otherwise, the groups did not differ significantly regarding pain relief and side effects. CONCLUSIONS: As part of the multimodal pain treatment used, the epidural adjuvant epinephrine 4 mu g/mL (12-32 mu g/h) did not improve LEA after total knee arthroplasty.