Epinephrine markedly improves thoracic epidural analgesia produced by a small-dose infusion of ropivacaine, fentanyl, and epinephrine after major thoracic or abdominal surgery: a randomized, double-blinded crossover study with and without epinephrine.

Abstract

We have shown that epinephrine markedly improves the analgesic effect of a thoracic epidural infusion of bupivacaine and fentanyl. Ropivacaine has an intrinsic vasoconstrictive effect, and epinephrine may therefore not have the same pharmacokinetic interaction in a ropivacaine-fentanyl infusion; but a possible spinal cord alpha(2)-agonist effect of epinephrine would give the same positive pharmacodynamic interaction with ropivacaine and fentanyl during epidural analgesia. In a prospective, randomized, crossover study, a thoracic epidural infusion of ropivacaine 1 mg/mL and fentanyl 2 microg/mL with or without epinephrine 2 microg/mL was given to 12 patients in a double-blinded manner after major thoracic or upper abdominal surgery. Main outcome measures were pain intensity at rest and when coughing, evaluated on a visual analog scale. Extent of sensory blockade was evaluated by determining dermatomal hypoesthesia to cold. Pain increased (P < 0.001) and hypoesthetic dermatomal segments decreased (P < 0.001) when epinephrine was omitted from the triple epidural infusion. After 3 h without epinephrine, pain intensity when coughing was unacceptable despite rescue analgesia. After restarting the triple epidural mixture with epinephrine, pain was again reduced to mild pain when coughing, and the sensory blockade was restored. The mixture with epinephrine caused less nausea and facilitated mobilization. We conclude that epinephrine improves the pain relief and reduces the side effects of a thoracic epidural infusion of ropivacaine and fentanyl after major thoracic or upper abdominal surgery. Epidural epinephrine markedly improves the pain relief and sensory blockade of a small-dose thoracic epidural infusion of ropivacaine and fentanyl. Nausea was reduced, and mobilization of the patients was facilitated.