Preemptive low-dose epidural ketamine for preventing chronic postthoracotomy pain: a prospective, double-blinded,...

Chronic postthoracotomy pain is the most common long-term complication that occurs after a thoracotomy with a reported incidence of up to 80%. Although thoracic epidural analgesia is a widely used method for managing acute postthoracotomy pain, its effects seems questionable. The objective of this prospective, double-blinded, randomized, controlled trial was to assess the effect of preemptive low-dose epidural ketamine in addition to preemptive thoracic epidural analgesia on the incidence of chronic postthoracotomy pain.

We analyzed 133 patients who were randomized to preemptive thoracic epidural analgesia either with or without ketamine (Group K: 0.12% levobupivacaine, 2 μg/mL of fentanyl, 0.2 mg/mL ketamine, total volume of 500 mL vs. Group KF: 0.12% levobupivacaine, 2 μg/mL of fentanyl, total volume of 500 mL). Pain at the thoracotomy scar site during rest and movement (coughing) was assessed at 2 weeks and 3 months after surgery using a visual analog scale. The incidence of allodynia and numbness was also evaluated.

There was no difference in the incidence of chronic postthoracotomy pain at 3 months between the 2 groups (67.7% in group K vs. 75% in group KF). The incidences of allodynia or numbness were not different between the 2 groups.

The addition of preemptive low-dose epidural ketamine (1.2 mg/h) to preemptive thoracic epidural analgesia did not have any beneficial effects in preventing chronic postthoracotomy pain.