A comparison of four stimulation patterns in axillary block

BACKGROUND AND OBJECTIVES: Insufficient spread of the local anesthetic toward the retroarterial region of the neurovascular space may be responsible for inconsistent anesthesia of the upper limb after single-injection axillary block. We hypothesized that injection of the local anesthetic on a single radial-nerve stimulation would produce the same extent of anesthesia as either a single median-nerve stimulation, a double-stimulation technique (radial and musculocutaneous nerves), or a triple-stimulation technique (radial, musculocutaneous, and median nerves). METHODS: One hundred twenty patients were randomly assigned to receive an axillary block by either median-nerve, radial-nerve, radial-nerve plus musculocutaneous-nerve, or triple-nerve stimulation with 40 mL of plain 1.5% mepivacaine. Patients were assessed for sensory block by the pinprick method at 5 and 20 minutes. RESULTS: Radial-nerve stimulation produced more extensive anesthesia than did median-nerve stimulation. The rate of anesthesia at 20 minutes in the median-nerve cutaneous distribution was similar after median-nerve stimulation or radial-nerve stimulation. The ulnar nerve was more frequently blocked at 20 minutes after radial-nerve stimulation than after median-nerve stimulation. Extent of anesthesia at 20 minutes after radial-nerve plus musculocutaneous-nerve stimulation was similar to that produced by triple-nerve stimulation, except for lower rates of anesthesia that corresponded to the median nerve. All of the differences were statistically significant. CONCLUSIONS: Musculocutaneous-nerve stimulation and radial-nerve stimulation play predominant roles in the success of axillary brachial plexus block, although a triple-nerve stimulation technique is still required to produce complete anesthesia of the upper limb.     

Multiple-injection axillary brachial plexus block: A comparison of two methods of nerve localization-nerve stimulation versus paresthesia

We conducted this prospective study to compare the onset time and the success rate of a multiple-injection axillary brachial plexus block performed by using two methods of nerve localization: paresthesia elicitation or nerve stimulation. Each of the major nerves of the plexus was located by elicitation of a paresthesia (Group PAR; n = 50) or by nerve stimulation (Group PNS; n = 50) and injected with 10 mL of local anesthetic solution. Time to perform the block, onset time of the primary block, time to achieve readiness for surgery, and total anesthetic time were significantly shorter in Group PNS than in Group PAR. The incidence of complete block was larger in Group PNS than in Group PAR (91% vs 76%; P: < 0. 05), and this was related to a larger success rate for anesthetizing the radial and the musculocutaneous nerves (P: < 0.05). The frequency of venous puncture was larger in Group PAR (P: < 0.05). For multiple-injection axillary brachial plexus block, we conclude that nerve stimulation resulted in a greater success rate and a faster onset than paresthesia elicitation, and it should be considered when the radial and musculocutaneous nerve distributions are involved in the surgical area. IMPLICATIONS: Two methods of nerve localization were compared when performing an axillary brachial plexus block by the multiple-injection technique. Nerve stimulation provided a faster onset and a greater incidence of complete block, related to a better success rate for anesthetizing the radial and the musculocutaneous nerves, than paresthesia elicitation.     

A comparison of proximal and distal radial nerve motor responses in axillary block using triple stimulation

BACKGROUND AND OBJECTIVES: Stimulation of the radial nerve at the axilla may cause either a proximal movement (forearm extension) or distal movements (supination, wrist or finger extension). In the most recent studies on axillary block, only a distal twitch was accepted as valid. However, this approach was based only on clinical experience. The aim of this study was to verify if a proximal motor response can be considered a satisfactory endpoint. METHODS: This was a prospective, randomized, double-blinded study. One hundred fifty patients received a triple-injection axillary brachial plexus block in which the radial nerve was located by a proximal (group PROX) or a distal motor response (group DIST). Patients were assessed for sensory and motor block of the branches of the radial nerve by a blinded investigator at 5-minute intervals over 30 minutes. RESULTS: An 81% success rate for anesthetizing the sensory distal branches of the radial nerve was seen in group PROX; a significantly higher success rate was recorded in group DIST (95%). The onset time of sensory block for the distal branches of the radial nerve was significantly shorter in group DIST (9.9 +/- 6 v 15.4 +/- 7 minutes). The time to perform the block was slightly shorter and the localization of the nerve simpler in group PROX. The overall block success rate was not significantly different in the 2 groups. CONCLUSIONS: Local anesthetic injection at the proximal radial twitch significantly reduces the efficacy and prolongs the onset time of the radial nerve block. Searching for distal response is significantly more difficult and time consuming than searching for proximal response. However, it does not significantly increase patient discomfort or adverse effects.     

A comparison of injection at the ulnar and the radial nerve in axillary block using triple stimulation

BACKGROUND AND OBJECTIVES: A triple-stimulation technique for axillary block consists of the localization and injection of 2 nerves, median and musculocutaneous, which lie superior to the axillary artery, and of 1 nerve, the radial, which lies inferior. However, in some patients, the ulnar nerve is located first during the search for the radial nerve. The aim of this study was to verify if an ulnar motor response could be considered a satisfactory endpoint as a radial motor response. METHODS: This study was a prospective, randomized, double-blinded study. Ninety patients received a triple-injection axillary brachial plexus block in which the radial nerve (group RAD) or the ulnar nerve (group ULN) was located and injected inferior to the axillary artery. Patients were assessed for sensory and motor block by a blinded investigator at 5-minute intervals over 30 minutes. RESULTS: A statistically significant higher overall block success rate was recorded in group RAD (91% vs. 73%), and this result was related to a larger success rate for anesthetizing the radial nerve (95% vs. 77%). A statistically significant shorter onset time of sensory block for the radial nerve was recorded in group RAD versus group ULN (9 +/- 5 min vs. 16 +/- 7 min), whereas the reverse was true for the ulnar nerve (13 +/- 7 min for group RAD vs. 10 +/- 3 min for group ULN). The time to perform the block was slightly but statistically significantly shorter in group ULN (6.5 +/- 1.7 min vs. 7.8 +/- 1.8 min). CONCLUSIONS: Local anesthetic injection at the ulnar nerve significantly reduces the efficacy and prolongs the onset time of the radial-nerve block when triple-stimulation axillary block is performed.     

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 prospective, randomized comparison between ultrasound and nerve stimulation guidance for multiple injection axillary brachial plexus block

BACKGROUND: This prospective, randomized, blinded study tested the hypothesis that ultrasound guidance can shorten the onset time of axillary brachial plexus block as compared with nerve stimulation guidance when using a multiple injection technique. METHODS: Sixty American Society of Anesthesiology physical status I-III patients receiving axillary brachial plexus block with 20 ml ropivacaine, 0.75%, using a multiple injection technique, were randomly allocated to receive either nerve stimulation (group NS, n = 30), or ultrasound guidance (group US, n = 30) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, the need for general anesthesia (failed block) or greater than 100 microg fentanyl (insufficient block) to complete surgery, procedure-related pain, success rate, and patient satisfaction. RESULTS: The median (range) number of needle passes was 4 (3-8) in group US and 8 (5-13) in group NS (P = 0.002). The onset of sensory block was shorter in group US (14 +/- 6 min) than in group NS (18 +/- 6 min) (P = 0.01), whereas no differences were observed in onset of motor block (24 +/- 8 min in group US and 25 +/- 8 min in group NS; P = 0.33) and readiness to surgery (26 +/- 8 min in group US and 28 +/- 9 min in group NS; P = 0.48). No failed block was reported in either group. Insufficient block was observed in 1 patient (3%) of group US and 2 patients (6%) of group NS (P = 0.61). Procedure-related pain was reported in 6 patients (20%) of group US and 14 patients (48%) of group NS (P = 0.028); patient acceptance was similarly good in the two groups. CONCLUSION: Multiple injection axillary block with ultrasound guidance provided similar success rates and comparable incidence of complication as compared with nerve stimulation guidance.     

不同浓度罗哌卡因用于腋路臂丛神经阻滞的研究

目的探讨0.25%、0.3%、0.375%罗哌卡因用于臂丛神经阻滞的有效性和安全性,并与0.25%布比卡因对照.方法选择ASAⅠ-Ⅱ级准备行上肢手术的病人80例,随机分为4组,每组20例,分别用0.25%、0.3%、0.375%罗哌卡因和0.25%布比卡因40ml行臂丛神经阻滞,观察病人有无不适症状,并分别对感觉和运动进行评价.结果随着浓度增加罗哌卡因麻醉强度依次增加,40m10.25%罗哌卡因麻醉强度明显低于0.25%布比卡因,且满意率低,仅为85%;将罗哌卡因浓度提高到0.375%,显示出与0.25%布比卡因相当的麻醉强度,满意率则提高到100%.结论 0.25%罗哌卡因用于臂丛神经阻滞起效慢、满意率低,不是临床使用的适宜浓度;0.3%、0.375%罗哌卡因起效快,作用完善,副作用少,可推荐用于长时间臂丛神经阻滞,而以0.375%罗哌卡因最为适宜.     

A comparison of a triple-injection axillary brachial plexus block with the humeral approach

BACKGROUND AND OBJECTIVES: This prospective, randomized, and single-blind study compared effectiveness, performance, onset, and total anesthetic time and complications of the multiple axillary block (median, radial, and musculocutaneous nerves) with the humeral approach. METHODS: One hundred patients were randomly assigned to 2 groups. In group A (axillary) median, radial, and musculocutaneus nerves were located by a nerve stimulator and injections were made. In group H (humeral) all 4 terminal nerves of the brachial plexus were located and injections were made. A total of 40 mL mepivacaine of 1% was used. RESULTS: Complete sensory block of all 6 peripheral nerves occurred in 94% and 79% of patients in groups A and H, respectively (P < .05). The time to perform the block was shorter in group A (8 +/- 4 minutes v 11 +/- 4 minutes; P < .001); onset time was shorter in group A (16 +/- 8 minutes v 21 +/- 9 minutes; P < .05); total anesthetic time was shorter in group A (24 +/- 8 minutes v 33 +/- 10 minutes; P < .0001). Complete motor block was greater in group A (88% v 66%; P < .05). More vascular punctures occurred in group A (22% v 8%, P < .05). CONCLUSION: The triple-injection axillary block was more effective than the humeral approach as it was associated with more cases of sensory and complete motor block and gave shorter performance and onset times.     

A comparison between double-injection axillary brachial plexus block and midhumeral block for emergency upper limb surgery

In this prospective and randomized study, we compared a double-injection axillary (median and radial nerves) block with a midhumeral block in 90 patients undergoing emergency upper limb surgery. Time to perform the block, success rate, and patient tolerance were evaluated. The time to perform the block was 5 min longer in the midhumeral group. The success rate was similar in both groups (80% and 91% in groups axillary and midhumeral respectively), except for the musculocutaneous nerve. Patient tolerance was better in the axillary group. Double-injection axillary brachial plexus block is superior to midhumeral block for emergency hand surgery.     

Radial plus musculocutaneous nerve stimulation for axillary block is inferior to triple nerve stimulation with 2% mepivacaine

STUDY OBJECTIVE: To compare the extent of sensory and motor block with two different nerve stimulation techniques in axillary blocks. DESIGN: Prospective, randomized, investigator-blinded study. SETTING: Ambulatory surgery unit of a university hospital. PATIENTS: 60 ASA physical status I, II, and III patients undergoing surgery at or below the elbow. INTERVENTIONS: Patients receiving axillary block were randomized into two nerve stimulation groups with either radial plus musculocutaneous or triple nerve stimulation (radial, median, and musculocutaneous nerves). Thirty milliliters of plain 2% mepivacaine was given to all patients either in a single or fractionated dosing for radial or for radial and median nerves, according to group assignment. Five milliliters of plain 1% mepivacaine for the musculocutaneous nerve was given to all patients. MEASUREMENTS: Blocks were assessed at 10, 20, and 30 minutes. Rates of supplementation given as a result of insufficient surgical anesthesia were also noted. MAIN RESULTS: Statistically significantly higher rates of anesthesia at the cutaneous distributions of median and medial cutaneous of the arm nerves with multiple nerve stimulation at 30 minutes were found as compared with radial plus musculocutaneous nerve stimulation. The rate of supplementation was lower with multiple nerve stimulation. CONCLUSIONS: Radial plus musculocutaneous nerve stimulation showed lower efficacy of axillary block than did triple nerve stimulation when using 2% mepivacaine.     

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.     

Interpleural block - part 2

Interpleural blockade is effective in treating unilateral surgical and non-surgical pain from the chest and upper abdomen in both the acute and chronic settings. It has been shown to provide safe, high-quality analgesia after cholecystectomy, thoracotomy, renal and breast surgery, and for certain invasive radiological procedures of the renal and hepatobiliary systems. It has also been used successfully in the treatment of pain from multiple rib fractures, herpes zoster, complex regional pain syndromes, thoracic and abdominal cancer, and pancreatitis. The technique is simple to learn and has both few contra-indications and a low incidence of complications. In the second of two reviews, the authors cover the applications, complications, contra-indications and areas for future research.     

Comfort and satisfaction during axillary brachial plexus block in trauma patients: comparison of techniques

Study ObjectiveTo investigate the comfort and satisfaction of patients with trauma of the upper limb during two different techniques of axillary brachial plexus block, electrical nerve stimulation and fascial pop.DesignRandomized-prospective, observational study.SettingUniversity surgical center.Patients100 ASA physical status I and II patients undergoing surgery for trauma of the hand and forearm.InterventionsPatients received axillary brachial plexus block with a mixture of 0.5% bupivacaine and 2% lidocaine. They were then allocated to one of two groups to receive either electrical nerve stimulation (Group 1, n = 50), or fascial pop technique (Group 2, n = 50) for nerve location.MeasurementsData were collected on patient demographics, surgery, frequency of complications, and sedation required during the block. Discomfort during the block and surgical comfort were quantified by visual analog scale (0-10). Satisfaction was determined by the following scale: very satisfied, satisfied, dissatisfied, and very dissatisfied. Patients also indicated if in the future they would like to receive the same method of anesthesia.Main ResultsNo differences in demographic or surgical data were found. No serious complications were observed. Eighteen Group 1 patients (36%) and none in Group 2 needed sedation during the blocks. Discomfort during the procedures was greater in Group 1 than Group 2 (4.5 ± 1.2 vs 1.5 ± 1, P < 0.05), while patients reported good surgical comfort with both techniques (2.4 ± 2.9 vs 2.2 ± 2.1, NS). Eighteen patients in Group 1 and 48 patients in Group 2 would accept the same block for future surgery.ConclusionsIn trauma patients, the fascial pop technique is effective, reduces sedation during axillary brachial plexus block, and has a higher patient acceptance rate than the electrical nerve stimulation technique.     

A comparison of articaine and fentanyl-supplemented articaine for hemodialysis fistula creation under ultrasound-guided axillary block

The aim of this prospective randomized, double-blinded study was to evaluate the effect of fentanyl addition to articaine on the duration of sensory as well as motor blocks, and the duration of analgesia during hemodialysis fistula creation under ultrasound-guided axillary block. Fifty patients were randomly allocated to two groups, an articaine group (A), receiving 40 mL of articaine HCI (20 mg/mL) with 2 mL of isotonic sodium chloride solution, and an articaine-fentanyl group (AF), receiving 40 mL of articaine HCI (20 mg/mL) with 2 mL (100 μg) of fentanyl. The onset as well as the duration of sensory and motor blocks, the time necessary for first analgesic administration, the hemodynamic parameters, and the side effects were recorded. Three patients in Group A and two patients in Group AF due to incomplete block were excluded from the study. The duration of sensory and motor blocks was significantly longer in the AF group than in the A group. The first time for analgesic need was also significantly longer in group AF (363 ± 134 min) than in group A (244 ± 84 min) (p = 0.001). The addition of fentanyl did not improve the onset of sensory and motor block times. Hemodynamic parameters were similar in the two groups. In conclusion, the addition of fentanyl to articaine in axillary block prolongs the duration of sensory and motor blocks, as well as the time of first analgesic requirement.     

Patients' experiences with multiple stimulation axillary block for fast-track ambulatory hand surgery

BACKGROUND: Ambulatory axillary block by multiple nerve stimulation (MNS) is effective and time efficient, but may be rejected by patients because of block pain. This prospective study assessed patients' anxiety and acceptance of this block, identified which of the components of blocking procedure is most painful (i.v. line insertion, repeated needle passes, local anesthetic injection, or electrical stimulation) and recorded patients' anesthetic preferences for the future hand surgery. METHODS: Upon arrival at the day unit, 100 unpremedicated adult patients without previous experience of peripheral nerve stimulation indicated on the visual analog scale (VAS; 0-100) their anxiety about the block. The blocking procedure was then explained step-by-step. After inserting the i.v. line and freezing the skin in axilla, four terminal nerves (musculocutaneous, median, ulnar, radial) were electrolocated using an initial current of 2 mA and a target current of 0.1-0.5 mA. Pain caused by the individual components of blocking procedure was assessed on VAS before the start of surgery. On the day after the operation, the patients reassessed their anxiety for the next axillary block and indicated which anesthetic method (block alone, block plus sedation, or general anesthesia) they would prefer for the future hand surgery. RESULTS: Before the block, 59 patients admitted being anxious about regional block (median anxiety VAS=27), compared with 42 patients (anxiety VAS=10) postoperatively: P<0.01. Median intensity of electrical stimulation pain was significantly higher (VAS=16) than pain of local anesthetic injections (VAS=8), i.v. line insertion (VAS=6) and multiple needle passes (VAS=5). However, only 53 patients categorized electrolocation as painful. Twenty-seven reported discomfort but not pain, and 20 patients described the sensation as 'funny' or 'strange'. None of the patients had surgical pain during operation. Mean duration of surgery was 77 min, and of hospital stay 166 min. Ninety-eight patients would choose the same block for the future hand surgery, 13 of which would like sedation before the block, and two patients did not wish to be awake during any surgery. Ninety-five patients were satisfied with fast-tracking. CONCLUSIONS: Fear of block pain is diminished after experiencing the blocking procedure. Electrical stimuli was perceived as painful by 53% of patients, and this pain was more intense than with other block components. The majority of our patients would choose axillary block without sedation for future hand surgery and are satisfied with fast-tracking.     

Obliteration of the axillary artery after axillary block

A case of total obliteration of the axillary artery after axillary block is presented. This resulted from an accidental intramural injection of local anaesthetic (mepivacaine 1%, 40 ml, with adrenaline 1:200,000). Axillary block was performed using the loss of resistance technique with a blunt needle (45 degrees bevel). The diagnosis was made by palpation of the peripheral pulse and by comparison between the skin temperatures of each arm. The thrombosed part of the artery was successfully reconstructed with an autologous saphenous vein graft.