The Effects of Lidocaine Patches on Post-Radiofrequency Ablation Pain in Patients With Hepatocellular Carcinoma.

[BACKGROUND AND AIM] Radiofrequency ablation (RFA) is a standard treatment for patients with early-stage hepatocellular carcinoma (HCC). However, analgesics are often insufficient in mitigating post-RFA pain. The lidocaine patch is being investigated as an alternative for acute pain relief, though it has not yet been used for post-RFA pain. This study aims to evaluate the effect of lidocaine patches on post-RFA pain for patients with HCC.

[METHODS] Patients undergoing RFA treatment were randomly assigned to an intervention group, receiving lidocaine patches (LP group), or a control group, receiving placebo patches (PP group). The primary endpoint was the Visual Analog Scale (VAS) pain score. The secondary endpoint was rescue analgesic use, quantified as the equivalent cumulative dose of residual morphine. Both were assessed concurrently every 4 h on the first day post-RFA.

[RESULTS] A total of 86 patients in the LP group and 68 patients in the PP group completed the study. Pain scores did not differ between the two groups at any time point. However, the equivalent cumulative dose of residual morphine was lower in the LP group compared to the PP group, with statistically significant differences at time points T4-T6 (p = 0.032, p = 0.018, and p = 0.032, respectively). After adjusting for confounding factors, multiple linear regression analysis yielded similar results.

[CONCLUSIONS] VAS pain scores, the primary endpoint, were not significantly different between the two groups. However, the objective equivalent cumulative dose of residual morphine was significantly reduced, implying that the lidocaine patch lowered residual systemic opioid exposure. We conclude that the lidocaine patch may be useful to reduce opioid use post-RFA.

[TRIAL REGISTRATION] ClinicalTrials.gov identifier: NCT05732181.