Increased sensitivity to thermal pain and reduced subcutaneous lidocaine efficacy in redheads
Increased sensitivity to thermal pain and reduced subcutaneous lidocaine efficacy in redheads
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DOI：
10.1097/00000542-200503000-00006
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发表时间：
2005-03-01
期刊：
影响因子：
8.8
通讯作者：
Sessler, DI
中科院分区：
文献类型：
--
作者：
Liem, EB;Joiner, TV;Sessler, DI
背景红头发的麻醉需求被夸大了，这表明红头发的人可能对疼痛特别敏感。方法：作者通过用Neurometer CPT/C（Neurotron，Inc.，巴尔的摩，MD）。他们用TSA-II神经感觉分析仪（Medoc Ltd.，Minneapolis，MN）。志愿者在基线时使用两种器械进行测试，并在暴露于4%利多卡因脂质体1小时后和皮下注射1%利多卡因后使用神经测定仪进行测试。数据以中位数（四分位数范围）表示。结果：在2,000、250和5 Hz频率下，红发和黑发女性的电流感知、疼痛感知和疼痛耐受阈值相似。相比之下，红头发的人对冷痛的感知更敏感（22.6 [15.1-26.1] vs. 12.6 [0-20] ℃; P = 0.004），冷痛耐受性（6.0 [0-9.7] vs. 0.0 [0.0-2.0] ℃; P = 0.001）和热痛（46.3 [45.7-47-5] vs. 47.7 [46.6-48.7] ℃; P = 0.009）。皮下注射利多卡因对红发人的效果明显较差（例如，在2,000 Hz刺激下，红头发患者的疼痛耐受阈值为11.0 [8.5-16-5]，而其他患者的疼痛耐受阈值> 20.0（14.5-> 20）mA; P = 0.005）。结果表明，红头发的人对热痛更敏感，对皮下利多卡因的镇痛作用有抵抗力。因此，黑皮质素-1受体的突变或其后果调节疼痛敏感性。
Background Anesthetic requirement in redheads is exaggerated, suggesting that redheads may be especially sensitive to pain. Therefore, the authors tested the hypotheses that women with natural red hair are more sensitive to pain and that redheads are resistant to topical and subcutaneous lidocaine.Methods: The authors evaluated pain sensitivity in red-haired (n = 30) or dark-haired (n = 30) women by determining the electrical current perception threshold, pain perception, and maximum pain tolerance with a Neurometer CPT/C (Neurotron, Inc., Baltimore, MD). They evaluated the analogous warm and cold temperature thresholds with the TSA-II Neurosensory Analyzer (Medoc Ltd., Minneapolis, MN). Volunteers were tested with both devices at baseline and with the Neurometer after 1-h exposure to 4% liposomal lidocaine and after subcutaneous injection of 1% lidocaine. Data are presented as medians (inter-quartile ranges).Results: Current perception, pain perception, and pain tolerance thresholds were similar in the red-haired and dark-haired women at 2,000, 250, and 5 Hz. In contrast, redheads were more sensitive to cold pain perception (22.6 [15.1-26.1] vs. 12.6 [0-20]degreesC; P = 0.004), cold pain tolerance (6.0 [0-9.7] vs. 0.0 [0.0-2.0]degreesC; P = 0.001), and heat pain (46.3 [45.7-47-5] vs. 47.7 [46.6-48.7]degreesC; P = 0.009). Subcutaneous lidocaine was significantly less effective in redheads (e.g., pain tolerance threshold at 2,000-Hz stimulation in redheads was 11.0 [8.5-16-5] vs. > 20.0 (14.5 to > 20) mA in others; P = 0.005).Conclusion: Red hair is the phenotype for mutations of the melanocortin-1 receptor. Results indicate that redheads are more sensitive to thermal pain and are resistant to the analgesic effects of subcutaneous lidocaine. Mutations of the melanocortin-1 receptor, or a consequence thereof, thus modulate pain sensitivity.