{"title":"在神经电刺激中,从肌肉收缩的强度可以推断出与神经的距离吗?可能的参数和误差来源]。","authors":"P März","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Electrical nerve stimulation is a useful tool in regional anesthesia; it assists in locating the nerves. This investigation deals with electrical resistances at adhesive electrodes attached to the skin. The influence of external electrical resistance on the stimulating impulse is demonstrated. A new type of nerve stimulator is described; which integrates a measuring device that indicates the electrical impulse actually flowing in the patient. With this device, relationships between stimulating impulse, intensity of muscle contraction, and distance of the puncture cannula from the nerve can be assessed. MATERIALS AND METHODS. The electrical curve I = f (R) was determined using 3 different nerve stimulators (R = 1 - 15k omega). On each of five test persons, five adhesive electrodes were attached to the skin 10 cm apart. The resistance was assessed between these electrodes and a subcutaneously inserted puncture needle. The right and left brachial plexuses of the 5 subjects were punctured, using the axillary approach. A synchronized video camera simultaneously recorded the following values: (1) electrical impulse; (2) corresponding muscle contraction; and (3) the position of the puncture cannula. A scale ranging from 0-5 was applied to define the strength of the muscle contractions. RESULTS. The external resistance as measured under clinical conditions may limit the output impulse of nerve stimulators. In this case, the exerting impulse is lower than that indicated by the appliance. This error can only be identified using an impulse-measuring device. Nerve stimulators not equipped with a measuring device increase the risk of malpuncture, potentially resulting in nerve lesions. Skin resistance at adhesive electrodes varied from patient to patient within a range of 1.1 to 8.2 K omega. Preparing the skin appropriately (wiping with sandpaper) decreased the resistance by only 6% during the first 30 min. Within a distance of 50 cm to the puncture needle, the position of the adhesive electrode did not play a significant role. Axillary puncture of the brachial plexus resulted in the following values: (1) A stimulating impulse (cross-wave) of 1 mA and 1 ms exerted at a distance of 4 mm to the nerve induced a contraction of strength 3. (2) Reducing the impulse at this site by one-half (0.55 mA) resulted in just-visible contractions (strength 1). (3) Advancing the cannula at a stimulating impulse of 0.55 mA inside the neurovascular sheath again produced contractions of strength 3. (4) Performing the puncture with a blunt needle and tracing a distinct resistance, the impulse of 0.6 mA elicited contractions of strength 2. The needle tip was still outside the vascular nerve sheath. If this resistance was overcome and the needle tip lay inside the neurovascular sheath, the impulse could be reduced by one-half (0.32 mA) to produce contractions of strength 2.</p>","PeriodicalId":77604,"journal":{"name":"Regional-Anaesthesie","volume":"13 7","pages":"179-85"},"PeriodicalIF":1.9000,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"[In electric nerve stimulation can the distance from the nerves be inferred from the intensity of muscle contraction? Possible parameters and sources of error].\",\"authors\":\"P März\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Electrical nerve stimulation is a useful tool in regional anesthesia; it assists in locating the nerves. This investigation deals with electrical resistances at adhesive electrodes attached to the skin. The influence of external electrical resistance on the stimulating impulse is demonstrated. A new type of nerve stimulator is described; which integrates a measuring device that indicates the electrical impulse actually flowing in the patient. With this device, relationships between stimulating impulse, intensity of muscle contraction, and distance of the puncture cannula from the nerve can be assessed. MATERIALS AND METHODS. The electrical curve I = f (R) was determined using 3 different nerve stimulators (R = 1 - 15k omega). On each of five test persons, five adhesive electrodes were attached to the skin 10 cm apart. The resistance was assessed between these electrodes and a subcutaneously inserted puncture needle. The right and left brachial plexuses of the 5 subjects were punctured, using the axillary approach. A synchronized video camera simultaneously recorded the following values: (1) electrical impulse; (2) corresponding muscle contraction; and (3) the position of the puncture cannula. A scale ranging from 0-5 was applied to define the strength of the muscle contractions. RESULTS. The external resistance as measured under clinical conditions may limit the output impulse of nerve stimulators. In this case, the exerting impulse is lower than that indicated by the appliance. This error can only be identified using an impulse-measuring device. Nerve stimulators not equipped with a measuring device increase the risk of malpuncture, potentially resulting in nerve lesions. Skin resistance at adhesive electrodes varied from patient to patient within a range of 1.1 to 8.2 K omega. Preparing the skin appropriately (wiping with sandpaper) decreased the resistance by only 6% during the first 30 min. Within a distance of 50 cm to the puncture needle, the position of the adhesive electrode did not play a significant role. Axillary puncture of the brachial plexus resulted in the following values: (1) A stimulating impulse (cross-wave) of 1 mA and 1 ms exerted at a distance of 4 mm to the nerve induced a contraction of strength 3. (2) Reducing the impulse at this site by one-half (0.55 mA) resulted in just-visible contractions (strength 1). (3) Advancing the cannula at a stimulating impulse of 0.55 mA inside the neurovascular sheath again produced contractions of strength 3. (4) Performing the puncture with a blunt needle and tracing a distinct resistance, the impulse of 0.6 mA elicited contractions of strength 2. The needle tip was still outside the vascular nerve sheath. If this resistance was overcome and the needle tip lay inside the neurovascular sheath, the impulse could be reduced by one-half (0.32 mA) to produce contractions of strength 2.</p>\",\"PeriodicalId\":77604,\"journal\":{\"name\":\"Regional-Anaesthesie\",\"volume\":\"13 7\",\"pages\":\"179-85\"},\"PeriodicalIF\":1.9000,\"publicationDate\":\"1990-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Regional-Anaesthesie\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"POLITICAL SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Regional-Anaesthesie","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"POLITICAL SCIENCE","Score":null,"Total":0}
引用次数: 0
摘要
神经电刺激是区域麻醉的有效手段;它有助于定位神经。这项研究涉及附着在皮肤上的粘接电极上的电阻。论证了外部电阻对刺激脉冲的影响。介绍了一种新型的神经刺激器;它集成了一个测量装置,可以显示病人体内实际流动的电脉冲。使用该装置,可以评估刺激冲动、肌肉收缩强度和穿刺套管与神经的距离之间的关系。材料和方法。使用3种不同的神经刺激器(R = 1 - 15k ω)测定电曲线I = f (R)。在5名被试者身上,每个人的皮肤上分别贴上5个相距10厘米的粘性电极。在这些电极和皮下插入的穿刺针之间评估电阻。采用腋窝入路穿刺5例患者的左右臂丛。一台同步摄像机同时记录下以下数值:(1)电脉冲;(2)相应的肌肉收缩;(3)穿刺套管的位置。用0-5的刻度来定义肌肉收缩的强度。结果。在临床条件下测量的外部阻力可能会限制神经刺激器的输出脉冲。在这种情况下,施加的冲量小于器具所指示的冲量。这种误差只能通过脉冲测量装置来识别。没有配备测量装置的神经刺激器增加了穿刺不当的风险,可能导致神经损伤。粘附电极上的皮肤电阻在1.1至8.2 K ω的范围内因人而异。在最初的30分钟内,适当地准备皮肤(用砂纸擦拭)仅降低了6%的阻力。在距离穿刺针50厘米的距离内,粘附电极的位置没有起显着作用。腋窝穿刺臂丛的结果如下:(1)在距离神经4mm处施加1ma和1ms的刺激脉冲(交叉波),引起强度3的收缩。(2)将该部位的脉冲减少一半(0.55 mA),导致刚刚可见的收缩(强度为1)。(3)在神经血管鞘内以0.55 mA的刺激脉冲推进套管,再次产生强度为3的收缩。(4)用钝针穿刺,追踪到明显的阻力,0.6 mA的脉冲引起强度为2的收缩。针尖仍在血管神经鞘外。如果克服了这种阻力,针尖位于神经血管鞘内,则脉冲可以减少一半(0.32 mA),从而产生强度为2的收缩。
[In electric nerve stimulation can the distance from the nerves be inferred from the intensity of muscle contraction? Possible parameters and sources of error].
Electrical nerve stimulation is a useful tool in regional anesthesia; it assists in locating the nerves. This investigation deals with electrical resistances at adhesive electrodes attached to the skin. The influence of external electrical resistance on the stimulating impulse is demonstrated. A new type of nerve stimulator is described; which integrates a measuring device that indicates the electrical impulse actually flowing in the patient. With this device, relationships between stimulating impulse, intensity of muscle contraction, and distance of the puncture cannula from the nerve can be assessed. MATERIALS AND METHODS. The electrical curve I = f (R) was determined using 3 different nerve stimulators (R = 1 - 15k omega). On each of five test persons, five adhesive electrodes were attached to the skin 10 cm apart. The resistance was assessed between these electrodes and a subcutaneously inserted puncture needle. The right and left brachial plexuses of the 5 subjects were punctured, using the axillary approach. A synchronized video camera simultaneously recorded the following values: (1) electrical impulse; (2) corresponding muscle contraction; and (3) the position of the puncture cannula. A scale ranging from 0-5 was applied to define the strength of the muscle contractions. RESULTS. The external resistance as measured under clinical conditions may limit the output impulse of nerve stimulators. In this case, the exerting impulse is lower than that indicated by the appliance. This error can only be identified using an impulse-measuring device. Nerve stimulators not equipped with a measuring device increase the risk of malpuncture, potentially resulting in nerve lesions. Skin resistance at adhesive electrodes varied from patient to patient within a range of 1.1 to 8.2 K omega. Preparing the skin appropriately (wiping with sandpaper) decreased the resistance by only 6% during the first 30 min. Within a distance of 50 cm to the puncture needle, the position of the adhesive electrode did not play a significant role. Axillary puncture of the brachial plexus resulted in the following values: (1) A stimulating impulse (cross-wave) of 1 mA and 1 ms exerted at a distance of 4 mm to the nerve induced a contraction of strength 3. (2) Reducing the impulse at this site by one-half (0.55 mA) resulted in just-visible contractions (strength 1). (3) Advancing the cannula at a stimulating impulse of 0.55 mA inside the neurovascular sheath again produced contractions of strength 3. (4) Performing the puncture with a blunt needle and tracing a distinct resistance, the impulse of 0.6 mA elicited contractions of strength 2. The needle tip was still outside the vascular nerve sheath. If this resistance was overcome and the needle tip lay inside the neurovascular sheath, the impulse could be reduced by one-half (0.32 mA) to produce contractions of strength 2.