Effectiveness of High-Voltage, Long-Duration Pulsed Radiofrequency in the Treatment of Postherpetic Neuralgia in the Elderly: Protocol for a Randomized Clinical Trial.

Introduction: Pulsed Radiofrequency (PRF) is a minimally invasive, non-neurodestructive interventional therapy commonly used in pain management. However, the optimal PRF parameters have yet to be clearly defined, and the clinical efficacy of different PRF settings in elderly patients with postherpetic neuralgia (PHN) remains uncertain. Therefore, this study aims to determine whether high-voltage, long-duration PRF (HLPRF) can offer better pain relief, improve sleep quality, and reduce anxiety symptoms in elderly PHN patients, without increasing the risk of PRF-related adverse events. Methods: This investigator-initiated, single-center, randomized, two-arm clinical trial enrolls patients over 65 years of age with PHN who are scheduled for PRF surgery. A total of 88 eligible patients will be randomly assigned to either the standard PRF group or the HLPRF group. In the standard PRF group, the output voltage is set at 45 V with a pulse duration of 360 seconds. In the HLPRF group, the output voltage is set at 85 V and the pulse duration at 900 seconds. All other parameters and treatment protocols are consistent across both groups. Data for this trial were systematically collected at multiple time points, including at admission and at 4, 12, 26, and 52 weeks postoperatively. The primary outcome measure was the postoperative Numerical Rating Scale (NRS) score. Secondary outcomes included several key indicators: postoperative Pregabalin dosage, Pittsburgh Sleep Quality Index (PSQI), 12-Item Short Form Health Survey (SF-12), and Hospital Anxiety and Depression Scale (HADS). Adverse events occurring during the intraoperative period and throughout the postoperative follow-up will be meticulously documented as critical safety indicators. Subgroup analyses will be conducted post hoc to examine potential differences based on whether patients exhibit frailty, thereby providing nuanced insights into the treatment outcomes among different patient populations. Conclusion: The results of this study may provide evidence-based medical evidence for the use of HLPRF for the treatment of PHN and may help to assist clinicians in selecting different parameters PRF for the treatment of PHN for clinical practice. Trial Registration Number: ChiCTR2400086627.