RESPONSE TO IV LIDOCAINE PREDICT FAVORABLE RESPONSE TO ORAL MEXILETIE

幻肢痛和残肢痛是截肢后常见的后遗症。最近的研究估计，50%-75%的截肢者在截肢后早期会出现幻觉疼痛。持续性幻觉疼痛很难治疗，而且往往会随着时间的推移而恶化。残肢疼痛不太常见，通常会随着时间的推移而减轻。我们采用双盲随机方案，比较静脉注射利多卡因和吗啡与安慰剂对肢体截肢后幻觉和残肢疼痛的疗效。在机构调查审查委员会批准后，6名患者(2名女性和4名男性)在1997年1月12日至1998年11月30日期间入选。排除标准包括18岁或90岁，心脏传导缺陷，6个月内心肌梗死，严重的肺部、肝脏或血液系统疾病，以及癫痫、痴呆或脑病病史。采用双盲法，先静脉注射利多卡因(5 mg/kg)、吗啡(0.25 mg/kg)或苯海拉明(25 Mg)，持续30分钟。从给药前30分钟开始，每隔5分钟记录一次幻影和/或残肢疼痛，以及由黄铜探头在残肢敏感区域上诱发的疼痛，并在输液结束后30分钟继续记录。将Drun诱导的疼痛评分变化与输液前的基线疼痛评分进行比较。在5例受试者中，利多卡因降低幻觉疼痛评分(范围4.50%~68.40%)，吗啡降低4例(范围1.46%~39%)。其中一名患者对注射吗啡没有反应。在接受测试的5名患者中，只有2名患者对苯海拉明安慰剂输注有反应(范围=2%-4.77%)。6名受试者中，利多卡因(范围23.50%~100%)和吗啡(范围13.76%~67.63%)均可降低残端疼痛评分。在接受测试的6名患者中，只有3名报告使用苯海拉明安慰剂缓解残端疼痛(范围=0.49%-10.75%)。

Phantom Limb pain and stump pain are common post-amputation sequela. Most recent studies estimate 50-75% of amputees suffer from phantom pain early after amputation. Persistent phantom pain is difficult to treat and often worsens over time. Stump pain is less common and often decreases with time. we determined the efficacy of intravenous lidocaine and morphine infusions as compared to placebo on phantom and stump pain after amputation of extremities using a double-blind randomized protocol. Six patients (2 F and 4 M) were enrolled between 12/01/97 and 11/30/98 following approval by the institutional investigational review board. Exclusion criteria included age <18 or >90, cardiac conduction defects, myocardial infarction within 6 months, severe pulmonary, hepatic, or hematologic disease, and history of seizures, dementia, or encephalopathy. In a double blind fashion, an intravenous bolus followed by an infusion of lidocaine (5mg/kg), or morphine (0.25mg/kg), or diphenhydramine (25mg) were administered over 30 minutes. Phantom and/ or stump pain, and pain evoked by a brass probe over the sensitive region of the stump were recorded at 5 minute intervals starting 30 minutes prior to bolus dose and continued 30 minutes after the end of infusion. The drun-induced change in pain scores were compared to preinfusion baseline pain scores. Phantom pain scores were decreased by lidocaine (range = 4.50% - 68.40%) in all 5 patients tested, and by morphine (range = 1.46% - 39%) in 4 out of 5 patients tested. One of the patients did not respond to morphine infusion. Only 2 out of 5 patients tested responded to diphenhydramine placebo infusion (range = 2%-4.77%). Stump pain scores were decreased by lidocaine (range = 23.50% - 100%), and by morphine (range = 13.76% - 67.63%) in all 6 patients tested. Only 3 out of 6 patients tested reported stump pain relief (ranges = 0.49% - 10.75%) to diphenhydramine placebo infusion.