Effects of Preemptive Epidural Analgesia on Post-thoracotomy Pain

Objective: The purpose of this study was to determine whether preemptive thoracic epidural analgesia (TEA) initiated before surgical incision would reduce the severity of acute post-thoracotomy pain and the incidence of chronic post-thoracotomy pain. Method: Meta-analysis of randomized controlled trials (RCTs) Search Strategy: MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE were searched from 1966 to December 2004 for prospective RCTs published in all languages using the following MeSH terms: post-thoracotomy pain, epidural analgesia, chronic pain, and preemptive analgesia. Selection Criteria: All RCTs that compared thoracic epidural analgesia initiated before surgical incision (preemptive group) versus thoracic epidural analgesia initiated after completion of surgery (control group) in adult patients undergoing unilateral thoracotomy. Measurements and Main Results: Three authors reviewed all citations and simultaneously extracted data on sample size, patient characteristics, surgical and analgesic interventions, methods of pain assessment, and pain scores at 24 hours, 48 hours, and 6 months postoperatively. Six studies were included with a total of 458 patients. Pooled analyses indicated that preemptive TEA was associated with a statistically significant reduction in the severity of acute pain on coughing at 24 and 48 hours (weighted mean difference −1.17 [95% confidence interval (CI) −1.50 to −0.83] and −1.08 [95% CI −1.17 to −0.99]), respectively. Acute pain was a good predictor of chronic pain. However, there was no statistically significant difference in the overall incidence of chronic pain at 6 months between the preemptive TEA group (39.6%) and the control group (48.6%). Conclusion: Preemptive TEA appeared to reduce the severity of acute pain but had no effect on the incidence of chronic pain.