Prediction of Individual Analgesic Response to Intravenous Lidocaine in Painful Diabetic Peripheral Neuropathy

Supplemental Digital Content is available in the text. Objectives: Intravenous lidocaine can alleviate painful diabetic peripheral neuropathy (DPN) in some patients. Whether quantitative sensory testing (QST) can identify treatment responders has not been prospectively tested. Materials and Methods: This was a prospective, randomized, double-blind, crossover, placebo-controlled trial comparing intravenous lidocaine to normal saline (placebo) for painful DPN. Thirty-four participants with painful DPN were enrolled and administered intravenous lidocaine (5 mg/kg ideal body weight) or placebo as a 40-minute infusion, after a battery of QST parameters were tested on the dorsal foot, with a 3-week washout period between infusions. Results: Thirty-one participants completed both study sessions and were included in the final analysis. Lidocaine resulted in a 51% pain reduction 60 to 120 minutes after infusion initiation, as assessed on a 0 to 10 numerical rating scale, while placebo resulted in a 33.5% pain reduction (difference=17.6%, 95% confidence interval [CI], 1.9%-33.3%, P=0.03). Neither mechanical pain threshold, heat pain threshold, or any of the other measured QST parameters predicted the response to treatment. Lidocaine administration reduced mean Neuropathic Pain Symptom Inventory paresthesia/dysesthesia scores when compared with placebo by 1.29 points (95% CI, −2.03 to −0.55, P=0.001), and paroxysmal pain scores by 0.84 points (95% CI, −1.62 to −0.56, P=0.04), without significant changes in burning, pressing or evoked pain subscores. Discussion: While some participants reported therapeutic benefit from lidocaine administration, QST measures alone were not predictive of response to treatment. Further studies, powered to test more complex phenotypic interactions, are required to identify reliable predictors of response to pharmacotherapy in patients with DPN.

文中有补充数字内容。目的：静脉注射利多卡因可缓解部分糖尿病周围神经病变（DPN）患者的疼痛。定量感觉测试（QST）能否识别治疗应答者尚未经过前瞻性测试。材料与方法：这是一项前瞻性、随机、双盲、交叉、安慰剂对照试验，比较静脉注射利多卡因与生理盐水（安慰剂）对疼痛性DPN的疗效。招募了34名疼痛性DPN患者，在对足背进行一系列QST参数测试后，分别给予静脉注射利多卡因（理想体重5mg/kg）或安慰剂，输注时间为40分钟，两次输注之间有3周的洗脱期。结果：31名参与者完成了两项研究疗程并纳入最终分析。根据0 - 10数字评分量表评估，利多卡因在输注开始后60 - 120分钟使疼痛减轻51%，而安慰剂使疼痛减轻33.5%（差异 = 17.6%，95%置信区间[CI]，1.9% - 33.3%，P = 0.03）。机械痛阈、热痛阈或任何其他测量的QST参数均不能预测治疗反应。与安慰剂相比，利多卡因给药使神经性疼痛症状量表的感觉异常/痛觉异常平均评分降低1.29分（95% CI，-2.03至 - 0.55，P = 0.001），阵发性疼痛评分降低0.84分（95% CI，-1.62至 - 0.56，P = 0.04），烧灼感、压痛或诱发性疼痛子评分无显著变化。讨论：虽然一些参与者报告利多卡因给药有治疗益处，但仅QST测量不能预测治疗反应。需要进一步开展有足够效能以测试更复杂表型相互作用的研究，以确定DPN患者对药物治疗反应的可靠预测因子。