Ultrasound-guided block of the brachial plexus at the humeral canal

Purpose

Conduction block of the brachial plexus block at the humeral canal, as described by Dupre, has certain clinical indications. The aim of this preliminary study was to assess the feasibility of this technique under ultrasound guidance.

Methods

After ultrasound evaluation of the brachial plexus at the humeral canal in 61 adult volunteers, we performed ultrasound-guided blocks in another 20 adult patients. A linear 38 mm probe, 13–6 MHz, and a 50-mm insulated block needle were used to guide injection of lidocaine 1.5% with epinephrine.

Results

Ulnar and median nerves are superficial and located at similar depths. Ultrasound imaging showed the musculocutaneous nerve to be located dorsally. The radial nerve is dorsal to the plane of the musculocutaneous nerve. Relative to the brachial artery, the median nerve is situated between 12 and 1 o’clock in 66% of the cases. Relative to the basilic vein, the ulnar nerve is situated at 3 o’clock in 46% of the cases. The evaluated block sequence was radial, ulnar, musculocutaneous and median nerve; two points of puncture were mandatory, and 6.85 ± 0.37 min were required to perform the blocks. Sensory onset times were similar for the four nerves. Injectate volume was lower for the musculocutaneous nerve compared to other nerves (P < 0.05). All 20 patients experienced complete sensory and motor blocks.

Conclusion

We describe an approach to, and the feasibility of ultrasound-guided block of the brachial plexus at the humeral canal. Further study will be required to establish the effectiveness and the safety of this technique.     

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.     

Infraclavicular plexus block: multiple injection versus single injection

BACKGROUND AND OBJECTIVES: This prospective, randomized, and multicentered study was undertaken to evaluate the success rate of coracoid infraclavicular nerve block performed with a nerve stimulator when either 1 or 3 motor responses were sought. METHODS: Eighty patients who presented for elbow, forearm, or wrist surgery were randomly allocated to one of the following groups: in group 1 (single stimulation), 30 mL local anesthetic (LA) was injected after locating only 1 of the median, ulnar, or radial motor responses. In group 2 (multistimulation), 3 responses were located: musculocutaneous, median or ulnar, and radial response, corresponding, respectively, to the lateral, medial, and posterior cords. A total of 10 mL LA was injected on each response. Bupivacaine 0.5% and lidocaine 2% with epinephrine 1:200000 (1:1 vol) were used as the LA mixture. Sensory and motor blocks were tested by a blinded observer. RESULTS: Block duration was slightly increased in the multistimulation group (P =.004). The onset time of sensory and motor block was faster in each nerve distribution, particularly in the radial, musculocutaneous, and antebrachial nerves. The success of anesthesia increased in the multistimulation group. The success rate of the block, without any additional block, sedation, or general anesthesia, increased from 40% in the single stimulation group to 72.5% in the multistimulation group (P <.0001). If the brachial and antebrachial cutaneous nerves were not included in the evaluation, success rate reached 87.5%. CONCLUSIONS: We conclude that by performing an infraclavicular block with stimulation of all 3 cords of the brachial plexus, the success rate is higher than when only a single stimulation is used.     

Double- vs. single-injection infraclavicular plexus block in the emergency setting: higher success rate with lower volume of local anaesthetic

BACKGROUND AND OBJECTIVES: Infraclavicular plexus block has many advantages of particular interest in the emergency setting. However, the number of nerve stimulations needed to optimize the technique remains unclear. We evaluated both the local anaesthetic requirement and the success rate of Sim's derived infraclavicular plexus block performed with a nerve stimulator when either one or two responses were sought. METHODS: In this prospective study, 50 patients who presented for distal upper limb surgery were randomized into two groups: in Group 1, ropivacaine 0.75% 40 mL was injected when nerve stimulation elicited a distal motor response (median, ulnar or radial). In Group 2, only 30 mL of the same local anaesthetic was injected, 7 mL to the musculocutaneous nerve and 23 mL to the median, ulnar or radial nerves. Sensory and motor blocks were tested at 5-min intervals over 30 min. RESULTS: The time to perform the block was similar in both groups. The success rate of the block increased from 80% in the single-stimulation group to 92% in the double-stimulation group (not significant). The onset time of sensory and motor block was shorter and block extension was greater in ulnar, antebrachial cutaneous and brachial cutaneous nerve distributions in the multistimulation group (P < 0.05). CONCLUSIONS: We conclude that only 30 mL of local anaesthetic seems to be sufficient to ensure a high level of success when performing an infraclavicular block with stimulation of both the musculocutaneous nerve and median, ulnar or radial nerve.     

Dexamethasone added to lidocaine prolongs axillary brachial plexus blockade

Different additives have been used to prolong regional blockade. We designed a prospective, randomized, double-blind study to evaluate the effect of dexamethasone added to lidocaine on the onset and duration of axillary brachial plexus block. Sixty patients scheduled for elective hand and forearm surgery under axillary brachial plexus block were randomly allocated to receive either 34 mL lidocaine 1.5% with 2 mL of isotonic saline chloride (control group, n = 30) or 34 mL lidocaine 1.5% with 2 mL of dexamethasone (8 mg) (dexamethasone group, n = 30). Neither epinephrine nor bicarbonate was added to the treatment mixture. We used a nerve stimulator and multiple stimulations technique in all of the patients. After performance of the block, sensory and motor blockade of radial, median, musculocutaneous, and ulnar nerves were recorded at 5, 15, and 30 min. The onset time of the sensory and motor blockade was defined as the time between last injection and the total abolition of the pinprick response and complete paralysis. The duration of sensory and motor blocks were considered as the time interval between the administration of the local anesthetic and the first postoperative pain and complete recovery of motor functions. Sixteen patients were excluded because of unsuccessful blockade. The duration of surgery and the onset times of sensory and motor block were similar in the two groups. The duration of sensory (242 +/- 76 versus 98 +/- 33 min) and motor (310 +/- 81 versus 130 +/- 31 min) blockade were significantly longer in the dexamethasone than in the control group (P < 0.01). We conclude that the addition of dexamethasone to lidocaine 1.5% solution in axillary brachial plexus block prolongs the duration of sensory and motor blockade.     

Ultrasound-guided infraclavicular brachial plexus block: an alternative technique to anatomical landmark-guided approaches

BACKGROUND AND OBJECTIVES: Infraclavicular brachial plexus block has been used less than other approaches because of its less uniform landmarks and the necessity of a longer needle, which increases the patient's discomfort. To overcome these drawbacks, we applied ultrasound guidance to infraclavicular approach and prospectively evaluated its feasibility and usefulness in 60 patients undergoing upper extremity surgery. METHODS: A 7.0-MHz ultrasound probe was placed near the lower edge of the clavicle, and a transverse view of the subclavian artery and vein was visualized. Using a needle guide, a 23-gauge needle was advanced under real-time ultrasound guidance, and 1.5% lidocaine with 1:200,000 epinephrine was injected near the subclavian artery, 15 mm medially and 15 mm laterally to the artery. The extent of sensory and motor block was evaluated at 30 minutes after the injection. RESULTS: An adequate ultrasound image was obtained for all the patients. In 57 patients (95%), surgery was performed without supplementation of any other anesthetics or analgesics. The complete sensory block was obtained in 100% of patients for the musculocutaneous and medial antebrachial cutaneous nerves, 96.7% for the median nerve, and 95% for the ulnar and radial nerves. The complete motor block was achieved in 100% of patients for the musculocutaneous nerve, 96.7% for the median nerve, 90% for the ulnar nerve, and 93.3% for the radial nerve. No evidence of any complications was identified. CONCLUSIONS: Real-time ultrasound guidance facilitates accurate infraclavicular approach to the brachial plexus. It could be used as an alternative to the landmark-guided techniques.     

Evaluation of alkalinized lidocaine solution in brachial plexus blockade

The effect of alkalinization of lidocaine solution in brachial plexus blockade was evaluated in a double blind study. Commercial 1.5% lidocaine with epinephrine 1:200,000 (pH 5.72) was compared with an alkalinized solution of lidocaine (pH 7.12). 10mg·kg^–1 of each solution was administrated by the axillary perivascular technique in 34 adult patients scheduled for elective surgery. The onset and spread of sensory blockade and the intensity of motor blockade were determined. An alkalinized lidocaine solution produced more complete sensory blockade in all of four main nerves of the upper extremity as compared with the control lidocaine solution. The onset of sensory blockade in the musculocutaneous, radial, ulnar and median nerves was shortened 58%, 40%, 30% and 28%, respectively, by employing the alkalinized lidocaine solution. Also the analgesic onset in the radial and musculocutaneous nerves was significantly faster than the other two nerves (P < 0.05 and P < 0.01). Furthermore, the intensity of motor blockade was greatly potentiated when alkalinized lidocaine solution was employed. There was no significant increase in plasma concentration of lidocaine in patients who were given alkalinized solution.(Kanaya N, Imaizumi H, Matsumoto M, et al.: Evaluation of alkalinized lidocaine solution in brachial plexus blockade. J Anesth 5: 128–131, 1991)     

Brachial plexus blocks: a review of approaches and techniques

PURPOSE: The purpose of this narrative review is to summarize the evidence derived from randomized controlled trials (RCTs) regarding established approaches and techniques for brachial plexus anesthesia. SOURCE: Using the MEDLINE (January 1966 to November 2006) and EMBASE (January 1980 to November 2006) databases, key words "brachial plexus", "nerve blocks", "interscalene", "cervical paravertebral", "suprascapular", "supraclavicular", "infraclavicular", "axillary", "brachial canal" and "humeral canal" were searched for full text articles pertaining to the evaluation of recognized approaches and techniques for brachial plexus anesthesia. The search was limited to RCTs involving human subjects and published in the English language. Seventy-six RCTs were identified. PRINCIPAL FINDINGS: Many of the published studies were underpowered and contained various methodological limitations. We found that, for shoulder and proximal humeral surgery, interscalene and cervical paravertebral approaches to the brachial plexus appear to provide equally effective surgical anesthesia. Intersternocleidomastoid supraclavicular blocks are not associated with improved postoperative analgesia despite eliciting more complete anesthesia of the brachial plexus. For surgery at or below the elbow, an infraclavicular block may result in decreased performance time and block-related pain while providing similar efficacy compared to (multiple-stimulation) axillary and brachial canal approaches. With respect to technique, it is unclear if nerve stimulation provides a more effective interscalene block than elicitation of paresthesiae. For supraclavicular blocks, nerve stimulation with a minimal threshold of 0.9 mA is recommended, whereas a double-stimulation technique is optimal for infraclavicular blocks. For the axillary approach, a triple-stimulation technique, involving injections of the musculocutaneous, median and radial nerves, is the most effective option. CONCLUSIONS: Published reports of RCTs provide evidence to formulate limited recommendations regarding optimal approaches and techniques for brachial plexus anesthesia. Further well-designed and meticulously executed RCTs are warranted, particularly in light of new techniques involving ultrasound or combining neurostimulation and echoguidance.     

Fentanyl improves analgesia but prolongs the onset of axillary brachial plexus block by peripheral mechanism

We evaluated the effects of fentanyl added to lidocaine for axillary brachial plexus block in 66 adult patients scheduled for elective hand and forearm surgery. In this double-blinded study, all patients received 40 mL of 1.5% lidocaine with 1:200,000 epinephrine, injected into the brachial plexus sheath using the axillary perivascular technique, and they were randomized into three groups. Group 1 was given lidocaine containing 2 mL of normal saline plus 2 mL of normal saline IV. Patients in Group 2 received lidocaine containing 100 microg fentanyl plus 2 mL of normal saline IV. Group 3 patients received lidocaine containing 2 mL of normal saline plus 100 microg fentanyl IV. Sensory and motor blockade were evaluated by using a pinprick technique and by measuring the gripping force, respectively. The success rate of sensory blockade for radial and musculocutaneous nerves and the duration of the sensory blockade significantly increased in Group 2 (323 +/- 96 min) as compared with Group 1 (250 +/- 79 min). However, onset time of analgesia was prolonged in every nerve distribution by adding fentanyl to brachial plexus block. IV fentanyl had no effect on the success rate, onset, or duration of blockade. We conclude that the addition of fentanyl to lidocaine causes an improved success rate of sensory blockade but a delayed onset of analgesia, although this may be accounted for by the decreased pH caused by the fentanyl. Implications: It is still unclear whether the addition of a peripheral opioid is useful for nerve blockade in humans. Peripheral application of fentanyl to lidocaine for axillary brachial plexus blockade in this study provided an improved success rate of sensory blockade and prolonged duration.     

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.     

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.     

三种定位方法行臂丛神经阻滞的效果比较

目的探讨三种定位方法行臂丛神经阻滞的效果。方法选择择期上肢手术患者120例,随机均分成三组:超声引导组(A组)、神经刺激器组(B组)、传统方法组(C组),局麻药为2%盐酸氯普鲁卡因30ml。记录肌皮神经、桡神经、正中神经、尺神经阻滞的起效时间,并评价其阻滞完善率;评定麻醉效果(优、良、差),记录并发症。结果 A组神经阻滞起效时间较短,而C组起效时间较长,A组和B组明显短于C组,且A组短于B组(P<0.01)。A组神经阻滞完善率均接近100%,明显高于B组和C组(P<0.05或P<0.01)。麻醉效果优等率A组为95%,B组为75%,C组为47.5%,A组明显高于B、C组(P<0.05或P<0.01)。A、B组各有1例,C组有3例并发症,但三组均未出现严重并发症。结论超声引导下臂丛神经阻滞较神经刺激器辅助和传统方法下的阻滞效果良好,起效时间更短,提高了麻醉安全性和有效性。     

Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion

PURPOSE: To report the results of a surgical technique of nerve transfer to reinnervate the brachialis muscle and the biceps muscle to restore elbow flexion after brachial plexus injury. METHODS: Retrospective review was performed on 6 patients who had direct nerve transfer of a single expendable motor fascicle from both the ulnar and median nerves directly to the biceps and brachialis branches of the musculocutaneous nerve. Assessment included degree of recovery of elbow flexion and ulnar and median nerve function including pinch and grip strengths. RESULTS: Clinical evidence of reinnervation was noted at a mean of 5.5 months (SD, 1 mo; range, 3.5-7 mo) after surgery and the mean follow-up period was 20.5 months (SD, 11.2 mo, range, 13-43 mo). Mean recovery of elbow flexion was Medical Research Council grade 4+. Postoperative pinch and grip strengths were unchanged or better in all patients. No motor or sensory deficits related to the ulnar or median nerves were noted and all patients maintained good hand function. No patients required additional procedures to further improve elbow flexion strength. CONCLUSIONS: Transfer of expendable motor fascicles from the ulnar and median nerves successfully can reinnervate the biceps and brachialis muscles for strong elbow flexion. The reinnervation of the brachialis muscle, the primary elbow flexor, as well as the biceps muscle provides an additional biomechanical advantage that accounts for the excellent elbow flexion strength obtained using this technique. Direct coaptation of the nerve fascicles was performed without the need for nerve grafts and there was no functional or sensory donor morbidity.     

Neurotization of the biceps muscle by end-to-side neurorraphy between ulnar and musculocutaneous nerves. A series of five cases

Three patients with avulsed C5, C6, and C7 roots and two patients with avulsed C5 and C6 roots after trauma of the brachial plexus, were treated by neurotization of the biceps using nerve fibers derived from the ulnar nerve and obtained by end-to-side neurorraphy between the ulnar and musculocutaneous nerves. The age of patients ranged from 19 to 45. The interval between the accident and surgery was 2 to 13 months. Return of biceps contraction was observed 4 to 6 months after surgery. Four patients recovered grade 4 elbow flexion. One 45-year-old patient did not obtain any biceps contraction after 9 months.     

Infraclavicular block with lateral approach and nerve stimulation: extent of anesthesia and adverse effects.

BACKGROUND AND OBJECTIVES: The infraclavicular approach to the brachial plexus is little used despite theoretical advantages of the technique. Using a vertical paracoracoid approach, we assessed the extent of the sensory block and the incidence of adverse effects. METHODS: After obtaining informed consent, 100 patients undergoing surgical procedures distal to the elbow were evaluated. The block was performed using a peripheral nerve stimulator. The puncture site was located in the infraclavicular fossa; the direction of the insulated needle was perpendicular to the skin. Motor response was sought in the hand or wrist at < or = 0.6 mA. A total of 40 mL of 1.5% mepivacaine was administered as a single injection. The sensory block was evaluated every 5 minutes for 30 minutes before surgery in the cutaneous distribution of terminal branches of the brachial plexus. RESULTS: When one considers the cutaneous distributions of the median, ulnar, radial, and musculocutaneous nerves, the success rate was 89% for surgery without need for additional peripheral nerve blocks or general anesthesia. In contrast, cutaneous areas innervated by the axillary and medial cutaneous nerves were rarely anesthetized. We were unable to demonstrate a correlation between the intensity of the stimulation and the success of the block. On the other hand, a correlation was found between tourniquet sensation and the absence of anesthesia of the medial cutaneous nerve of the arm. Local anesthetic toxicity, Horner's syndrome, and vascular puncture were respectively observed in 1%, 4%, and 5% of cases. The depth of the needle introduction was correlated with the body mass index (P <.001; r =.63). CONCLUSION: Single injection infraclavicular block, using a vertical paracoracoid approach, appears suitable for surgery distal to the elbow. Selective anesthesia of the medial cutaneous nerve is useful in improving tolerance of the tourniquet.     

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.     

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.     

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.     

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.     

Brachial plexus anatomy

The brachial plexus may be visualized simply as beginning with five nerves and terminating in five nerves. It begins with the anterior rami of C5, C6, C7, C8, and the first thoracic nerve. It terminates with the formation of the musculocutaneous, median, ulnar, axillary, and radial nerves. The intermediate portions are displayed in sets of threes: three trunks are formed, followed by three divisions, then three cords. Each trunk gives rise to two divisions and each cord gives rise to two branches. The lateral cord divides into the musculocutaneous nerve and the lateral branch of the median nerve. The medial cord divides into the medial branch of the median nerve and the ulnar nerve. The posterior cord divides into the axillary and the radial nerves. The anatomy of the brachial plexus can be confusing, especially because of frequent variations in length and caliber of each of its components.