B-003PREVENTIVE APPLICATION OF LIDOCAINE PATCH IN ADJUNCTION TO INTRAVENOUS MORPHINE ANALGESIA FOR MANAGEMENT OF POST-THORACOTOMY PAIN: RESULTS OF A RANDOMIZED, DOUBLE BLIND, PLACEBO CONTROLLED STUDY

Abstract

Objectives: Lidocaine patch is usually used for management of chest-wall pain, thus we supposed that its application at site of thoracotomy before surgery would potentiate the effect of intravenous morphine analgesia and reduce the acute and subacute post-thoracotomy pain. Methods: This was a unicentre, double-blind, placebo controlled, prospective study. Patients were randomly assigned to receive Lidocaine 5% patch (Lidocaine Group) or a placebo (Placebo Group) before thoracotomy in 1:1 ratio. The patch was placed at the site of thoracotomy three days before the operation for 12 hours per day. All patients received intravenous morphine analgesia in the first 48 postoperative hours. Primary end-point was pain relief measured with the VAS scale at rest and after cough. Secondary endpoints were the recovery of FEV1 and FVC, the reduction of morphine consumption, and the rate of side effects. In addition, laser-evoked potentials (LEPs) were measured before and 1, 3, and 6 months after operation to quantify the neuropatic pain. Differences were assessed with the ANOVA test. Results: Ninety patients were randomized of whom 45 allocated to the Lidocaine Group and 45 to the Placebo Group. Baseline characteristics were comparable. Lidocaine compared to Placebo Group showed reduction of VAS scores at rest (P = 0.01) and after cough (P = 0.01); increase of FEV1 (P = 0.02) and FVC (P = 0.02); and reduction of total morphine consumption (P < 0.001). The lidocaine patch was not correlated to specific side effects. Regarding LEPs value, Placebo compared to Lidocaine group presented a reduction of N2 (P < 0.001) and P2 amplitude (P = 0.03) and increase of N2 (P = 0.02) and P2 (P = 0.03) latency, expressions of persistent pain. Conclusion: The preventive application of Lidocaine 5% patch is an easy, safe, and effective adjunct to intravenous morphine analgesia for controlling postthoractomy pain. The benefits are maintained 6 months after operation.