A comparison of a single-stimulation lateral infraclavicular plexus block with a triple-stimulation axillary block

BACKGROUND AND OBJECTIVES: A single-stimulation infraclavicular brachial plexus block (ICB) is safe and easy to perform, although underused. This technique was compared with a triple-stimulation axillary block (AxB). METHODS: One hundred patients scheduled for hand and forearm surgery were randomly allocated to 2 groups. ICB was performed with the needle inserted above the coracoid process in the upper lateral angle of the infraclavicular fossa and directed vertically until nerve stimulation elicited a distal motor response (median, radial, or ulnar). A single 40-mL bolus of ropivacaine 0.75% was injected. In the AxB group, 3 stimulations were performed to identify median or ulnar, radial, and musculocutaneous nerves, followed by an infiltration near the medial brachial and antebrachial cutaneous nerves. The same 40 mL of ropivacaine 0.75% was injected. Sensory and motor blocks were assessed at 5-minute intervals over 30 minutes. RESULTS: The time to block performance was shorter in the ICB than in the AxB group (2.5 +/- 1.9 minutes v 6.0 +/- 2.8 minutes, P <.001). The success rate (complete block in median, radial, ulnar, musculocutaneous, and medial antebrachial cutaneous nerves) was comparable in the 2 groups (90% v 88% in groups ICB and AxB, respectively). Block extension was comparable, except for a higher rate of block completion in the axillary nerve distribution in group ICB and in the medial brachial cutaneous nerve in group AxB. The onset of each nerve block was comparable except for a faster onset for the musculocutaneous nerve in group AxB (8 +/- 3 v 10 +/- 5 minutes). CONCLUSION: A single shot ICB is equally effective as a triple-nerve stimulation AxB.     

A comparison of stimulation patterns in axillary block: part 2

BACKGROUND AND OBJECTIVES: Radial plus musculocutaneous nerve stimulation may have a predominant role in the success of an axillary block, producing more extensive anesthesia of the upper limb than median plus musculocutaneous nerve stimulation. However, no comparison has been made with ulnar plus musculocutaneous nerve stimulation. We compared the extent of both sensory and motor block after ulnar plus musculocutaneous nerve stimulation or radial plus musculocutaneous nerve stimulation. METHODS: Sixty patients were randomly assigned to receive an axillary block using either radial plus musculocutaneous or ulnar plus musculocutaneous nerve stimulation with 40 mL plain 1.5% mepivacaine. Patients were assessed for sensory block by the pinprick method at 5 and 20 minutes. RESULTS: No statistically significant differences were found in the rates of anesthesia at 20 minutes in the cutaneous nerve distributions of the upper limb between radial plus musculocutaneous and ulnar plus musculocutaneous nerve stimulation except for the following nerves: radial (90% and 63.3%, respectively), medial cutaneous of the forearm (83.3% and 100%, respectively), and medial cutaneous of the arm (73.3% and 93.3%, respectively). Global sensory score (minimum: 0; maximum: 12 points) at 20 minutes was significantly higher after radial plus musculocutaneous than after ulnar plus musculocutaneous nerve stimulation: 12 (11-13) and 11 (10-12), respectively. The rates of median nerve blockade were 50% and 53%, respectively. CONCLUSIONS: Radial plus musculocutaneous nerve stimulation produced more extensive anesthesia of the upper limb than did ulnar plus musculocutaneous nerve stimulation. However, there is not an optimal combination of 2 responses in axillary brachial plexus block.     

Block of the brachial plexus branches by the humeral route. A prospective study in 503 ambulatory patients. Proposal of a nerve-blocking sequence

BACKGROUND: Brachial plexus is usually approached by the supraclavicular or axillary route. A technique for selective blockade of the branches of the plexus at the humeral canal using electrolocation has recently been proposed. The aim of the present study was to assess the feasibility of this technique in the ambulatory patient and to determine the optimal sequence of nerve-blocking. METHODS: The nerves originating from the brachial plexus were located in the humeral canal, at the junction of the proximal and the middle third of the arm, with a stimulator and blocked using either lidocaine or a mixture of lidocaine and bupivacaine, depending on the anticipated duration of surgery. The minimal stimulating intensity eliciting an adequate response, type of local anaesthetic and injected volume, and time of onset of surgical anaesthesia were collected. RESULTS: The study included 503 consecutive ambulatory patients due to undergo surgery of the elbow, wrist or hand in one year. Suitable anaesthesia was obtained with the humeral blockade in 82.1% of cases. In the remaining 17.9%, an additional block at the elbow was required, mainly for ulnar and median nerves. The onset times of sensory blocks were the longest for the median nerve, similar for the radial and ulnar nerves, shorter for the musculocutaneous nerve and the shortest for the medial brachial and antebrachial cutaneous nerves. The difference was more significant with the lidocaine-bupivacaine mixture, than with lidocaine alone (P<0.001 vs P<0.05, respectively). The onset times of motor blocks were the longest for the median nerve (P<0.05) and the shortest for the musculocutaneous nerve (P<0.001). Neither nervous nor vascular complications occurred. CONCLUSION: This study shows that the nerve block at the humeral canal is an efficient and safe technique. Considering the onset times of nerve blocks, the following sequence for blockade can be recommended: median, ulnar, radial, musculocutaneous, medial (brachial and antebrachial) cutaneous nerves. The selective blockade of the main nerves of the upper limb at the humeral canal can be recommended for surgery of the forearm and the hand in the ambulatory patient.     

Injuries of the terminal branches of the infraclavicular brachial plexus: patterns of injury, management and outcome

We reviewed 101 patients with injuries of the terminal branches of the infraclavicular brachial plexus sustained between 1997 and 2009. Four patterns of injury were identified: 1) anterior glenohumeral dislocation (n = 55), in which the axillary and ulnar nerves were most commonly injured, but the axillary nerve was ruptured in only two patients (3.6%); 2) axillary nerve injury, with or without injury to other nerves, in the absence of dislocation of the shoulder (n = 20): these had a similar pattern of nerve involvement to those with a known dislocation, but the axillary nerve was ruptured in 14 patients (70%); 3) displaced proximal humeral fracture (n = 15), in which nerve injury resulted from medial displacement of the humeral shaft: the fracture was surgically reduced in 13 patients; and 4) hyperextension of the arm (n = 11): these were characterised by disruption of the musculocutaneous nerve. There was variable involvement of the median and radial nerves with the ulnar nerve being least affected. Surgical intervention is not needed in most cases of infraclavicular injury associated with dislocation of the shoulder. Early exploration of the nerves should be considered in patients with an axillary nerve palsy without dislocation of the shoulder and for musculocutaneous nerve palsy with median and/or radial nerve palsy. Urgent operation is needed in cases of nerve injury resulting from fracture of the humeral neck to relieve pressure on nerves.     

Skin temperature after interscalene brachial plexus blockade

BACKGROUND AND OBJECTIVES: In neuraxial anesthesia, increase of skin temperature is an early sign of successful block. Yet, during peripheral nerve block of the lower extremity, increase in skin temperature is a highly sensitive, but late sign of a successful block. We hypothesized that after interscalene brachial plexus block, a rise in skin temperature follows impairment of sensation during successful nerve block and occurs only distally, as observed in the lower extremity. METHODS: In the present study, we prospectively evaluated the changes in skin temperature after interscalene brachial plexus blockade in 45 patients scheduled for elective shoulder surgery. We assessed pinprick and cold sensation as well as skin temperature at sites of the skin innervated by the median, ulnar, radial, axillary and musculocutaneous nerve. RESULTS: At the skin areas innervated by the axillary and musculocutaneous nerve, skin temperature did not increase after successful block. At the distal sites, innervated by the median, ulnar, and radial nerve, skin temperature increased significantly (1.9-2.1 degrees C within 30 min) after successful block while it did not after failed nerve block or on the contralateral side. In these areas attenuation of skin sensation preceded a measurable rise in skin temperature (> or =1 degrees C) in 56.3% of nerve blocks, occurred at the same time in 35.2%, and in 8.5% the temperature rise occurred first. CONCLUSIONS: Assessment of skin temperature cannot predict the success of an interscalene brachial plexus block of the axillary and musculocutaneous nerve. Distally, the increase of skin temperature has a high sensitivity and specificity but occurs later than the loss of sensory and motor functions. Therefore, the measurement of skin temperature during interscalene blockade is of limited clinical value.     

Axillary plexus block using a peripheral nerve stimulator: single or multiple injections

This prospective, randomized, double-blind study was undertaken to evaluate the success rates of axillary brachial plexus block performed with the help of a peripheral nerve stimulator when either one, two or four of the major nerves of the brachial plexus were located. Seventy-five patients undergoing upper limb surgery were randomly allocated to one of the following five groups according to the nerve and number of nerves to be located; G-1: musculo-cutaneous, radial, median and ulnar nerves; G-2: musculo-cutaneous plus one of the other three nerves; G-3: radial nerve; G-4: median nerve; G-5: ulnar nerve. The sensory block was evaluated before surgery and cutaneous anaesthesia was considered to be present when the needles of a Wartenberg Pinwheel were no longer felt in all the dermatomes of the nerves implicated in the surgical site. Otherwise, the block was considered to need completion before surgery. Only one out of the 15 patients in G-1 and G-2 needed completion of their block before surgery whereas seven out of 15 for G-3 and eight out of 15 for G-4 and G-5 needed completion of their block (P less than 0.01). We conclude that when performing an axillary block with the help of a peripheral nerve stimulator, stimulation of the musculo-cutaneous nerve and one other nerve or stimulation of all four major nerves of the brachial plexus gives a higher success rate than stimulation of only one nerve, whether the stimulated nerve is the median, radial or ulnar.     

Ultrasonographic findings of the axillary part of the brachial plexus

In this prospective study we sought to determine anatomic variations of the main brachial plexus nerves in the axilla and upper arm via high-resolution ultrasonography (US) examination. Positions of nerves were studied via US in three sectional levels of the upper arm in 69 healthy volunteers (31 men and 38 women, median age 28 yr). Analysis was done by subdividing the US picture into eight pie-chart sectors and matching sectors for the position of the ulnar, radial, and median nerves. Shortly after the nerves pass the pectoralis minor muscle, they begin to diverge. At the middle level 9%-13%, and at the distal level, 30%-81% of the nerves are not seen together with the artery in the US picture. At the usual level of axillary block approach, we found the ulnar nerve in the posterior medial position in 59% of the volunteers. The other two nerves had two peaks in distribution: the radial nerve in posterior lateral (38%) and anterior lateral (20%) position, and the median nerve in anterior medial (30%) and posterior medial (26%) position. Applying light pressure distally can displace nerves to the side, especially when they are positioned anterior to the axillary artery. We conclude that an axillary block should be attempted as proximal as possible to the axilla. IMPLICATIONS: This prospective ultrasonography study demonstrates significant anatomic variations of the main brachial plexus nerves in the axilla and upper arm, which may increase the difficulty in identifying neural structures. Applying light pressure on the plexus can move nerves to the side, especially when they are positioned anterior to the axillary artery.     

Variant location of the musculocutaneous nerve during axillary nerve block

We present the case of a 56-year-old man who underwent axillary nerve block for a wrist arthroscopy procedure, with real-time ultrasound and peripheral nerve stimulator guidance. The ulnar nerve and radial nerve were located medial and posterior to the brachial artery, respectively. A large complex structure was noted in the position typically occupied by the median nerve. Contact of this structure with the stimulating needle produced strong biceps contraction, and slight adjustment of the needle resulted in forearm pronation. After injection of 10 mL of local anesthetic near this structure, it appeared to consist of two separate components on ultrasound. We believe that these components represented the median and musculocutaneous nerves lying together, lateral to the artery. Radial, median, ulnar, and musculocutaneous nerve block ensued, and wrist arthroscopy was carried out uneventfully. Knowledge of this anatomical variation may improve anesthesiologists' ability to provide effective axillary block.     

Applied anatomy for upper limb nerve blocks

The brachial plexus derives from C5, C6, C7, C8 and T1 nerves. It is made up of five roots, between the scalene muscles, three trunks (upper, middle and lower) lying in the posterior triangle, each of which divide into anterior and posterior divisions behind the clavicle to form lateral, medial and posterior cords in the upper axilla. The plexus gives rise to the definitive motor and cutaneous nerve supply to the upper limb. The plexus can be blocked by local anaesthetic infiltration at its root/trunk level in the fascial sheath compartment between the scalenes, or as it crosses the first rib. Block can also be performed around the axillary artery. Peripherally, the nerves may be blocked at the elbow, wrist or finger level.     

Applied anatomy for upper limb nerve blocks

The brachial plexus derives from C5, C6, C7, C8 and T1 nerves. It is made up of five roots, between the scalene muscles, three trunks (upper, middle and lower) lying in the posterior triangle, each of which divide into anterior and posterior divisions behind the clavicle to form lateral, medial and posterior cords in the upper axilla. The plexus gives rise to the definitive motor and cutaneous nerve supply to the upper limb. The plexus can be blocked by local anaesthetic infiltration at its root/trunk level in the fascial sheath compartment between the scalenes, or as it crosses the first rib. Block can also be performed around the axillary artery. Peripherally, the nerves may be blocked at the elbow, wrist or finger level.     

Anatomy of nerve entrapment sites in the upper quarter.

The purpose of this article is to review the anatomical features of the most common nerve entrapment sites of the brachial plexus and major peripheral nerves of the upper limb. In this account, the term "entrapment" is considered to be caused by compression, tension, or friction, or any combination of these factors. The anatomy, including important relationships of the brachial plexus, is reviewed and the points of potential entrapment of the plexus are described. Entrapment of the suprascapular and long thoracic nerves is also included. Particular attention is paid to the five major peripheral nerves that result from the brachial plexus and supply the peripheral aspect of the upper limb, i.e., the median, ulnar, musculocutaneous, radial, and axillary nerves. In each case, the nerve's course is described and the anatomical details of the entrapment points described. Where possible, the sites of entrapment are illustrated in cadaveric photographs.     

Nerve transfer for treatment of brachial plexus injury：comparison study between the transfer of partial median and ulnar nerves and that of phrenic and spinal accessary nerves

Objective:To compare the effect of using partial median and ulnar nerves for treatment of C5-6 orC5-7 avulsion of the brachial plexus with that of using phrenic and spinal accessary nerves.Methods:The patients were divided into 2groups randomly according to different surgical procedures.Twelve cases were involved in the first group.The phrenic nerve was transferred to the musculocutaneous nerve or through a sural nerve graft,and the spinal accessary nerve was to the suprascapular nerve.Eleven cases were classified into the second group.A part of the fascicles of median nerve was transferred to be coapted with the motor fascicle of musculocutaneous nerve and a part of fascicles of ulnar nerve was transferred to the axillary nerve.The cases were followed up from 1to 3years and the clinical outcome was compared between the two groups.     

Effect of a lateral infraclavicular brachial plexus block on the axillary and suprascapular nerves as determined by electromyography – a cohort study

We aimed to examine to what extent a lateral infraclavicular brachial plexus block affected the axillary and the suprascapular nerve. We included patients undergoing hand surgery anaesthetised with a lateral infraclavicular brachial plexus block. Our primary outcome was the relative change in surface electromyography during maximum voluntary isometric contraction of the medial deltoid muscle (axillary nerve) and the infraspinatus muscle (suprascapular nerve) from baseline to 30 min after the block procedure. A reduction in electromyography of > 50% defined a successful block. The impact of the block on the shoulder nerves was compared with the surgical target nerves of the arm and hand (musculocutaneous, radial, median and ulnar nerves). Twenty patients were included. The medians of the relative changes in the surface electromyography were significantly reduced (both p < 0.001) with 92% for the deltoid muscle and 30% for the infraspinatus muscle, respectively. In total, 18 out of 20 patients had reductions > 50% for the deltoid muscle, which was significantly different from the infraspinatus muscle, where the proportion was 5 out of 20 (p < 0.001). The medians of the relative reductions in electromyography for the arm and hand muscles were 90–96%, similar to the effect on the deltoid muscle. Our results suggest that a lateral infraclavicular block provides block of the axillary nerve comparable to the block of the surgical target nerves. The suprascapular nerve is blocked to a lesser degree. Combining a lateral infraclavicular brachial plexus block with a selective suprascapular block for shoulder surgery warrants further studies.     

改良喙突入路臂丛神经阻滞的效果观察

目的 观察改良喙突人路臂丛神经阻滞的可行性.方法 60例ASA Ⅰ或Ⅱ级上肢手术患者随机均分为喙突法组(A组)和腋路法组(B组),A组在喙突尖向内下2 cm处绝缘针垂直于皮肤进入,B组取腋动脉上方搏动最强处进针.将神经刺激仪设置为电流1 mA、频率2 Hz.当电流减小到0.3 mA时仍可见到正中、尺、桡神经任一神经支配区肌肉颤搐时,固定刺激针,回吸无血后注入0.5%罗哌卡因 1%利多卡因混合液30 ml.比较两组的人针深度、止血带痛发生率、感觉及运动阻滞的成功率及时间.结果 A组人针深度明显深于B组(P＜0.05).A组止血带痛发生率明显短于B组(P＜0.05).A组中正中、桡、肌皮、腋、臂内侧皮神经感觉完全阻滞的成功率明显高于B组(P＜0.05),桡、肌皮、腋神经感觉达到完全阻滞的时间也明显短于B组(P＜0.01).A组运动完全阻滞的成功率明显高于B组(P＜0.05),达到最大运动阻滞的时间也明显短于B组(P＜0.01).结论 改良喙突人路法臂丛操作简便,阻滞成功率高,阻滞效果好.     

Effect of transcutaneous electrical nerve stimulation on onset of axillary plexus block

We examined the effect of high frequency transcutaneous electrical nerve stimulation on the onset of brachial plexus block. Three groups of patients scheduled for surgery of the hand had a local anaesthetic block performed with 40 ml mepivacaine 1.5% using the axillary approach. After injection of the local anaesthetic transcutaneous electrical nerve stimulation was applied for 15 min either to the median nerve or the ulnar nerve; no stimulation was applied in the control group. Before and for 45 min after, the injection of local anaesthetic touch perception, pin prick, motor strength andskin temperature were tested by a blinded investigator in the areas supplied by the median, musculocutaneous, radial and ulnar nerves. There were no differences in the onset of block between the groups. Thus, the frequency-dependent action of local anaesthetics could not be demonstrated.     

二期多组神经移位治疗臂丛神经根性撕脱伤的临床应用和疗效

目的 分析治疗臂丛神经根性撕脱伤的二期手术方法及其效果。方法 2001年8月～2003年4月8例全臂丛神经根性撕脱伤患者，年龄18～38岁。平均伤后6个月内，均应用以下术式治疗。手术步骤：一期手术，膈神经移位至臂丛上干前股，副神经移位至肩胛上神经；健侧C7神经移位至患侧尺神经；二期手术，第4、5、6、7肋间神经移位至桡神经和胸背神经，健侧C7神经经尺神经移位至正中神经。结果 术后8例均获随访，时间为二期术后l3～25个月，平均21个月。所有患者均有不同程度恢复，相应靶肌肉肌力恢复大于或等于M3为有效恢复，肌皮神经有效恢复6例，恢复率为75．0％；肩胛上神经有效恢复3例，恢复率为37．5％；桡神经有效恢复3例，恢复率为37．5％；胸背神经有效恢复6例，恢复率为75．0％；正中神经有效恢复5例，恢复率为62．5％。感觉恢复情况：正中神经感觉4例为S3，3例为S2，1例为S1。结论 二期多组神经移位安全有效，对部分早期臂丛神经损伤并要求缩短手术次数的患者，是一种可选择的方法。     

超声引导下不同入路臂丛神经阻滞在桡骨远端手术中效果的比较

目的 比较超声引导下不同入路臂丛神经阻滞(肌间沟、腋路、锁骨上)在桡骨远端手术中的麻醉效果. 方法 90例择期行“桡骨远端骨折切开复位内固定术”或“桡骨远端骨折术后内固定取出手术”的成年患者,在超声引导下行臂丛神经阻滞,按照随机数字表法分为3组(每组30例):肌间沟入路臂丛神经阻滞组(A组)、腋路臂丛神经阻滞组(B组)、锁骨上入路臂丛神经阻滞组(C组).记录操作时间、镇痛持续时间,测定桡神经、尺神经、正中神经、前臂外侧皮神经和前臂内侧皮神经分布区的痛觉消失时间,评价感觉阻滞效果、麻醉效果及并发症的发生情况. 结果 3组患者基本资料与操作时间比较,差异无统计学意义(P＞0.05).3组的镇痛持续时间差异无统计学意义(P＞0.05).3组桡神经、正中神经、前臂外侧皮神经痛觉消失时间差异均无统计学意义(P＞0.05).A组和C组患者尺神经痛觉消失时间比较[(21±6) min比(20±5) min],差异无统计学意义(P＞0.05),但均长于B组[(8±5)min](P＜0.05);A组和C组前臂内侧皮神经痛觉消失时间比较[(18±6) min比(17±6) min],差异亦无统计学意义(P＞0.05),但与B组[(10±6) min]比较,差异均有统计学意义(P＜0.05).B组麻醉效果优秀率最高(90％).A组和C组分别有2例和1例患者出现膈神经阻滞,B组有1例患者止血带不耐受. 结论 超声引导下腋路臂丛神经阻滞时尺神经及前臂内侧皮神经痛觉消失时间短,在桡骨远端手术中麻醉优秀率高、并发症少.     

同侧颈7神经根移位治疗臂丛上千根性撕脱伤的实验研究

目的 实验性比较同侧C7神经根全根移位与其他3种方法治疗臂丛上千根性撕脱伤的疗效.方法 120只SD大鼠建立上千根性撕脱伤模型后随机等分为4组,每组30只.(1)A组:同侧C7移位至上千+副神经至肩胛上神经;(2)B组:Oberlin手术(尺神经一束移位至肱二头肌支)+副神经至肩胛上神经+桡神经肱三头肌长头支至腋神经前支;(3)C组:膈神经移位至上千前股+副神经至肩胛上神经+颈丛运动支至上千后股;(4)D组:膈神经移位至上千前股+副神经至肩胛上神经,不作腋神经修复.术后3、6和12周每组取10只大鼠作Ochiai评分、Barth足错步试验、Terzis梳头试验及神经再生指标的榆测.结果 术后3周,A组3项行为学检测指标与3个对照组差异无统计学意义(P>0.017),腋神经电生理指标均显著优于3个对照组,其余各项腋神经及三角肌组织学指标均显著优于C组和D组,但与B组比较差异无统计学意义.A组除肌皮神经再生有髓神经纤维通过率显著优于C组外,其余肌皮神经及肱二头肌的电牛理与组织学检测指标与3个对照组比较差异无统计学意义.12周时,A组各项行为学观察、几乎全部腋神经和三角肌的电生理与组织学检测以及部分肌皮神经和肱二头肌的电生理与组织学检测指标均已显著优于3个对照组.结论 同侧C7神经根移位对治疗臂丛上千根性撕脱伤的实验性疗效显著.     

Possible donor nerves for axillary nerve reconstruction in dual neurotization for restoring shoulder abduction in brachial plexus injuries: a systematic review and meta-analysis

Restoring shoulder abduction is one of the main priorities in the surgical treatment of brachial plexus injuries. Double nerve transfer to the axillary nerve and suprascapular nerve is widely used and considered the best option. The most common donor nerve for the suprascapular nerve is the spinal accessory nerve. However, donor nerves for axillary nerve reconstructions vary and it is still unclear which donor nerve has the best outcome. The aim of this study was to perform a systematic review on reconstructions of suprascapular and axillary nerves and to perform a meta-analysis investigating the outcomes of different donor nerves on axillary nerve reconstructions. We conducted a systematic search of English literature from March 2001 to December 2020 following PRISMA guidelines. Two outcomes were assessed, abduction strength using the Medical Research Council (MRC) scale and range of motion (ROM). Twenty-two studies describing the use of donor nerves met the inclusion criteria for the systematic review. Donor nerves investigated included the radial nerve, intercostal nerves, medial pectoral nerve, ulnar nerve fascicle, median nerve fascicle and the lower subscapular nerve. Fifteen studies that investigated the radial and intercostal nerves met the inclusion criteria for a meta-analysis. We found no statistically significant difference between either of these nerves in the abduction strength according to MRC score (radial nerve 3.66?±?1.02 vs intercostal nerves 3.48?±?0.64, p?=?0.086). However, the difference in ROM was statistically significant (radial nerve 106.33?±?39.01 vs. intercostal nerve 80.42?±?24.9, p?<?0.001). Our findings support using a branch of the radial nerve for the triceps muscle as a donor for axillary nerve reconstruction when possible. Intercostal nerves can be used in cases of total brachial plexus injury or involvement of the C7 root or posterior fascicle. Other promising methods need to be studied more thoroughly in order to validate and compare their results with the more commonly used methods.

     

臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.