Axillary Plexus Research Articles

"Triceps Brachii Muscle Response to Neurostimulation of the Radial Nerve during Axillary Plexus Blockade: Clinical, Anatomical and Histological Correlation".

Axillary plexus blockade is a common technique in clinical practice with a well-known pattern of structures around the brachial artery. Historically, the only proper response to radial nerve stimulation was considered to be extension of the hand and wrist. Twenty-five axillary blockades were assessed by ultrasound and neurostimulation; the principal objective was to correlate the needle position over the radial nerve with the anatomical and histological structure of that nerve. During the procedure, the needle was directed in two ways to reach the medial or lateral margin of the nerve: above the brachial artery or beneath it. Once the needle reached the nerve, the current was augmented gradually until a response was elicited. For the cadaveric anatomical study, eight axillae were dissected and histological samples were examined. The response of the triceps brachii muscle differed significantly between the two approaches to the radial nerve (P < 0.001), and the mean intensity of stimulation was significantly lower when the nerve was accessed above the artery (0.44 ± 0.15 mA) than below it (0.57 ± 0.17 mA) (P = 0.015). A triceps brachii motor response occurs at lower current intensity and lower needle-nerve distance when the radial nerve is accessed above the artery and over the latissimus dorsi tendon. These findings were correlated with the topography of the radial nerve in the axillary fossa. Clin. Anat. 33:578-584, 2020. © 2019 Wiley Periodicals, Inc.

Comparision between the effects of dexmedtomedian and fentanyl as adjuvants to lidocain on axillary plexus blockplexus block

Comparision between the effects of dexmedtomedian and fentanyl as adjuvants to lidocain on axillary plexus blockplexus block

A Comparative Clinical Study of Ultrasonography-Guided Perivascular and Perineural Axillary Brachial Plexus Block for Upper Limb Surgeries.

Background:Axillary brachial plexus block (ABPB) is safest among other methods of brachial plexus block because of its ease and reliability. The two approaches of ultrasonography-guided ABPB are perivascular (PV) and perineural (PN).Aims:This study was conducted to compare primary outcomes such as performance time, onset of the block, number of needle passes, block success rate, duration of sensory and motor block, and complications between ultrasound-guided PV and PN ABPB in patients posted for upper limb surgeries.Settings and Design:This prospective randomized study was conducted on 106 patients American Society of Anesthesiologists Class I and II posted for forearm, wrist, and hand surgeries, who were allotted into Group PV and Group PN 53 each.Materials and Methods:In both methods, 20 mL of the drug was used. To start with, musculocutaneous nerve was blocked with 5 mL of the drug. In the PV technique, remaining 15 mL of the drug was deposited anterior and posterior to axillary artery, and in PN technique, 5 mL of the drug was injected around radial, ulnar, and median nerve.Statistical Analysis:Mann–Whitney and Chi-square test were used for statistical analysis.Results:Significant difference was observed between the two groups in performance time (PV – 8.647 ± 0.54 min and PN – 14.53 ± 0.20 min), onset time (PV – 19.48 ± 2.83 min and PN – 13.86 ± 1.81 min), and number of needle passes (PV – 2.30 ± 0.50 and PN – 4.91 ± 0.66). Other parameters were comparable in both the groups.Conclusions:Ultrasound-guided PV axillary plexus block is better than PN axillary plexus block with respect to performance time and number of needle passes; but onset time was shorter in PN block, with precaution eliminating the risk of complications.

Vascular access surgery can be safely performed in an ambulatory setting.

Ambulatory surgery is associated with lower costs, but there is lack of evidence of the safety for ambulatory vascular access surgery. The objective of this study is to substantiate the safety and effectiveness of performing vascular access surgery in an ambulatory setting. A review of our prospectively maintained database including all vascular access open surgeries (creations and repairs) performed by our Vascular Access Unit between 2013 and 2017 was compiled. Patient comorbidities, surgery details, hospital admission conditions, and 1-week and 1-month follow-up patency and complications (death, infection, bleeding, and readmission/reintervention) were scrutinized. In the last 5 years, 1414 vascular access procedures were performed (67.8% access creations, 32.2% previous access repairs) in 1012 patients. Most surgeries were performed under local anesthesia (59.2%) or axillary plexus block (38.4%) and mainly in an ambulatory setting, without overnight hospital stays (90.9%). During the first postoperative week follow-up, 9 cases (0.6%) needed readmission or reintervention; significant infection materialized in 11 (0.8%) and 10 cases (0.7%) showed noteworthy hematoma or bleeding, only three (0.2%) requiring reintervention. The primary composite endpoint of 24-h death and 1 week readmission, reintervention, infection, or bleeding was 1.9% (27 cases); 1-month access failure was 6.2%. After univariate analysis, ambulatory settings were not related to higher rates of complications or readmissions. Arteriovenous access surgery can be safely performed in an ambulatory setting, in spite of complex cases, comorbidities, or the increasing implementation of axillary plexus blocks. Surgical results and patency are good, and complications necessitating readmission remain very low.

Prolonged Analgesic Efficacy of Articaine with the Addition of Tramadol in Axillary Brachial Plexus Block.

Objectives:Articaine is a rapid-onset, short-duration, local anesthetic. The aim of this study was to study the effect of adding tramadol to articaine in an axillary block to prolong the analgesic effect.Methods:This study was conducted with 60 patients of American Association of Anesthesiologists classification I or II and aged 18 to 60 years who underwent hand or forearm surgery with an axillary plexus block using a nerve stimulation technique. The patients were randomized into 2 groups: Group A (n=30) received 40 mL 1% articaine and Group AT (n=30) was administered 40 mL 1% articaine with 100 mg tramadol. The onset of sensory block, motor block, duration of sensorial block and motor block, duration of analgesia and hemodynamic parameters were recorded before the block and 5, 10, 20, 30, 60, 120, 180 minutes after the local anesthetic injection.Results:The sensory block duration in Group AT (187.5±13.0 min) was significantly longer than that of group A (140.78±8.74 min) (p<0.02). The motor block duration in Group AT (137.4±3 min) was significantly longer than that seen in Group A (93.71±9.6 min) (p<0.01). The duration of analgesia was longer in Group AT (218.8±18.2 min) than in Group A (170.8±17.2 min) (p<0.05). In group AT, 2 patients experienced the side effect of nausea and 1 patient had hypotension in the postoperative period.Conclusion:This study demonstrated that the addition of 100 mg of tramadol to articaine used for an axillary plexus block prolonged analgesia.

Dexmedetomidine as an adjuvant to 0.5% ropivacaine in ultrasound-guided axillary brachial plexus block.

The aim of this study was to elucidate the effect of dexmedetomidine added to ropivacaine on the onset and duration of sensory and motor block and duration of analgesia of ultrasound-guided axillary brachial plexus block. Thirty-seven ASA physical status I-II patients with elective forearm and hand surgery under ultrasound-guided axillary brachial plexus block were randomly divided into 2 groups. Patients in ropivacaine-dexmedetomidine group (group RD, n=19) received 15mL of 0.5% ropivacaine with 100μg (1mL) dexmedetomidine, and patients in ropivacaine group (group R, n=18) received 15mL of 0.5% ropivacaine with 1mL of normal saline. Onset time and duration of sensory and motor block and duration of analgesia were assessed. Duration of sensory block (U-value=35, P<.001), duration of motor block (P=.001) and duration of analgesia (P<.001) were extended in group RD compared to group R. Onset time of sensory block in group RD was significantly faster than in group R (U-value=65.5, P=.001). Onset time of motor block showed no significant difference between the 2 groups (U-value=116.5, P=.096). Adverse reactions were reported only in group RD (bradycardia in 2 and hypotension in 3 patients). Our study indicated that dexmedetomidine 100μg as adjuvant on ultrasound-guided axillary plexus block significantly prolonged the duration of sensory block and analgesia, as well as accelerated the time to onset of sensory block. These results should be weighed against the increased risks of motor block prolongation, transient bradycardia and hypotension and allow for attentive optimism, only if prolonged clinical trials provide a definitive answer.

Severe Trampoline Injuries: Incidence and Risk Factors in Children and Adolescents.

Severe trampoline injuries in children and adolescents are rare; however, minor injuries are common and their incidence is increasing. Severe injuries are most commonly head and neck injuries. They may result in long-term morbidity. This study aimed to illustrate these severe injuries and to find out their incidence and risk factors. This is a population-based, prospective study in the Oulu region of Finland completed over 2 years (May 1, 2015 to April 31, 2017). All children (<16 years of age) with severe trampoline injuries were included. Cervical spine fractures, chest wall and skull fractures, lesions of internal organs, hip and knee dislocations, and permanent disorders of the peripheral veins or nerves were in prior defined as severe. Multiple jumpers, stunts, younger age, previous injuries, insufficient use of safety equipment, and lack of supervision were hypothesized as risk factors. There were 11 injured patients (10 boys). The annual incidence was 6.28/100,000 children <16 years of age. Mean age was 11.5 years. Severe injuries included five ligamentous cervical spine injuries and two sternal bone fractures. In addition, there were one lumbar spine ligament injury, two hip dislocations, and one severe axillary plexus nerve lesion. Eight out of 11 accidents were not seen by any adult and none of them happened under professional supervision. Most injuries (N = 8) happened by failed backflips. Most severe injuries happened in unsuccessful flips. Children should have an adult supervisor and flips should not be attempted.

Corrective Osteotomy for Symptomatic Clavicle Malunion Using Patient-specific Osteotomy and Reduction Guides.

Midshaft clavicular fractures are often treated nonoperatively with good reported clinical outcome in a majority of patients. However, malunion with shortening of the affected clavicle is not uncommon. Shortening of the clavicle has been shown to affect shoulder strength and kinematics with alteration of scapular position. Whereas the exact clinical impact of these factors is unknown, the deformity may lead to cosmetic and functional impairment as for example pain with weight-bearing on the shoulder girdle. Other reported complications of clavicular malunion include thoracic outlet syndrome, subclavicular vein thrombosis, and axillary plexus compression. Corrective osteotomy has therefore been recommended for symptomatic clavicular malunions, generally using plain x-rays for planning the necessary elongation. Particularly in malunited multifragmentary fractures it may be difficult to exactly determine the plane of osteotomy intraoperatively to restore the precise anatomic shape of the clavicle. We present a technique for corrective osteotomy using preoperative computer planning and 3-dimensional printed patient-specific intraoperative osteotomy and reduction guides based on the healthy contralateral clavicle.

Skin Perfusion Changes within 12 h after Axillary Plexus Block

Background/Purpose: An improvement of the blood flow would be beneficial in microvascular upper-extremity reconstruction and in digit replantation. In the present work, skin perfusion changes and their duration due to axillary plexus block were quantified. Methods: The peripheral blood flow of the upper extremities in 20 patients undergoing trapeziectomy under axillary plexus block was analyzed. Results: Laser Doppler spectrophotometry was used to measure perfusion factors over a 12-h period, with the contralateral hand acting as the control. Axillary plexus block produced a significant increase of peripheral oxygen saturation (117 ± 35% vs. control 93 ± 22%, p = 0.019), peripheral blood flow (220 ± 166% vs. 130 ± 77%, p = 0.037), and velocity (164 ± 58% vs. 117 ± 45%, p = 0.011). Conclusion: Axillary plexus block produces an improvement of peripheral tissue oxygen saturation of the upper extremities over the first 6 h after the inception of anesthesia. This suggests a potential benefit especially for critically perfused tissues.

Individual duration of axillary brachial plexus block is unpredictable: a prospective double centered observational study.

The duration of effect for axillary plexus block using ropivacaine is highly variable. The available literature does not offer any plausible means of predicting time of block offset for individual patients, making it difficult to give accurate information and plan postoperative analgesics. This study was designed to identify factors influencing axillary plexus block offset time. A total of 92 patients participated in this prospective double centred observational study. All patients were scheduled for axillary plexus block with ropivacaine 0.75% and subsequent block duration was recorded. Mean time of axillary plexus block offset was 13.5 hours, with a range of 4.8 to 25.4 hours. No statistical significant differences in offset time was seen with regard to gender, age, body weight, BMI and ASA-classification. A trend for increasing duration of blocks associated with increasing age was observed. No statistically significant difference was identified in block duration between blocks performed with nerve stimulator guidance versus ultrasound guidance. Similarly, neither dose nor volume of ropivacaine 0.75% was identified as a factor influencing block duration. This prospective study demonstrates a large inter individual variation in time of axillary plexus block offset using ropivacaine 0.75%. The lack of association between offset time and both demographic and block performance factors, makes predictability of individual duration of axillary plexus blocks in clinical practice extremely difficult. We suggest that all patients should be made aware of such variability in duration prior to block placement.

Quantification of the vasodilatory effect of axillary plexus block. A prospective controlled study

BackgroundAxillary plexus block is a common method for regional anesthesia, especially in hand and wrist surgery. Local anesthetics (e.g., mepivacaine) are injected around the peripheral nerves in the axilla. A vasodilatory effect due to sympathicolysis has been described, but not quantified. Materials and methodsIn a prospective controlled study between October 2012 and July 2013, we analyzed 20 patients with saddle joint arthritis undergoing trapeziectomy under axillary plexus block. Patients received a mixture of mepivacaine 1% and ropivacaine 0.75% in a 3:1 ratio. The measurements were carried out on the plexus side and the contralateral hand, which acted as the control. Laser-Doppler spectrophotometry (oxygen to see [O2C] device) was used to measure various perfusion factors before and after the plexus block, after surgery and in 2-h intervals until 6 h postoperatively. ResultsCompared with the contralateral side, the plexus block produced an enhancement of tissue oxygen saturation of 117.35 ± 34.99% (cf. control SO2: 92.92 ± 22.30%, P < 0.010) of the baseline value. Furthermore, blood filling of microvessels (rHb: 131.36 ± 48.64% versus 109.12 ± 33.25%, P < 0.0062), peripheral blood flow (219.85 ± 165.59% versus 129.55 ± 77.12%, P < 0.018), and velocity (163.86 ± 58.18% versus 117.16 ± 45.05%, P < 0.006) showed an increase of values. ConclusionsAxillary plexus block produces an improvement of peripheral tissue oxygen saturation of the upper extremity over the first 4 h after the inception of anesthesia.

Effect of warming bupivacaine 0.5% on ultrasound-guided axillary plexus block. Randomized prospective double-blind study

ObjectiveTo evaluate the effect of warming bupivacaine 0.5% on ultrasound-guided axillary brachial plexus block. Study designProspective, randomized, double-blind. Patients and methodsEighty patients undergoing elective or emergency surgery beyond the distal third of the upper limb were divided into two groups of 40 patients: the warm group received 15mL bupivacaine 0.5% heated to 37°C; the cold group received 15mL 0.5% bupivacaine stored for at least 24hours in the lower compartment of a refrigerator at 13–15°C. Onset and duration of sensory and motor blocks were evaluated every 5minutes for 40minutes. Postoperative pain was evaluated at 1, 3, 6, 12 and 24hours. Effective analgesia time was recorded as the interval between anesthetic injection and the first analgesia requirement (VAS>30mm). ResultsTime to onset of sensory and motor block was significantly shorter in the warm group, and mean duration of sensory and motor block and of postoperative analgesia significantly longer. ConclusionWarming bupivacaine 0.5% to 37°C accelerated onset of sensory and motor block and extended action duration.

Single, double or multiple-injection techniques for non-ultrasound guided axillary brachial plexus block in adults undergoing surgery of the lower arm.

Regional anaesthesia comprising axillary block of the brachial plexus is a common anaesthetic technique for distal upper limb surgery. This is an update of a review first published in 2006 and previously updated in 2011 and 2013. To compare the relative effects (benefits and harms) of three injection techniques (single, double and multiple) of axillary block of the brachial plexus for distal upper extremity surgery. We considered these effects primarily in terms of anaesthetic effectiveness; the complication rate (neurological and vascular); and pain and discomfort caused by performance of the block. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 3), MEDLINE (1946 to April Week 1 2016), Embase (1947 to April 18 2016) and reference lists of trials. We contacted trial authors. The date of the last search was April 2016 (updated from March 2013). We included randomized controlled trials that compared double with single-injection techniques, multiple with single-injection techniques, or multiple with double-injection techniques for axillary block in adults undergoing surgery of the distal upper limb. We excluded trials using ultrasound-guided techniques. Independent study selection, 'Risk of bias' assessment and data extraction were performed by at least two investigators. We undertook meta-analysis. We included one new trial involving 45 participants in this updated review. In total we included 22 trials involving a total of 2193 participants who received regional anaesthesia for hand, wrist, forearm or elbow surgery. 'Risk of bias' assessment indicated that trial design and conduct were generally adequate; the most common areas of weakness were in blinding and allocation concealment.Nine trials comparing double versus single injections showed a statistically significant decrease in primary anaesthesia failure (risk ratio (RR) 0.55, 95% confidence interval (CI) 0.34 to 0.89, high-quality evidence). Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique.Nine trials comparing multiple with single injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.25, 95% CI 0.14 to 0.42, high-quality evidence). Pooled data from five trials also showed a significant decrease in incomplete motor block (RR 0.61, 95% CI 0.39 to 0.96, high-quality evidence) in the multiple-injection group.Twelve trials comparing multiple versus double injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.27, 95% CI 0.19 to 0.39, high-quality evidence). Pooled data from six trials also showed a significant decrease in incomplete motor block (RR 0.55, 95% CI 0.36 to 0.85, high-quality evidence) in the multiple injection group.Tourniquet pain was significantly reduced with multiple injections compared with double injections (RR 0.53, 95% CI 0.33 to 0.84, high-quality evidence). Otherwise there were no statistically significant differences between groups in any of the three comparisons on secondary analgesia failure, complications and patient discomfort. Compared with multiple injections, the time for block performance was significantly shorter for single injection (MD 3.33 minutes, 95% CI 2.76 to 3.90) and double injections (MD 1.54 minutes, 95% CI 0.80 to 2.29); however there was no difference in time to readiness for surgery. This review provides evidence that multiple-injection techniques using nerve stimulation for axillary plexus block produce more effective anaesthesia than either double or single-injection techniques. However, there was insufficient evidence to draw any definitive conclusions regarding differences in other outcomes, including safety.

The efficacy of simultaneous bilateral axillary brachial plexus block under the guidance of neurostimulator or ultrasound: a prospective study.

This study was designed to investigate the risk of local anesthetic toxicity and efficacy of simultaneous bilateral axillary brachial plexus block performed under the guidance of ultrasound or a neurostimulator. One hundred and twenty patients who were anesthetized with bilateral axillary plexus block simultaneously between February 2012 and March 2014 were enrolled in the study. The patients were anesthetized under the guidance of a neurostimulator (group N, n=60) or ultrasound (group U, n=60). The block performance time, procedure-related pain, adverse events, total and free plasma concentrations of ropivacaine, and other data were recorded. The comparison was analyzed statistically. The block performance time, and onset of the sensory and motor block, of group N was longer than that of group U (p<0.001). The procedure-related pain of group N was more serious than that of group U (p<0.05). The patient satisfaction rate of group U was higher than that of group N (p<0.05). The total plasma concentrations of ropivacaine in group N were comparable to those of group U, except for the value at 50min after injection (p<0.05). The free plasma concentrations of ropivacaine of group N at 5min were significantly higher than that of group U (p<0.001). No apparent serious adverse events were observed perioperatively in both groups. Simultaneous bilateral axillary brachial plexus block guided by neurostimulator or ultrasound in bilateral distal upper extremity surgery seems to have a low risk of local anesthetic toxicity and to be effective. The ultrasound-guided block is superior in terms of providing the same degree of anesthesia with shorter duration, less pain, and faster onset of sensory and motor blockades, which is important in clinical practice.

Upper extremity nerve block: how can benefit, duration, and safety be improved? An update.

Upper extremity blocks are useful as both sole anaesthesia and/or a supplement to general anaesthesia and they further provide effective postoperative analgesia, reducing the need for opioid analgesics. There is without doubt a renewed interest among anaesthesiologists in the interscalene, supraclavicular, infraclavicular, and axillary plexus blocks with the increasing use of ultrasound guidance. The ultrasound-guided technique visualising the needle tip and solution injected reduces the risk of side effects, accidental intravascular injection, and possibly also trauma to surrounding tissues. The ultrasound technique has also reduced the volume needed in order to gain effective block. Still, single-shot plexus block, although it produces effective anaesthesia, has a limited duration of postoperative analgesia and a number of adjuncts have been tested in order to prolong analgesia duration. The addition of steroids, midazolam, clonidine, dexmedetomidine, and buprenorphine has been studied, all being off-label when administered by perineural injection, and the potential neurotoxicity needs further study. The use of perineural catheters is an effective option to improve and prolong the postoperative analgesic effect. Upper extremity plexus blocks have an obvious place as a sole anaesthetic technique or as a powerful complement to general anaesthesia, reducing the need for analgesics and hypnotics intraoperatively, and provide effective early postoperative pain relief. Continuous perineural infusion is an effective option to prolong the effects and improve postoperative quality.

A New Proposal for Management of Severe Frostbite in the Austere Environment

Despite advances in outdoor clothing and medical management of frostbite, individuals still experience catastrophic amputations. This is a particular risk for those in austere environments, due to resource limitations and delayed definitive treatment. The emerging best therapies for severe frostbite are thrombolytics and iloprost. However, they must be started within 24 hours after rewarming for recombinant tissue plasminogen activator (rt-PA) and within 48 hours for iloprost. Evacuation of individuals experiencing frostbite from remote environments within 24 to 48 hours is often impossible. To date, use of these agents has been confined to hospitals, thus depriving most individuals in the austere environment of the best treatment. We propose that thrombolytics and iloprost be considered for field treatment to maximize chances for recovery and reduce amputations. Given the small but potentially serious risk of complications, rt-PA should only be used for grade 4 frostbite where amputation is inevitable, and within 24 hours of rewarming. Prostacyclin has less risk and can be used for grades 2 to 4 frostbite within 48 hours of rewarming. Until more field experience is reported with these agents, their use should probably be restricted to experienced physicians. Other modalities, such as local nerve blocks and improving oxygenation at high altitude may also be considered. We submit that it remains possible to improve frostbite outcomes despite delayed evacuation using resource-limited treatment strategies. We present 2 cases of frostbite treated with rt-PA at K2 basecamp to illustrate feasibility and important considerations.

Feasibility, efficacy, and safety of ultrasound-guided axillary plexus blockade in pediatric patients with epidermolysis bullosa dystrophica.

In patients suffering from epidermolysis bullosa dystrophica (DEB), the most severe form of epidermolysis bullosa, trauma or friction cause separation of the skin from underlying tissue with consecutive painful blisters, scarifications, contractures, and pseudosyndactyly. To retain functionality of the hands surgical procedures are necessary. Anesthesia is challenging as difficult airways make general anesthesia risky. Regional anesthesia is considered controversial in patients with EB as accidental subcutaneous injections can cause severe blisters. As ultrasound-guided procedures became standard of care this might have changed however. In this case series, we describe feasibility, efficacy, and safety of ultrasound-guided plexus axillaris block in DEB patients undergoing hand surgery. We performed a retrospective analysis of the charts of all children with DEB undergoing hand surgery under plexus axillaris block and sedation between 2009 and 2013 in our institution. Nineteen procedures in nine children were performed. Induction of anesthesia (securing monitoring, sedation, plexus block) took a mean time of 34 min. Perioperative analgesia was adequate in all procedures. No complications such as airway incidents, conversion to general anesthesia, movement during surgery, incomplete block, or formation of new blisters were seen. Ultrasound-guided plexus axillaris block in DEB patients undergoing hand surgery in our institution has been feasible, effective, and safe.

Pain relief after ambulatory hand surgery: A comparison between dexmedetomidine and clonidine as adjuvant in axillary brachial plexus block: A prospective, double-blinded, randomized controlled study.

Background:For ages various adjuvants have been tried to prolong axillary brachial plexus block. We compared the effect of adding dexmedetomidine versus clonidine to ropivacaine for axillary brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia.Materials and Methods:A total of 90 patients (20-40 years) posted for ambulatory elective hand surgery under axillary brachial plexus block were divided into two equal groups (groups ropivacaine dexmedetomidine [RD] and ropivacaine clonidine [RC]) in a randomized, double-blind fashion. In group RD (n = 45) 30 ml 0.5% ropivacaine + 100 μg of dexmedetomidine and group RC (n = 45) 30 ml 0.5% ropivacaine + 75 μg clonidine were administered in axillary plexus block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics and side-effects were recorded for each patient.Results:Though with similar demographic profile in both groups, sensory and motor block in group RD (P < 0.05) was earlier than group RC. Sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RD (P < 0.05) than group RC. Postoperative VAS value at 18 h were significantly lower in group RD (P < 0.05). Intraoperative hemodynamics were insignificantly lower in group RD (P < 0.05) without any appreciable side-effects.Conclusion:It can be concluded that adding dexmedetomidine to axillary plexus block increases the sensory and motor block duration and time to first analgesic use, and decreases total analgesic use with no side-effects.

The relationship of the musculocutaneous nerve to the brachial plexus evaluated by MRI

Axillary plexus blocks (AXB) are widely used for upper limb operations. It is recommend that AXB should be performed using a multiple injection technique. Information about the course and position of the musculocutaneous nerve (MCN) is of relevance for AXB performance. The objective of this study was to examine the position of the MCN and its relationship to the axillary sheath using MRI. 54 patients underwent an AXB with 40 ml of local anaesthetic before MRI examination. The course of the MCN and the position where it left the axillary sheath and perforated the coracobrachial muscle (MCN exit point), in relation to the axillary artery and the block needle insertion point in the axillary fold, were recorded. The MCN was seen clearly in 23, partly in 26, and not identified in five patients at the MCN exit point. The mean distance from the insertion point of the block needle in the axillary fold to the MCN exit point was 36.8 mm (SD = 18.9, range: 0–90.5). In 37 patients the MCN exit point was positioned inside the Q1 quadrant (lateral anterior to the axillary artery) and in 11 patients inside the Q2 quadrant (medial anterior to the axillary artery). There is a wide variability as to where the musculocutaneous nerve (MCN) leaves the axillary sheath. Therefore multiple injection techniques, or the use of a proximally directed catheter, should be appropriate to block the MCN.

Ultrasound guidance improves the success rate of axillary plexus block: a meta-analysis

ObjectiveTo evaluate the value of real-time ultrasound (US) guidance for axillary brachial plexus block (AXB) through the success rate and the onset time. MethodsThe meta-analysis was carried out in the Anesthesiology Department of the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China. A literature search of Medline, EMBASE, Cochrane database from the years 2004 to 2014 was performed. The literature searches were carried out using medical subject headings and free-text word: “axilla”, “axillary”, “brachial plexus”, “ultrasonography”, “ultrasound”, “ultrasonics”. Two different reviewers carried out the search and evaluated studies independently. ResultsSeven randomized controlled trials, one cohort study and three retrospective studies were included. A total of 2042 patients were identified. 1157 patients underwent AXB using US guidance (US group) and the controlled group included 885 patients (246 patients using traditional approach (TRAD) and 639 patients using nerve stimulation (NS)). Our analysis showed that the success rate was higher in the US group compared to the controlled group (90.64% vs. 82.21%, p<0.00001). The average time to perform the block and the onset of sensory time were shorter in the US group than the controlled group. ConclusionThe present study demonstrated that the real-time ultrasound guidance for axillary brachial plexus block improves the success rate and reduce the mean time to onset of anesthesia and the time of block performance.