Axillary Plexus Research Articles

Magnesium Added to Prilocaine Prolongs the Duration of Axillary Plexus Block

Magnesium Added to Prilocaine Prolongs the Duration of Axillary Plexus Block

Transarterial block as an addition to a conventional catheter technique improves the axillary block

We have had favourable experience with a triple injection technique, combining an axillary catheter technique with a transarterial axillary block. This method has been used successfully for routine surgery and re-implantation of fingers, hand or forearm. We hypothesized that with this technique, block onset time and effectiveness are better than with a conventional catheter technique, and designed a study comparing this new technique with a conventional single injection through a catheter. Fifty-one adult patients were included in a prospective study. In all patients, a short axillary plexus catheter was positioned close to the median nerve. All patients had an injection through the catheter, while 26 of the patients had an additional injection behind, and in front of, the axillary artery. Sensory and motor block were tested continuously every minute for 29 min. Block success was recorded as onset time to analgesia, anaesthesia and complete motor block in the first 29 min. At 30 and 50 min, an analgesia block score was recorded. The transarterial injection plus catheter method was more effective, with a higher success rate and faster onset, than the catheter method. Readiness for surgery with analgesia in the median, radial and ulnar nerves was achieved in the catheter group in 13 patients (52%) at a mean time of 20.8 min, and in the combined group in 21 patients (81%) at a mean time of 13.3 min (P<0.05, P<0.05). At 50 min the situation was 17 (68%) and 24 (92%), respectively (P<0.05). The combined triple injection is faster and more effective than the catheter method alone.

Ultraschallgestützte Blockade des axillären Plexus brachialis in der Handchirurgie

Blockade of the axillary plexus brachialis is an integral part of the anesthetic-specific procedures in the field of hand surgery. Less side-effects with high success rates are demanded of the surgeons and required by the patients. Normally, blockade of the axillary plexus brachialis is performed by using nerve stimulation. An alternative technique described here as a retrospective study uses ultrasound for detection of the nerves. At the level of axilla, anatomical structures (axillary vein and artery, triceps/coracobrachialis muscles, ulnar/radial/median nerves) were visualized by ultrasound (linear scanner, 10-MHz transducer). At this position, a puncture needle was inserted into the nerves and local anesthetics were injected (50 ml prilocaine 1 % or 40 prilocaine 1 % and 20 ropivacaine 0.5 %). Parameters like onset time of blockade (min), complete block (yes/no) and possible complications were documented. In 30 months 221 ultrasound-guided blocks of axillary plexus brachialis were performed by eight anesthetists with different levels of training. In 96.8 % of the documented cases blockade was complete and did not require any supplementation. Only in seven cases was a conversion of the anesthetic technique performed. Adverse effects like toxic-allergic reactions or nerve damage caused by the punctures were not documented in any case. The average time to onset of the blockade was 2.2 minutes. Ultrasound-guided blockade of the axillary plexus brachialis represents an alternative to procedures using nerve stimulation, even in patients with anatomic abnormalities. The described method proved to be effective, especially in the field of hand surgery.

Blood Collection

AbstractBlood is most frequently sampled for evaluation of serum antibodies or analysis of surface markers on peripheral blood cells. The protocols offered in this unit describe collection of blood from the orbital sinus or plexus of the mouse, rat, or hamster. With appropriate techniques, small amounts of blood can be obtained with little ill effect on the animal. Collection from the auricular vein or artery of the rabbit is also relatively unstressful to the animal. Bleeding procedures that should be performed on the anesthetized animal include collection from the mouse axillary plexus, cardiac puncture of the mouse, rat, hamster, or rabbit, and collection from the hamster abdominal aorta or vena cava.

Axillary plexus block according to Weber is more effective than Büttnerʼs method in supine position

Axillary plexus block according to Weber is more effective than Büttnerʼs method in supine position

Efficacy of vertical infraclavicular plexus block vs. modified axillary plexus block: a prospective, randomized, observer‐blinded study

Despite containing severe risks, infraclavicular approaches to the brachial plexus gained increasing popularity. Likewise, the vertical infraclavicular plexus block improved anesthesia compared to the standard axillary approach but contains the risk of pneumothorax. Therefore we modified the standard axillary technique by inserting a proximal directed catheter, referred to as a high axillary plexus block. We prospectively compared quality and onset of neural blockade after vertical infraclavicular plexus block (VIP) and high axillary plexus block (HAP) in two randomized groups (30 patients in each). In group VIP the insulated needle was inserted midway between the ventral process of the acromion and the jugular notch. In group HAP, first an axillary needle was placed. Through this a stimulating catheter was inserted in a proximal direction (10-15 cm); correct placement was confirmed by nerve stimulation. All patients received 40 ml ropivacaine 0.75% (300 mg). Discriminating between analgesia and anesthesia, a blinded observer assessed progression of neural blockade every 5 min for 60 min by pin prick. Incomplete blocks were supplemented 60 min after initial injection. All patients in both groups demonstrated sufficient surgical anesthesia. No patient needed systemic supplementation or general anesthesia. However, vertical infraclavicular plexus block indicated superior anesthesia compared to high axillary plexus block, regarding musculocutaneous, axillary and radial nerve, which were completely blocked with a higher success rate and in a shorter time interval (P < 0.05). While both techniques provide sufficient surgical anesthesia, vertical infraclavicular plexus block demonstrated a partially higher success rate and a faster onset than high axillary plexus block.

Anaesthesia of the axillary plexus induces rapid improvement of sensory function in the contralateral hand: An effect of interhemispheric plasticity

Acute improvement of sensory functions in the contralateral hand during experimental, tourniquet-induced anaesthesia has been described. Tourniquet compression over an extended time period, however, may be painful - which may influence the result. To study the effects of deafferentation of the upper extremity with the pain factor eliminated, we investigated 100 patients with anaesthetised axillary plexus for perception of touch and tactile discrimination in the contralateral (unanaesthetised) hand. Anaesthesia induced a rapid, significant, improvement in tactile discrimination in the contralateral hand, compared with before anaesthesia, measured as two-point discrimination (p=0.0001), and perception of touch, measured with Semmes-Weinstein monofilament (p=0.0005). The improvement lasted as long as the arm was anaesthetised. Understanding the mechanisms of brain plasticity, including interhemispheric plasticity, is essential for designing appropriate strategies for upregulation and downregulation of cortical reorganisational changes to promote sensory relearning after nerve injury.

Ultrasound-Guided Rescue Blocks: A Description Of A Technique For The Median And Ulnar Nerves

Strategies for supplementing incomplete brachial plexus blocks are important skills for the regional anaesthesiologist. We report two patients who presented for hand surgery and had incomplete brachial plexus blockades. High resolution ultrasound was utilized to localize the median and ulnar nerves in the forearm. Patient 1 had sparing in the median nerve distribution following an infraclavicular plexus block. The median nerve was localized 6 cm proximal to the wrist and anesthetized using 5 ml of 1.5% lidocaine. Patient 2 sustained ulnar nerve sparing following an axillary plexus block. The ulnar nerve was visualized 4 cm proximal to the wrist and anesthetized with 5 ml of 1.5% lidocaine. Both patients developed a surgical anesthetic with the supplemental block and surgery was completed uneventfully.

Percutaneous electrode guidance using the insulated needle for prelocation of peripheral nerves during axillary plexus blocks

Background and objectives Short reports have noted that percutaneous prelocation is helpful in determining the anatomic course of a peripheral nerve, and, thereby, may serve as a guide for block needle insertion. We prospectively studied percutaneous electrode guidance to assist axillary brachial plexus blocks. Methods In 131 consecutive patients, the tip of an insulated needle emitting 5 mA was placed on the skin above and below the axillary artery to obtain a hand motor response characteristic of the median, ulnar, and radial nerves in succession. The current was reduced until all movement had ceased. The needle was then inserted toward the nerve to be blocked, decreasing the intensity from 2 mA to 0.5 mA, so that the same selected motor response was still obtained. The length of the needle inserted was noted, and 1.5% lidocaine was injected. Pain verbal analogic score (VAS) values were noted during both procedures. Complete sensory blockade was evaluated at 30 min. Results Rates of successful percutaneous electrode guidance were 94.6% for the median nerve, 89.4% for the radial nerve, 88.5% for the ulnar nerve, and 85.5% for all 3 nerves together. A significant correlation was found between the lowest percutaneous current applied and the depth of the nerve stimulated at 0.5 mA. Pain VAS values were significantly lower during percutaneous stimulation than during needle insertion ( P < .05). Sensory block for all 3 nerves was noted in 92% of patients. Conclusions Percutaneous electrode guidance using the insulated needle enabled clinicians to locate the terminal branches of the plexus in the axilla and appreciate their depth. This method could, therefore, minimize patient discomfort and perhaps the risk of nerve trauma.

Percutaneous Electrode Guidance Using the Insulated Needle for Prelocation of Peripheral Nerves During Axillary Plexus Blocks

Percutaneous Electrode Guidance Using the Insulated Needle for Prelocation of Peripheral Nerves During Axillary Plexus Blocks

Perioperative intravenous adenosine infusion to extend postoperative analgesia in brachial plexus block

Background and objective: Adenosine infusions have been shown to reduce requirements of anaesthetics, to decrease the need for postoperative analgesics and to attenuate hyperaesthesia related to neuropathic pain. We decided to investigate the effects, beneficial or otherwise, of an adenosine infusion administered during surgery. A brachial plexus block was used to produce anaesthesia for the surgery. Methods: Sixty adults undergoing upper extremity surgery were included in the study. Brachial plexus block was performed via an axillary approach with lidocaine 1.25% and epinephrine 1/200 000 (40 mL). Patients were randomly assigned to two groups. During surgery, saline (control) or adenosine 80 μg kg min was infused intravenously in a double-blind fashion for 1 h. Visual analogue scores every 4 h, analgesic consumption, time to first spontaneous pain sensation, time to first rescue analgesic and adverse effects were noted during the first 24 h. Results: Vital signs were stable in both groups throughout surgery. During the adenosine infusion, one patient fainted while another complained of palpitations and tightness of the chest; both patients were excluded from further analyses. The time to first sensation of pain was significantly longer in the adenosine group compared to the control group (438 ± 387 vs. 290 ± 227 min, P = 0.02). The time to first rescue analgesic, the visual analogue scale scores and analgesic consumption in the postoperative period were similar. Conclusions: In patients undergoing surgery with an axillary plexus block, a perioperative adenosine infusion prolongs the duration of postoperative analgesia to some extent. However, the time to first rescue analgesic, total analgesic requirements and pain scores were unchanged; the risk of potentially serious adverse effects is high. This therapy cannot be recommended.

Comparison of three different volumes of mepivacaine in axillary plexus block using multiple nerve stimulation

The multiple injection technique for axillary block, in which the four distal nerves of the plexus are located by a nerve stimulator and separately injected, has been shown to provide a high success rate and a short onset time. This randomized double-blind study was conducted to compare the effectiveness of three different volumes of mepivacaine 10 mg x ml(-1) in patients undergoing elective distal upper limb surgery under axillary brachial plexus block with the four-nerve approach. The number of complete sensory blocks was the primary efficacy variable. A total of 114 adult patients were randomly allocated to receive 36 (n=38), 28 (n=38), and 20 ml (n=38) of mepivacaine 10 mg x ml(-1). In each group, volumes were equally distributed in the four nerve territories. In all patients, performance time, latency time, block characteristics, need of supplementary blocks, tourniquet tolerance, duration of analgesia, and complications were recorded. Complete sensory block was obtained in 97% of patients receiving a volume of 36 ml, 97% of those receiving 28 ml, and 94% of those receiving 20 ml. One patient in the group of 28 ml and five patients in the group of 20 ml experienced pain on inflation of the tourniquet. Two months after surgery, no case of postoperative neurological dysfunction was observed. The three volumes (38, 28, and 20 ml) of mepivacaine 10 mg x ml(-1) ensured a similar and high percentage of complete sensory blocks in axillary brachial plexus anaesthesia with nerve stimulation involving the location of four motor responses.

Addition of fentanyl to mepivacaine does not affect the duration of brachial plexus block

Abstract Objectives : Numerous studies dealing with the effects of the addition of opioids to a local anesthetic (LA) in peripheral nerve block have been published, but results are conflicting. The present study was aimed at studying the question of whether fentanyl addition to mepivacaine could improve intra- and postoperative conditions of an axillary plexus block. Methods : After institutional approval and informed consent, 51 patients (ASA I and II) undergoing plexus anesthesia for forearm and hand surgery were included into the study. Patients were randomly assigned to one of three groups: group A (50 ml mepivacaine, 15 mg ml −1 , with 4 ml saline for nerve block and 4 ml normal saline (NS) subcutaneously), group B (50 ml mepivacaine, 15 mg ml −1 , with 100 μg fentanyl in 4 ml NS for nerve block, and 4 ml NS subcutaneously), or group C (50 ml mepivacaine, 15 mg ml −1 , with 4 ml NS for nerve block and 100 μg fentanyl in 4 ml saline subcutaneously). Visual analogue score (VAS), sensory block, motor block and hemodynamics were recorded prior to and 5, 10, 30 and 60 min and 2, 3, 4, 12 and 24 h after induction of the block. Results : There were no differences in VAS scores, time to administration of the first postoperative dose of an analgesic, or the total dose of analgesic given postop. No differences with respect to the intensity of sensory block and motor block or time to onset of block were observed. Conclusions : Addition of 100 μg fentanyl to mepivacaine, 15 mg ml −1 , does not affect the quality of anesthesia of brachial plexus block.

Adjonction de la néostigmine au cours du bloc plexique par voie axillaire : quel bénéfice ?

Introduction. – Recent study showed that neostigmine (500 μg) by intra-articular produces postoperative analgesia without adverse effect. The author’s goal was to determine whether 500 μg of neostigmine added to bupivacaine in axillary plexus block could prolonged postoperative analgesia without increasing the incidence of side effects. Methods. – Ninety patients scheduled for orthopedic or plastic surgery with axillary plexus block were randomyly assigned to one of 3 groups : group 1 (TGr n = 30) received saline solution (1 ml) in the axillary plexus, group 2 (NAGr n = 30) received 500 μg (1 ml) neostigmine in the axillary plexus and group 3.500 μg neostigmine subcutaneously (NSGr n = 30). We evaluated visual analog pain scores (VAS), the consumption of the ketoprofene, nausea and vomiting incidence during the first 24 h. ANOVA, Kruskall Wallis and Fisher tests were used for statistical analysis. A p value of <0.05 was considered significant. Results. – The VAS score was lower in NAGr (21 ± 18) vs NSGr (31 ± 14) and control group TGr (45 ± 2) ( p < 0.05). The consumption of the ketoprofene is 127 ± 65 mg in NAGr vs 150 ± 53 mg in NSGr and 200 ± 50 mg in group TGr ( p = 0.02). Incidence of nausea and vomiting was 3.5% in NAGr vs 6.8% in NSGr and 0% for TGr. Conclusion. – Neostigmine combined to a mixture of lidocaine and bupivacaine prolongs postoperative analgesia after axillary plexus block.

The arteriovenous fistula.

The ground-breaking article by Brescia and Cimino in 1966 ([1][1]) revolutionized the creation of the vascular access, and the Cimino fistula was soon used in almost all dialysis patients. Unfortunately, subsequent wide-spread use of PTFE grafts instead of AV fistulae occurred because of the ease of

Influence of nervous blockade on insulin-mediated glucose uptake in the human forearm

This study was undertaken to investigate if a nonpharmacologic increase in forearm blood flow (FBF) could increase forearm glucose uptake (FGU) during hyperinsulinemia. In 10 young volunteers, FBF and the arterial-venous glucose difference were measured in both arms during a 2-hour euglycemic hyperinsulinemic clamp procedure when 1 of the arms was subjected to axillary plexus nervous blockade with local anesthesia. FBF was measured in both arms by venous occlusion plethysmography. Nervous blockade, increasing FBF by more than 3-fold, did not improve insulin-mediated FGU. On the contrary, a tendency towards a reduced FGU compared with the control arm was seen (P =.07). Furthermore, while insulin increased FBF to a similar degree in both arms (+ 3.0 and 4.4 mL/min/100 mL tissue, P <.01 for both arms), nervous blockade abolished the rapid increase in glucose extraction seen in the control arm when insulin infusion was initiated. The present study showed that an increase in FBF induced by nervous blockade did not increase insulin-mediated FGU. On the contrary, a tendency towards a reduction was seen. Furthermore, insulin induced vasodilation in the blocked arm, but delayed the ability of insulin to promote glucose extraction, suggesting that the well-documented increase in skeletal muscle sympathetic nerve activity seen during acute hyperinsulinemia has metabolic rather than hemodynamic consequences. Copyright 2003 Elsevier, Inc. All rights reserved.

Increasing the injection volume by dilution improves the onset of motor blockade, but not sensory blockade of ropivacaine for brachial plexus block

Background and objective: Ropivacaine used for axillary plexus block provides effective motor and sensory blockade. Varying clinical dosage recommendations exist. Increasing the dosage by increasing the concentration showed no improvement in onset. We compared the behaviour of a constant dose of ropivacaine 150 mg diluted in a 30, 40 or 60 mL injection volume for axillary (brachial) plexus block. Methods: A prospective, randomized, observer-blinded study on patients undergoing elective hand surgery was conducted in a community hospital. Three groups of patients with a constant dose of ropivacaine 150 mg, diluted in 30, 40 or 60 mL NaCl 0.9%, for axillary plexus blockade were compared for onset times of motor and sensory block onset by assessing muscle strength, two-point discrimination and constant-touch sensation. Results: Increasing the injection volume of ropivacaine 150 mg to 60 mL led to a faster onset of motor block, but not of sensory block, in axillary plexus block, compared with 30 or 40 mL volumes of injection. Conclusions: The data show that the onset of motor, but not of sensory block, is accelerated by increasing the injection volume to 60 mL using ropivacaine 150 mg for axillary plexus block. This may be useful for a more rapid determination of whether the brachial plexus block is effective. However, when performing surgery in the area of the block, sensory block onset seems more important.

Effects of blockade of alpha- and beta-adrenoceptors and neuropeptide Y(1) receptors, as well as brachial plexus blockade, on endothelium-dependent vasodilation in the human forearm.

1. The aim of the present study was to investigate the effects of alpha-adrenoceptor blockade (phentolamine), beta-adrenoceptor blockade (propranolol), neuropeptide Y(1) receptor blockade and neurogenic blockade (brachial plexus) on endothelium-dependent vasodilation (EDV) in the human forearm. 2. Forty-four young healthy volunteers underwent forearm blood flow (FBF) measurements, using venous occlusion plethysmography, during local intra-arterial infusions of methacholine (MCh; inducing EDV) and sodium nitroprusside (SNP; inducing endothelium-independent vasodilation (EIDV)). These measurements were undertaken at baseline and were repeated with either concomitant local intra-arterial infusion of phentolamine (n = 8), propranolol (n = 7) or saline (n = 6) in the forearm, neuropeptide Y(1) receptor blockade (n = 12) given i.v. or during axillary plexus blockade (n = 11). 3. Both alpha-adrenoceptor blockade and neurogenic blockade induced an upward shift in the dose-response curve for both EDV and EIDV. beta-Adrenoceptor blockade did not change resting FBF or EIDV, but induced a significant decrease in EDV (P = 0.015). Neuropeptide Y(1) receptor blocker induced no significant changes in resting FBF, EDV and EIDV and neither did saline. No changes in blood pressure or heart rate were induced by any of the blockades. 4. Whereas beta-adrenoceptor blockade impaired EDV, alpha-adrenoceptor blockade and neurogenic blockade caused a general vasodilation that was not endothelium dependent. Neuropeptide Y does not seem to influence blood flow in the resting forearm.

Some historical perspectives on axillary plexus block

Some historical perspectives on axillary plexus block

Pharmacokinetics and efficacy of 40 ml ropivacaine 7.5 mg/ml (300 mg), for axillary brachial plexus block--an open pilot study.

In this study, the pharmacokinetics, tolerability and efficacy of 40 ml of ropivacaine 7.5 mg/ml (300 mg) for axillary brachial plexus block were investigated. With institutional review board approval, 10 patients presenting for surgery of the upper limb were enrolled in this open study. The axillary plexus was identified with a nerve stimulator and the study drug was injected into the neurovascular sheath. Fifteen venous blood samples were obtained from each patient for pharmacokinetic measurements over a 24-h period. All blocks were sufficient for surgery after 45 min without any need for supplemental analgesia or general anesthesia. The mean (SD) peak plasma concentration was 2.3 (0.8) mg/l at median tmax 54 min (range 16-92 min). The mean (SD) maximum free plasma concentration was calculated to be 0.12 (0.06) mg/l (range 0.07-0.29 mg/l). The t 1/2 was about 6 h. There were no clinical signs or symptoms of central nervous system and/or cardiac toxicity in any patient. Ropivacaine 7.5 mg/ml, used in a dose of 300 mg, was effective and well tolerated for axillary brachial plexus block.