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Rationale: Hemidiaphragmatic paralysis (HDP) is a frequent complication of the brachial plexus block, caused by unintentional blockade of ipsilateral phrenic nerve. HDP did not rise enough alarm and attention to most anesthesiologists, because most patients with no coexisting comorbid diseases are asymptomatic and able to tolerate it. However, it may cause severe respiratory complication for patients with preexisting compromised cardiorespiratory function., Patient Concerns: A 67-year-old woman with morbidly obesity was planned to receive opening reduction and internal fixation of right humeral shaft fracture under regional anesthesia considering less respiratory and cardiovascular system interference compared with general anesthesia., Diagnoses: After ultrasound guided supraclavicular brachial plexus block, the patient developed severe hypoxia and hypercapnia.Unintentional block of phrenic nerve and diaphragm paralysis was diagnosed by diaphragm ultrasound, which was considered as the main reason of severe hypoxia., Interventions: It led to a conversion from regional anesthesia to general anesthesia with endotracheal intubation for patient's safety and smooth operation., Outcomes: The unintentional phrenic nerve block leads to a prolonged ventilation time, length of stay in intensive care unit and length of stay in hospital., Lessons: This case report highlights the risk of diaphragm paralysis in morbidly obese patients. Though new diaphragm sparing brachial plexus block (BPB) methods were developed intended to reduce the risk of HDP, no approaches could absolutely spare phrenic nerve involvement. Therefore, clinicians should always consider the risk of HDP associated with BPBs. For each individual, a detailed preoperative evaluation and sufficient preparation are paramount to avoid serious complications., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Nerve damage is consistently demonstrated after subepineural injection in animal studies, but not after purposeful injection in patients participating in clinical studies. There is a need to better visualise nerves in order to understand the structural changes that occur during subepineural injection., Methods: We scanned the brachial plexuses of three anaesthetised pigs using micro-ultrasound imaging (55-22 MHz probe), inserted 21 gauge block needles into the radial, median, and axillary nerves, and injected two 0.5 ml boluses of saline into nerves at a rate of 12 ml min -1 . Our objectives were to measure the area and diameter of nerves and fascicles, and to describe changes in nerve anatomy, comparing our findings with histology., Results: Images were acquired at 42 sites across 18 nerves in three pigs and compared dimensions (geometric ratio; 95% confidence interval; P value). As expected, the nerve cross-sectional area was greater in the proximal brachial plexus compared with the mid-plexus (2.10; 1.07-4.11; P<0.001) and the distal plexus (2.64; 1.42-4.87; P<0.001). Nerve area expanded after 0.5 ml injection (2.13; 1.48-3.08; P<0.001). Using microultrasound, subepineural injection was characterised by nerve and fascicle rotation, uniform, or localised swelling and epineural rupture. Micro-ultrasound revealed a unique pattern suggestive of subperineural injection after a median nerve injection, and good face validity with histology. Histology showed epineural trauma and inflammation to the perineurium., Conclusion: We accurately identified fascicles and real-time structural changes to peripheral nerves using micro-ultrasound. This is the first study to visualise in vivo and in real-time the motion of nerves and fascicles in response to anaesthetic needle insertion and fluid injection., (Copyright © 2021 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Brachial plexus root avulsion (BPRA) is one of the most serious injuries of the upper extremity, which requires more effective treatment. Trehalose, a natural disaccharide, has reported to has a protective effect in neurodegenerative diseases. However, the effective effects and mechanism of trehalose on BPRA are still unclear. BPRA rat model were established, and then effects of trehalose on BPRA were investigated. TBHP-treated NSC34 cells with or without trehalose treatment were used for mechanism studies by Western blotting, Immunofluorescence and Flow cytometry analysis. Trehalose elevated the survival of motor neurons in rats after BPRA, suggesting a protective role of trehlose on BPRA. Trehalose treatment in rats after BPRA enhanced the autophage and thus inhibited apoptosis compared with rats in Vehicle group. Moreover, in TBHP-treated NSC34 cells, trehalose promoted the expression of autophage-related markers (LC3 and Beclin-1), concomitant with decreased levels of apoptosis. In vitro mechanism study indicated that the regulations of trehalose on autophage and apoptosis were via the AMPK-ULK1 pathway. Trehalose protects injured MNs by enhancing autophage and inhibiting apoptosis, which demonstrating the essential role of trehalose in the prevention and treatment of BPRA., (Copyright © 2020. Published by Elsevier B.V.)

Background: The aim of study was to evaluate the efficacy of the supraclavicular brachial plexus block technique in Sapajus libidinosus., Methods: Were used eight animals, which were sedated, anesthetized, kept under hypnosis, and submitted to plexus block using a neurolocalizer. The physiological parameters, the nociception and response threshold (mA), were evaluated before and after the block. The response to electrical stimulation and cutaneous sensitivity were evaluated. The groups were compared by the Tukey or Friedman test at 5%., Results: The technique promoted blockage of the plexus, and movement of the thoracic limb in response to electrical stimulation decreased after 10 minutes. The applied milliampere increased after 5 minutes. The cutaneous sensitivity reflex decreased. The average time of return of spontaneous limb movement exceeded 50 minutes., Conclusions: The use of 5mg/kg of lidocaine 2% promoted loss of cutaneous sensitivity and limb muscle relaxation during the evaluation period., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Accumulating evidence indicates that oxidative stress and inflammation are implicated in brachial plexus avulsion (BPA). Quercetin has anti-inflammatory, anti-oxidant, anti-apoptotic, and neuroprotective properties. This study investigated the therapeutic efficacy of a temperature-sensitive poly(D,L-lactide-co-glycolide)-poly(ethylene-glycol)-poly(D,L-lactide-co-glycolide) (PLGA-PEG-PLGA) hydrogel sustained-release system of quercetin in BPA. In situ injections of the hydrogel loaded with different concentrations of quercetin were conducted in a rat model of BPA. Significantly reduced reactive oxygen species and interleukin-6 levels in the injured spinal cord 24 h post-surgery, increased number of anterior horn motor and functional neurons in the spinal cord 6 weeks post-surgery, thickened biceps muscle fibres and enlarged endplate area with clear structure, reduced demyelinated peripheral nerves, and significantly increased Terzis grooming test scores were found in the groups with 50 or 100 mg/mL quercetin-loaded hydrogels compared with the control and blank hydrogel groups. In conclusion, the temperature-sensitive quercetin loaded PLGA-PEG-PLGA hydrogel sustained-release system can alleviate oxidative damage and inflammation in the spinal cord, increase neuron survival rate, and promote nerve regeneration and motor function recovery in rats with early BPA. The findings suggest that this drug-loaded hydrogel has potential applications in the clinical treatment of BPA.

The perfusion index (PI) is an objective tool used to assess a successful nerve block. Epinephrine is a widely used adjuvant to local anesthetics, and it may affect PI values because of the vasoconstrictive property. The aim of this study was to investigate the influence of epinephrine on PI as an indicator of a successful block in ultrasound-guided supraclavicular brachial plexus block (SCBPB). In this randomized controlled trial, 82 adult patients underwent upper limb surgery under SCBPB were recruited between July 2018 and March 2019 in a single tertiary care center. Participants were randomly assigned to one of two groups: non-epinephrine group (n = 41) or epinephrine group (5 mcg ml -1 , n = 41). The primary outcome was the comparison of the "PI ratio 10," which was defined as the ratio of the PI 10 to the baseline. Receiver operating characteristic (ROC) curves were constructed to determine the accuracy of the PI in predicting the block success at each time interval. The PI ratio 10 was 2.7 (1.9-4.0) in non-epinephrine group and 3.3 (2.2-4.4) in epinephrine group (median difference: 0.4; 95% confidence interval [CI] - 1.1 to 0.2; P = 0.207). The ROC curves compared without group identification were not significantly different over time. The cut-off value for the PI and PI ratio at 5 min (PI ratio 5) were 7.7 (area under the ROC [AUROC]: 0.89, 95% CI 0.83-0.94) and 1.6 (AUROC: 0.94, 95% CI 0.90-0.98), respectively. The perineural epinephrine did not affect the PI following a SCBPB. The PI ratio 5 > 1.6 might be considered as a relatively accurate predictor of a successful SCBPB.Trial registration: This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CriS No. KCT0003006).

Ultrasound-guided costoclavicular block (CC-approach) is a recently described brachial plexus block (BPB) and an alternative approach to the supraclavicular approach (SC-approach). The relevant sonoanatomy is analogous in terms of the brachial plexus and its adjacent artery for both approaches. In the present study, we hypothesized that the two approaches will result in similar block dynamics when used the modified double-injection (MDI) technique. One hundred and twelve patients were randomly allocated to receive either a SC- or CC-approach with MDI technique. In the CC group, half the volume was injected adjacent to the medial cord of the brachial plexus, the procedure was guided by ultrasound and verified by nerve stimulator, subsequently the second half was injected close to the lateral cord. In the SC group, the MDI technique was carried out as described in our previous study. Sensory and motor blockade of all four terminal nerves were assessed with a 3-point scale. The primary outcome was the proportion of complete sensory blockade at 15 min with a predefined non-inferiority margin of -13%. The proportion of subjects at 15 min was comparable between the SC group and the CC group (91 vs 87%, absolute difference: -3%). No significant differences were found for complete motor blockade and onset times of the individual nerves within 30 min, and block-related serious adverse events (all P>0.05). We conclude that the MDI technique applied to a costoclavicular and supraclavicular block resulted in similar block dynamics. In addition, it may provide a promising alternative technique when considering the use of multipoint injection., (© 2020 The Author(s).)

Background: Existing therapies for myofascial and neuralgic forms of cervicobrachial pain may have unsatisfactory outcomes. Alternative therapies may be considered, particularly for individuals who have failed to respond. Contemporary conceptualizations of chronic pain mechanisms include the contribution of inflammatory factors; therefore, locally targeted antiinflammatory administrations may play a role in treatment of cervicobrachial pain.Alpha 2 macroglobulin (A2M) is a plasma protein that acts as a molecular trap for inflammatory factors such as tumor necrosis factor. After plasma is enriched for A2M, it may be considered as a possible injectable agent to counteract inflammation that may occur with a cervicobrachial pain syndrome., Objectives: This retrospective review evaluates patient response to the use of plasma concentrate enriched for alpha 2 macroglobulin (A2M-PPP) in treatment of neurogenic thoracic outlet syndrome (TOS) and other forms of cervical brachial syndrome., Study Design: Observational Study., Setting: Outpatient interventional neurology practice., Methods: There were 62 patients, including 46 women and 16 men ages 23-77 years. Twenty-three of these patients were diagnosed with complex regional pain syndrome (CRPS) or fibromyalgia, 18 with TOS, and 21 with musculotendinous pain (MTP). At baseline, 1 month, 3 months, and 6 months, patient status was evaluated with a Brief Pain Inventory (BPI) that included a composite pain score and a functional interference score. Patients were asked to estimate overall satisfaction with a Patient Global Impression of Change (PGIC) scale. Criterion for clinically significant improvement included >30% betterment in the BPI pain and functional interference subscales and a PGIC of > 5 at the 3-month mark., Results: Three patients, one with CRPS and 2 with TOS, complained of several days of worsened pain or dysesthesias. No serious or permanent complications were encountered. For patients with TOS at the 3-month mark, 61% achieved clinical endpoints of success compared with 35% with CRPS/fibromyalgia and 24% for patients with MTP (P < 0.05, chi-square). By 6 months, 22% of individuals in the neuropathic TOS group had > 30% improvements in pain and functional interference scores compared with 13% of the individuals in the CRPS/fibromyalgia group and 18% in the MTP group., Limitations: This article does not differentiate the added benefit of A2M-PPP from hydrodissection alone. Additionally, this article does not evaluate the actual benefit of the A2M molecule apart from other factors present in the platelet-poor concentrate such as exosomes and cytokines. With the advent of pure engineered A2M, more focused studies will be possible. Also, an independent assay was not done, and therefore we cannot be precisely sure about the exact quantity of platelets, if any, which were contained in the platelet-poor concentration., Conclusions: Results suggest that A2M-PPP, when injected into muscle, tendon, and epineurium with live ultrasound guidance, appears to be relatively safe and free of postinjection inflammatory reactions that are often seen after platelet-poor plasma injection. A2M-PPP appears to be associated more frequently with good outcomes when injected into brachial plexus targets in patients with TOS compared with outcomes observed after injection of the plexus in patients with CRPS/fibromyalgia., Key Words: Plasma concentrate enriched for alpha 2 macroglobulin, neurogenic thoracic outlet syndrome, cervical brachial syndrome.

There are two key sources of information that can be used to match forces-the centrally generated sense of effort and afferent signals from mechanical receptors located in peripheral tissues. There is currently no consensus on which source of information is more important for matching forces. The corollary discharge hypothesis argues that subjects match forces using the centrally generated sense of effort. The purpose of this study was to investigate force matching at the shoulder before and after a suprascapular nerve block. The nerve block creates a sensory and muscle force mismatch between sides when matching loads. The torque matching accuracy did not change after the nerve block was administered. Directionally, the torque error was in the direction proposed by the corollary discharge hypothesis. However, the mismatch between deltoid EMG was substantially greater compared to the changes in the torque matching error after the block. The results support that sensory information is used during force matching tasks. However, since the nerve block also created a sensory disruption between sides, it is not clear how sensory information is reweighted following the nerve block and a role for sense of effort is still implicated.

Tumour necrosis factor (TNF) and kinins have been associated with neuropathic pain-like behaviour in numerous animal models. However, the way that they interact to cause neuron sensitisation remains unclear. This study assessed the interaction of kinin receptors and TNF receptor TNFR1/p55 in mechanical hypersensitivity induced by an intraneural (i.n.) injection of rm-TNF into the lower trunk of brachial plexus in mice. The i.n. injection of rm-TNF reduced the mechanical withdrawal threshold of the right forepaw from the 3rd to the 10th day after the injection, indicating that TNF1/p55 displays a critical role in the onset of TNF-elicited neuropathic pain. The connection between TNF1/p55 and kinin B 1 and B 2 receptors (B 1 R and B 2 R) was confirmed using both knockout mice and mRNAs quantification in the injected nerve, DRG and spinal cord. The treatment with the B 2 R antagonist HOE 140 or with B 1 R antagonist des-Arg 9 -Leu 8 -BK reduced both BK- and DABK-induced hypersensitivity. The experiments using kinin receptor antagonists and CPM inhibitor (thiorphan) suggest that BK does not only activate B 2 R as an orthosteric agonist, but also seems to be converted into DABK that consequently activates B 1 R. These results indicate a connection between TNF and the kinin system, suggesting a relevant role for B 1 R and B 2 R in the process of sensitisation of the central nervous systems by the cross talk between the receptor and CPM after i.n. injection of rm-TNF.

Brachial plexus root avulsion (BPRA) results in the complete loss of motor function in the upper limb, mainly due to the death of spinal motoneurons (MNs). The survival of spinal MNs is the key to the recovery of motor function. Neuregulin-1 (Nrg1) plays fundamental roles in nervous system development and nerve repair. However, its functional role in BPRA remains unclear. On the basis of our findings that Nrg1 is down-regulated in the ventral horn in a mouse model of BPRA, Nrg1 may be associated with BPRA. Here, we investigated whether recombinant Nrg1β (rNrg1β) can enhance the survival of spinal MNs and improve functional recovery in mice following BPRA. In vitro studies on primary cultured mouse MNs showed that rNrg1β increased the survival rate in a dose-dependent manner, reaching a peak at 5 nM, which increased the survival rate and enhanced the pERK levels in MNs under H 2 O 2 -induced oxidative stress. In vivo studies revealed that rNrg1β improved the functional recovery of elbow flexion, promoted the survival of MNs, enhanced the re-innervation of biceps brachii, and decreased the muscle atrophy. These results suggest that Nrg1 may provide a potential therapeutic strategy for root avulsion., (Copyright © 2019 IBRO. Published by Elsevier Ltd. All rights reserved.)

Brachial plexus root avulsion causes severe sequelae Treatments and prognosis face many problems, including inflammatory reaction, oxidative damage, and myelin related inhibitory effect. l-Theanine has anti-inflammatory, anti-oxidative, and neuroprotective effects. NEP1-40 competitively inhibits Nogo-66 receptor (NgR1) promotes axonal regeneration. Forty-eight Sprague-Dawley rats were randomly assigned into four groups to establish an animal model of brachial plexus root avulsion. Inflammation and oxidative damage were evaluated by spectrophotometry and motor function of the upper limbs was assessed via Terzis grooming test after modeling. Immunofluorescence and hematoxylin and eosin staining were utilized to determine the content of reactive oxygen species, activation of microglial cells, neuroprotection, and nerve regeneration. Compared with the control group, the L-Theanine + NEP1-40 group had significantly decreased myeloperoxidase, malondialdehyde, interleukin-6, reactive oxygen species, and microglial cells, significantly increased score on the Terzis grooming test, increased motor neuron content, and thickened muscle fibers, increased area, and appearance of large and clear motor endplate structures. The results of this study suggest that l-Theanine combined with NEP1-40significantly promoted nerve regeneration after brachial plexus root avulsion, and may be a potential treatment for promoting nerve regeneration. Possible mechanisms underlying these results are alleviation of oxidative damage and inflammatory responses in the injured area and antagonism of myelin inhibition., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background and Objectives: For superficial surgery of anteromedial and posteromedial surfaces of the upper arm, the medial brachial cutaneous nerve (MBCN) and the intercostobrachial nerve (ICBN) must be selectively blocked, in addition to an axillary brachial plexus block. We compared efficacy of ultrasound-guided (USG) versus conventional block of the MBCN and the ICBN., Methods: Eighty-four patients, undergoing upper limb surgery, were randomized to receive either USG (n = 42) or conventional (n = 42) block of the MBCN and the ICBN with 1% mepivacaine. Sensory block was evaluated using light-touch on the upper and lower half of the anteromedial and posteromedial surfaces of the upper arm at 5, 10, 15, 20 minutes after nerve blocks. The primary outcome was the proportion of patients who had no sensation in all 4 regions innervated by the MBCN and the ICBN at 20 minutes. Secondary outcomes were onset time of complete anesthesia, volume of local anesthetic, tourniquet tolerance, and quality of ultrasound images., Results: In the USG group, 37 patients (88%) had no sensation at 20 minutes in any of the 4 areas tested versus 8 patients (19%) in the conventional group (P < 0.001). When complete anesthesia was obtained, it occurred within 10 minutes in more than 90% of patients, in both groups. Mean total volumes of local anesthetic used for blocking the MBCN and the ICBN were similar in the 2 groups. Ultrasound images were of good quality in only 20 (47.6%) of 42 patients. Forty-one patients (97.6%) who received USG block were comfortable with the tourniquet versus 16 patients (38.1%) in the conventional group (P < 0.001)., Conclusions: Ultrasound guidance improved the efficacy of the MBCN and ICBN blocks., Clinical Trial Registration: This study was registered at ClinicalTrials.gov, identifier NCT02940847.

Objectives: To evaluate the efficacy of ultrasound-guided interscalene nerve block using an ultralow volume of local anesthetic (5 mL of ropivacaine, 0.75%) for the management of post-thoracotomy shoulder girdle pain., Design: Open-cohort, prospective, single-center study., Setting: University hospital., Interventions: Patients with post-thoracotomy shoulder girdle pain (visual analog scale [VAS] ≥5) received an ultrasound-guided interscalene nerve block., Measurements and Main Results: Thirty minutes after block implementation, the VAS was used to quantify pain across the shoulder girdle. The index (I) was calculated to indicate improvement of pain as follows: [Formula: see text] Nerve bocks resulting in I ≥75% were considered excellent. Total tramadol consumption 36 hours after nerve blocks, patients' satisfaction, and complications related to the procedure also were assessed. Patients were segregated in the following 2 groups: group A, which comprised patients with pain in the shoulder area (glenohumeral and acromioclavicular joints) (n = 30), and group B, which comprised patients with pain in the scapula (n = 17). I was significantly greater in group A (88.3% ± 14%) than in group B (43.2% ± 22%). In groups A and B, 90% and 11% of patients, respectively, demonstrated excellent pain control. Total tramadol consumption in group A, 25 (0-100) mg, was significantly less that of group B, 250 (150-500) mg. Patients' satisfaction also was significantly higher in group A compared with group B. No complications were recorded., Conclusions: Ultrasound-guided interscalene nerve block can substantially alleviate post-thoracotomy pain in the shoulder but not in the scapular area., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: We report the use of a newly described regional technique, ultrasound-guided costoclavicular approach infraclavicular brachial plexus block for surgical anesthesia in two high-risk patients undergoing 2nd stage transposition of basilic vein fistula., Methods: Both patients had features of difficult airway, American Society of Anesthesiologists (ASA) physical status class III and central venous occlusive disease. The common approach, i.e., ultrasound-guided supraclavicular brachial plexus block was technically difficult with inherent risk of vascular puncture due to dilated venous collaterals at the supraclavicular area possibly compromising block quality. The risk of general anesthesia (GA) was significant as patients were morbidly obese with possible risk of obstructive sleep apnea postoperatively. As an alternative, we performed the ultrasound-guided costoclavicular approach infraclavicular brachial plexus block with 20 mL local anesthetic (LA) ropivacaine 0.5% delivered at the identified costoclavicular space using in-plane needling technique. Another 10 mL of LA was infiltrated along the subcutaneous fascia of the proximal medial aspect of arm., Results: Both surgeries of >2 hours' duration were successful, without the need of further local infiltration at surgical site or conversion to GA., Conclusions: Ultrasound-guided costoclavicular approach can be an alternative way of providing effective analgesia and safe anesthesia for vascular access surgery of the upper limb.

Objectives: To determine if the infraclavicular brachial plexus block can be applied with lower volume of local anesthetic., Design: Randomised, double-blinded clinical trial., Patients: 60 patients aged 5-15years with ASA I-II who underwent emergent or elective arm, forearm or hand operations were included in the study., Interventions: Patients were divided into two groups randomly; standard volume local anesthetic administered group (Group S, n=30) and low volume anesthetic administered group (Group L, n=30)., Measurement: Postoperative pain scores, sensory and motor block durations were noted., Main Results: Pain scores (Wong-Baker Face Scale) were evaluated and the results were detected to be similar at all times (30min, 1, 2, 4, 8, 12, 24h). Durations of motor block were 168(±16) minutes and 268(±15) minutes in Group L and Group S respectively and the difference was statistically significant (p<0.001). Durations of sensory block were 385(±26) and 402(±39) in Group L and Group S respectively and no statistically significant difference was detected (p=0.064)., Conclusion: Similar block success, postoperative sensory block durations and pain scores could be obtained during infraclavicular brachial plexus in pediatric patients with lower local anesthetic volumes., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This study evaluated electric nerve stimulation as a nerve location tool. After eliciting motor response in 43 patients undergoing shoulder surgery, the needle tip's position, distance from the closest nerve, and spread of saline were evaluated using ultrasound imaging. The needle's tip resided 1 to 4 mm from the closest nerve in 21, in direct contact with it in 7, and 6 to 18 mm away in 15 patients. In 21 patients, subsequent saline dissection did not reach the brachial plexus. Thus, the success rate of electric nerve stimulation for correct needle-nerve distance identification was 48.8%, with correct fluid spread reached in only 51.2% of patients.

Objective: To observe the anesthetic effect and safety of different doses of dexmedetomidine combined with ropivacaine for brachial plexus nerve block in children undergoing polydactyly surgery., Methods: Eighty children undergoing polydactyly surgery were randomized into 4 groups to receive brachial plexus nerve block with dexmedetomidine at 0.25, 0.50 or 0.75 µg/kg combined with 0.25% ropivacaine (0.20 mL/kg) (D1, D2, and D3 groups, respectively) or with 0.25% ropivacaine (0.20 mL/kg) only (control group). The onset time, duration of brachial plexus nerve block, awakening time, success rate, and incidence of complications were compared among the groups. Results In D2 and D3 groups, the onset time and awakening time were shorter and anesthesia lasted longer than those in the control group. The onset time and awakening time were shorter and anesthesia maintenance time was longer in D3 group than in D1 group. The success rates of brachial plexus nerve block were significantly higher in D1-3 groups than in the control group (P<0.05). Hematoma was found in one of the patients. In each of the 4 groups, laryngeal nerve block occurred in 1 child and respiratory depression in another; 2 or 3 patients had Horner syndrome, and 1 patient in D3 group experienced an episode of lowered heart beat to below 70 min -1 . All the complications were managed properly and the patients all recovered uneventfully., Conclusion: Brachial plexus nerve block with 0.5 µg/kg dexmedetomidine combined with 0.25% ropivacaine (0.20 mL/kg) is safe for effective anesthesia in children undergoing surgery for polydactyly.

Objective: To compare the motor and sensory block efficacy and duration of a modified paravertebral brachial plexus block (PBPB) after administration of lidocaine alone (LI) or combined with epinephrine (LE)., Study Design: Prospective, randomized, blinded, crossover study., Animals: A total of eight healthy female Beagle dogs., Methods: Under general anesthesia, modified PBPB was performed on the left thoracic limb using neurostimulation and/or ultrasound guidance to administer lidocaine (2 mg kg -1 ; 0.2 mL kg -1 ) either alone (treatment LI, n = 10) or with epinephrine (1:100,000; treatment LE, n = 9). Sensory block was evaluated through reaction to a painful mechanical stimulus applied at five sites on the limb. Motor block effect was evaluated according to visual gait assessments and thoracic limb vertical force measurements under dynamic and static conditions. Data were analyzed using repeated-measures generalized estimating equations. All statistical tests were performed two-sided at the α = 0.05 significance threshold., Results: The duration of sensory block did not differ significantly between treatments. Visible gait impairment was more persistent in LE than in LI (118 ± 63 minutes for LI and 163 ± 23 minutes for LE; mean ± standard deviation) (p = 0.027). At nadir value, dynamic peak vertical force was lower in LE than in LI (p = 0.007). For both dynamic and static evaluations, the nadir and the return to baseline force were delayed in LE (return to normal at 180-200 minutes) when compared with LI (130-140 minutes) (p < 0.005)., Conclusions and Clinical Relevance: The addition of epinephrine to lidocaine prolonged the duration and increased the intensity of the regional block, as verified by visual gait assessment and kinetic analysis. No significant difference was noted between treatments regarding sensory blockade. Kinetic analysis could be useful to evaluate regional anesthetic effect in dogs., (Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Background and Objectives: Dexmedetomidine has been thought to be an effective adjuvant to local anesthetics in brachial plexus blockade. We sought to clarify the uncertainty that still exists as to its true efficacy., Methods: A meta-analysis of randomized controlled trials was conducted to assess the ability of dexmedetomidine to prolong the duration and hasten the onset of motor and sensory blockade when used as an adjuvant to local anesthesia for brachial plexus blockade versus using local anesthesia alone (control). A search strategy was created to identify eligible articles in MEDLINE, EMBASE, and The Cochrane Library. The methodological quality for each included study was evaluated using the Cochrane Tool for Risk of Bias., Results: Eighteen randomized controlled trials were included in this meta-analysis (n = 1092 patients). The addition of dexmedetomidine significantly reduced sensory block time onset time by 3.19 minutes (95% confidence interval [CI], -4.60 to -1.78 minutes; I = 95%; P < 0.00001), prolonged sensory block duration by 261.41 minutes (95% CI, 145.20-377.61 minutes; I = 100%; P < 0.0001), reduced the onset of motor blockade by 2.92 minutes (95% CI, -4.37 to -1.46 minutes; I = 96%, P < 0.0001), and prolonged motor block duration by 200.90 minutes (CI, 99.24-302.56 minutes; I = 99%; P = 0.0001) as compared with control. Dexmedetomidine also significantly prolonged the duration of analgesia by 289.31 minutes (95% CI, 185.97-392.64 minutes; I = 99%; P < 0.00001). Significantly more patients experienced intraoperative bradycardia with dexmedetomidine (risk difference [RD], 0.06; 95% CI, 0.00-0.11; I = 72%; P = 0.03); however, there was no difference in the incidence of intraoperative hypotension (RD, 0.01; 95% CI, -0.02 to 0.04; I = 3%; P = 0.45). It is important to note that all studies reported that intraoperative bradycardia was either transient in nature or reversible, when needed, with the administration of intravenous atropine., Conclusions: Dexmedetomidine has the ability to hasten the onset and prolong the duration of blockade when used as an adjuvant to local anesthesia for brachial plexus blockade. Considering an analgesic effect to be either decreased pain, a longer duration of analgesic block, or decreased opioid consumption, the addition of dexmedetomidine to local anesthetics for brachial plexus blockade was found to significantly improve analgesia in all 18 included studies. However, patients receiving dexmedetomidine should be continuously monitored for the potentially harmful but reversible adverse effect of intraoperative bradycardia., Level of Evidence: Therapeutic, level I.

Shoulder surgery can result in significant postoperative pain. Interscalene brachial plexus blocks (ISBs) constitute the current criterion standard for analgesia but may be contraindicated in patients with pulmonary pathology due to the inherent risk of phrenic nerve block and symptomatic hemidiaphragmatic paralysis. Although ultrasound-guided ISB with small volumes (5 mL), dilute local anesthetic (LA) concentrations, and LA injection 4 mm lateral to the brachial plexus have been shown to reduce the risk of phrenic nerve block, no single intervention can decrease its incidence below 20%. Ultrasound-guided supraclavicular blocks with LA injection posterolateral to the brachial plexus may anesthetize the shoulder without incidental diaphragmatic dysfunction, but further confirmatory trials are required. Ultrasound-guided C7 root blocks also seem to offer an attractive, diaphragm-sparing alternative to ISB. However, additional large-scale studies are needed to confirm their efficacy and to quantify the risk of periforaminal vascular breach. Combined axillary-suprascapular nerve blocks may provide adequate postoperative analgesia for minor shoulder surgery but do not compare favorably to ISB for major surgical procedures. One intriguing solution lies in the combined use of infraclavicular brachial plexus blocks and suprascapular nerve blocks. Theoretically, the infraclavicular approach targets the posterior and lateral cords, thus anesthetizing the axillary nerve (which supplies the anterior and posterior shoulder joint), as well as the subscapular and lateral pectoral nerves (both of which supply the anterior shoulder joint), whereas the suprascapular nerve block anesthetizes the posterior shoulder. Future randomized trials are required to validate the efficacy of combined infraclavicular-suprascapular blocks for shoulder surgery.

Hemidiaphragmatic paralysis is the most common adverse effect associated with interscalene block. In most cases, it resolves with the resolution of nerve blockade with only an estimated incidence of 0.048% persisting for longer duration. Occasionally, interscalene block is also associated with recurrent laryngeal nerve block and seldom with cranial nerve paresis. We present a case of delayed onset and prolonged hemidiaphragmatic paralysis that was associated with 3 cranial nerve deficits after interscalene nerve block for shoulder surgery performed under general anesthesia in the beach chair position. Etiology is unclear, but most likely multifactorial., (Published by Elsevier Inc.)

The interscalene block (ISB) is a common adjunct to general anesthesia for total shoulder arthroplasty (TSA). The aim of the study was to report the current national demographics of the patients who are receiving ISB for TSAs. We performed a retrospective analysis of data from the National Anesthesia Clinical Outcomes Registry from 2010 to 2015. Of 28,810 cases, 42.1% received an ISB. Only 0.83% of cases received regional anesthesia as the primary anesthetic. From 2010 to 2014, there has been an increase in ISB utilization for this surgery (odds ratio, 1.21; 95% confidence interval, 1.19-1.23; P < .0001). Furthermore, we report a geographic distribution of block utilization in the United States. We have identified national patterns for the utilization of regional anesthesia for TSAs that may provide insight into future design of research studies.

Purpose: To compare the therapeutic effects on upper extremity paresthesia of intra-muscular steroid injections into the scalene muscle with those of stretching exercise only., Materials and Methods: Twenty patients with upper extremity paresthesia who met the criteria were recruited to participate in this single-blind, crossover study. Fourteen of 20 patients were female. The average age was 45.0 ± 10.5 years and duration of symptom was 12.2 ± 8.7 months. Each participant completed one injection and daily exercise program for 2 weeks. After randomization, half of all patients received ultrasound-guided injection of scalene muscles before exercise, while the other was invested for the other patients., Results: After two weeks, there was a significant decrease of the visual analog scale score of treatment effect compared with baseline in both groups (6.90 to 2.85 after injection and 5.65 to 4.05 after stretching exercise, p<0.01). However, injection resulted in greater improvements than stretching exercise (p<0.01). The number of patients with successful treatment, defined as >50% reduction in post-treatment visual analog scale, was 18 of 20 (90.0%) after injection, compared to 5 of 20 (25.0%) after stretching exercise. There were no cases of unintended brachial plexus block after injection., Conclusion: Ultrasound-guided steroid injection or stretching exercise of scalene muscles led to reduced upper extremity paresthesia in patients who present with localized tenderness in the scalene muscle without electrodiagnostic test abnormalities, although injection treatment resulted in more improvements. The results suggest that symptoms relief might result from injection into the muscle alone not related to blockade of the brachial plexus.

We systematically reviewed 25 randomised controlled trials of ultrasound-guided brachial plexus blockade that recruited 1948 participants: either one approach vs another (axillary, infraclavicular or supraclavicular); or one injection vs multiple injections. There were no differences in the rates of successful blockade with approach, relative risk (95% CI): axillary vs infraclavicular, 1.0 (1.0-1.1), p = 0.97; axillary vs supraclavicular, 1.0 (1.0-1.1), p = 0.68; and infraclavicular vs supraclavicular, 1.0 (1.0-1.1), p = 0.32. There was no difference in the rate of successful blockade with the number of injections, relative risk (95% CI) 1.0 (1.0-1.0), p = 0.69, for one vs multiple injections. The rate of procedural paraesthesia was less with one injection than multiple injections, relative risk (95% CI) 0.6 (0.4-0.9), p = 0.004., (© 2015 The Association of Anaesthetists of Great Britain and Ireland.)

Background: Common standard practice after complex arthroscopic elbow surgery includes hospital admission for 72 h. The authors hypothesized that an expedited care pathway, with 24 h of hospital admission and ambulatory brachial plexus analgesia and continuous passive motion at home, results in equivalent elbow range of motion (ROM) 2 weeks after surgery compared with standard 72-h hospital admission., Methods: A randomized, single-blinded study was conducted after obtaining approval from the research ethics board. Forty patients were randomized in a 1:1 ratio using a computer-generated list of random numbers into an expedited care pathway group (24-h admission) and a control group (72-h admission). They were treated equally aside from the predetermined hospital length of stay., Results: Patients in the control (n = 19) and expedited care pathway (n = 19) groups achieved similar elbow ROM 2 weeks (119 ± 18 degrees and 121 ± 15 degrees, P = 0.627) and 3 months (130 ± 18 vs. 130 ± 11 degrees, P = 0.897) postoperatively. The mean difference in elbow ROM at 2 weeks was 2.6 degrees (95% CI, -8.3 to 13.5). There were no differences in analgesic outcomes, physical function scores, and patient satisfaction up to 3 months postoperatively. Total hospital cost of care was 15% lower in the expedited care pathway group., Conclusion: The results suggest that an expedited care pathway with early hospital discharge followed by ambulatory brachial plexus analgesia and continuous passive motion at home is a cost-effective alternative to 72 h of hospital admission after complex arthroscopic elbow surgery.

Purpose: To investigate the effect of intraperitoneal administration of an anti-p75 neurotrophin receptor (p75NTR) antibody on reducing neuropathic pain in a rat model of brachial plexus avulsion (BPA)., Methods: We randomly assigned 40 male Wistar rats to 4 groups. In the BPA group, the C8-T1 roots were avulsed from the spinal cord at the lower trunk level, and saline was administered intraperitoneally. In the anti-p75NTR groups, 1 μL or 50 μL anti-p75NTR antibody was administered intraperitoneally after avulsion. In the sham-operated group, the lower trunk level was exposed, and saline was administered intraperitoneally. Mechanical hyperalgesia and pain-induced walking patterns were measured using von Frey filaments and CatWalk gait analysis at various time points until 15 days after administration. At 3 and 15 days after administration, sensory neurons involved in pain perception and satellite glial cells in the ipsilateral C7 dorsal root ganglia were immunolabeled with antibodies against calcitonin gene-related peptide and glial fibrillary acidic protein (GFAP), respectively. At both time points, microglial and astrocyte activation, indicative of spinal pain transmission, were immunohistochemically examined in the ipsilateral dorsal horn of the spinal cord (C7) using anti-ionized calcium-binding adaptor molecule 1 and anti-GFAP antibodies, respectively., Results: The gait pattern was significantly improved in both anti-p75NTR groups compared with the BPA group. There were significantly fewer calcitonin gene-related peptide-immunoreactive (IR) neurons, neurons encircled by GFAP-IR satellite glial cells, and GFAP-IR astrocytes in both anti-p75NTR groups compared with the BPA group at both time points. Fewer ionized calcium-binding adaptor molecule 1-IR microglia were quantified in both anti-p75NTR groups compared with the BPA group, but this was only significant at 15 days after administration., Conclusions: Systemic application of the p75NTR inhibitory antibody suppressed neuropathic pain after BPA., Clinical Relevance: p75NTR may be a potential therapeutic target for the clinical treatment of neuropathic pain in BPA injury., (Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Background and Objectives: The aim of this feasibility study was to determine the success rate (sensory and surgical) of the novel retroclavicular block and to thoroughly describe the technique. In addition, needle tip and shaft visibility, needling time, procedural discomfort, motor block success rate, patient satisfaction at 48-hour follow-up, and complications were also recorded., Methods: Fifty patients scheduled for distal upper limb surgery received an in-plane, single-shot, ultrasound-guided retroclavicular block with 40 mL of mepivacaine 1.5% with epinephrine 2.5 μg/mL. Block success was defined as a sensory score of 10/10 for the 5 nerves supplying the distal upper limb at 30 minutes. Surgical success, needle visibility, needling time, axillary artery depth, motor block rate, patient discomfort with technique, satisfaction at 48 hours, and complications were also recorded. All blocks were video-recorded and timed for further independent assessment. A chest x-ray was obtained before discharge., Results: Forty-five patients had a total sensory score of 10/10 at 30 minutes (90% success rate). Surgical success rate was 96%. Mean needling time was 3.77 minutes (25th-75th percentiles, 2.90-6.53 minutes) with a mean axillary artery depth of 3.1 ± 0.7 cm. Procedure-related discomfort (mean visual analog scale, 1.9 ± 1.2) was low. Mean 48-hour patient satisfaction rate (9.2 ± 1.1), mean needle tip (Likert scale, 3.0 ± 0.9), and shaft visibility (3.9 ± 0.9) were high. One vascular puncture and two transient paresthesias were recorded. No pneumothorax was revealed by chest x-ray., Conclusions: In this study, the novel retroclavicular block offered a quick, safe, and reliable alternative for distal arm block. Further studies, comparing this approach with the classic infraclavicular block, are required to validate its efficacy, safety, and reliability.

Purpose: We compared three methods of ultrasound-guided axillary brachial plexus block, which were single, and double perivascular (PV) infiltration techniques, and a perineural (PN) injection technique., Materials and Methods: 78 patients of American Society of Anesthesiologists physical status I-II undergoing surgery of the forearm, wrist, or hand were randomly allocated to three groups. 2% lidocaine with epinephrine 5 μg/mL was used. The PN group (n=26) received injections at the median, ulnar, and radial nerve with 8 mL for each nerve. The PV1 group (n=26) received a single injection of 24 mL at 12-o'clock position of the axillary artery. The PV2 group (n=26) received two injections of 12 mL each at 12-o'clock and 6-o'clock position. For all groups, musculocutaneous nerve was blocked separately., Results: The PN group (391.2±171.6 sec) had the longest anesthetic procedure duration than PV1 (192.8±59.0 sec) and PV2 (211.4±58.6 sec). There were no differences in onset time. The average induction time was longer in PN group (673.4±149.6 sec) than PV1 (557.6±194.9 sec) and PV2 (561.5±129.8 sec). There were no differences in the success rate (89.7% vs. 86.2% vs. 89.7%)., Conclusion: The PV injection technique consisting of a single injection in 12-o'clock position above the axillary artery in addition to a musculocutaneous nerve block is equally effective and less time consuming than the PN technique. Therefore, the PV technique is an alternative method that may be used in busy clinics or for difficult cases.

When considering brachial plexus block as a practical alternative to general anaesthesia for upper limb surgery, the time to achieve complete sensory block is a clinically important variable. In this prospective randomised double-blind controlled trial, we investigated the hypothesis that addition of hyaluronidase to ropivacaine may reduce the time to achieve complete sensory block after axillary brachial plexus block. The patients were randomly assigned into a hyaluronidase group (n = 24) and a control group (n = 24). The hyaluronidase group received ropivacaine 0.5% with 100 IU.ml(-1) of hyaluronidase, and the control group received ropivacaine alone. The primary endpoint was the time to achieve complete sensory block. The hyaluronidase group demonstrated significantly shorter mean (SD) sensory block onset time (13.8 (6.0) min) compared with the control group (22.5 (6.3) min, p < 0.0001). Addition of hyaluronidase to ropivacaine resulted in a reduction in the time needed to achieve complete sensory block., (© 2014 The Association of Anaesthetists of Great Britain and Ireland.)

Background and Objectives: This prospective, randomized trial compared ultrasound-guided targeted intracluster injection (TII) supraclavicular brachial plexus block (SCB) and infraclavicular brachial plexus block (ICB)., Methods: Sixty-four patients were randomly allocated to receive an ultrasound-guided TII SCB (n = 32) or ICB (n = 32). The local anesthetic agent (lidocaine 1.5% with epinephrine 5 μg/mL) was identical in all subjects. In the TII SCB group, half the volume (16 mL) was injected inside the largest neural cluster (confluence of trunks and divisions of the brachial plexus). Subsequently, the remaining half (16 mL) was divided into equal aliquots and injected inside every single satellite cluster. In the ICB group, the entire volume (35 mL) was injected dorsal to the axillary artery. During the performance of the block, the performance time, number of needle passes, procedural pain, and complications (vascular puncture, paresthesia) were recorded. Subsequently, a blinded observer assessed the onset time, incidence of Horner syndrome, and success rate (surgical anesthesia). The main outcome variable was the total anesthesia-related time (sum of performance and onset times)., Results: Due to a quicker onset [8.9 (5.6) vs 17.6 (5.3) minutes; P < 0.001], the total anesthesia-related time was shorter with TII SCB [18.2 (6.1) vs 22.8 (5.3) minutes; P < 0.001]. However no differences were observed between the 2 groups in terms of success rate (93.7%-96.9%), block-related pain scores, and adverse events such as vascular puncture and paresthesia. Expectedly, the ICB group required fewer needle passes (2 vs 6; P < 0.001) as well as shorter needling [4.8 (2.3) vs 9.0 (2.9) minutes; P < 0.001] and performance [5.6 (2.3) vs 9.5 (2.9) minutes; P < 0.001] times. Moreover, the ICB approach was associated with a decreased incidence of Horner syndrome (3.1% vs 53.1%; P < 0.001)., Conclusions: Ultrasound-guided TII SCB and ICB provide comparable success rates. Due to its quick onset, TII SCB results in a shorter total anesthesia-related time.

Background: Modern anesthesiology has integrated the use of ultrasonography as a tool that has displaced neurostimulation as a technique for locating peripheral nerves. The aim of this study was to determine which procedure is more effective for guiding interscalene block for total shoulder arthroplasty., Methods: We carried out a comparative, prospective non-randomized study comprised of the group guided by neurostimulation interscalene block and the group guided by ultrasound. All patients in both groups were scheduled for total shoulder arthroplasty. Latency, degree of sensory and motor block, success rate, postoperative pain intensity at 6, 12, and 24 h, patient satisfaction and complications were measured., Results: We included 110 patients, 55 per group. Patients were placed in beach chair position and the deltopectoral approach was used. There were no differences in demographic characteristics. Results for neurostimulation vs. ultrasound group: latency 19.11 ± 2.27 vs. 17.24 ± 1.42 min, p= 0.23. Block sensitivity in both groups was grade 0 motor block grade 0 in 76.4% and grade 1 in 23.6% vs. grade 0 to 100%. There was 100% success rate for both groups. Postoperative pain at 6 h was 0.13 ± 0.54 vs. 0.11 ± 0.13 p= 0.90, at 12 h 1.67 ± 1.15 vs. 1.65 ± 0.59 p= 0.89 and at 24 h 3.15 ± 1.66 vs. 2.99 ± 1.15 p= 0.78. Satisfaction 54.5% very satisfied and 45.5% satisfied 96.36% vs 3.6% very satisfied and satisfied. Complications 18.18% vs. 3.6% p= 0.023., Conclusion: Ultrasound-guided interscalene nerve block is the technique of choice in elective total shoulder arthroplasty.

The axillary approach of brachial plexus anesthesia is the most commonly used technique for forearm and hand surgery. Dynamometer is known as objective test for the clinical assessment of motor block of the nerves in brachial plexus block. However, the use of this device may not always be practical in operating room. The train-of-four (TOF) test is a non-invasive peripheral nerve stimulator that shows the level of motor block of muscle relaxants. The aim of the study is to investigate the use of TOF testing as a peripheral nerve stimulator for objective clinical evaluation of motor block at axillary brachial plexus block. 44 patients were randomized according to the development of partial or complete motor in the axillary brachial plexus block. The nerves were selectively localized by nerve stimulation and ultrasound guidance. After obtaining an appropriate peripheral motor response, predetermined volumes of bupivacaine were selectively injected to the 4 nerves. Sensory, motor block levels and TOF values were measured at 10th, 20th, 30th minutes immediately after the axillary brachial plexus block. TOF values were gradually decreased and significant difference was observed between the development of a complete and partial motor block at 30th minute. TOF values were also significantly less in patients of complete sensory block than the patients of partial sensory block at 30th minute. The use of TOF monitoring may be beneficial to assess the objective clinical effect of motor block in the patients with axillary brachial plexus nerve block.

We examined the outcomes and levels of patient satisfaction in 202 consecutive cases of ultrasound-guided supraclavicular brachial plexus block (SBPB) in upper limb surgery performed between September 2007 and March 2010. All blocks were performed by orthopaedic surgeons using ultrasound visualisation with a high-frequency linear probe. The probe was placed in the coronal-oblique plane in the supraclavicular fossa, and the puncture was 'in-plane' from lateral to medial. Most of the blocks were performed with 0.75% ropivacaine/1% lidocaine (1:1), with or without adrenaline in 1:200 000 dilution. In 201 patients (99.5%) the brachial plexus block permitted surgery without conversion to general anaesthesia. The mean procedure time for block was 3.9 min (2 to 12), the mean waiting time for surgery was 34.1 min (10 to 64), the mean surgical time was 75.2 min (6 to 232), and the mean duration of post-anaesthetic analgesia was 437 min (171 to 992). A total of 20 patients (10%) developed a transient Horner's syndrome. No nerve injury, pneumothorax, arterial puncture or systemic anaesthetic toxicity were recorded. Most patients (96.7%) were satisfied with ultrasound-guided SBPB. This study demonstrates the efficacy and safety of ultrasound-guided SBPB for orthopaedic surgery on the upper limb., (©2014 The British Editorial Society of Bone & Joint Surgery.)

Purpose: To determine the minimum volume of methylene blue (MB) to completely color the brachial plexus (BP) nerves, simulating an effective anesthetic block in cats., Methods: Fifteen adult male cat cadavers were injected through subscapular approach with volumes of 2, 3, 4, 5 and 6 ml in both forelimbs, for a total of 30 brachial plexus blocks (BPB). After infusions, the specimens were carefully dissected preserving each nervous branch. The measurement of the effective area was indicated by the impregnation of MB. Nerves were divided into four segments from the origin at the spinal level until the insertion into the thoracic limb muscles. The blocks were considered effective only when all the nerves were strongly or totally colored., Results: Volumes of 2, 3 and 4 ml were considered insufficient suggesting a failed block, however, volumes of 5 and 6 ml were associated with a successful block., Conclusions: The injection of methylene blue, in a volume of 6 ml, completely colored the brachial plexus. At volumes of 5 and 6 ml the brachial plexus blocks were considered a successful regional block, however, volumes of 2, 3 and 4 ml were considered a failed regional block.

Background and Objectives: Research suggests that the addition of dexmedetomidine to local anesthetics can prolong peripheral nerve blocks; however, clinical safety data are limited, and interscalene blocks have not been studied. The present study was designed to test the hypothesis that dexmedetomidine added to ropivacaine would safely enhance the duration of analgesia without adverse effects when compared with ropivacaine alone., Methods: We conducted a single-center, prospective, randomized, triple-blind, controlled trial of 62 patients undergoing elective shoulder surgery under general anesthesia with an interscalene block. Patients underwent ultrasound-guided interscalene blocks using either 12 mL of 0.5% ropivacaine or 0.5% ropivacaine plus 150-µg dexmedetomidine. The primary outcomes were self-reported duration of the nerve block and safety assessment (adverse effects and neurological sequelae). Data were analyzed in a blinded fashion., Results: The median duration of the nerve block was 18 hours (95% confidence interval, 18-20) in the dexmedetomidine group and 14 hours (95% confidence interval, 14-16) in the ropivacaine group (P = 0.0001). Dexmedetomidine also lowered pain scores for the first 14 hours postoperatively and significantly hastened the time to sensory (P = 0.04) and motor (P = 0.002) block onset. Dexmedetomidine lowered heart rate but blood pressures were stable. Plasma levels of ropivacaine were not different between groups, and plasma dexmedetomidine levels were relatively low. There were no adverse events or neurological sequelae., Conclusions: Dexmedetomidine added to ropivacaine for interscalene blocks increased the duration of the nerve block and improved postoperative pain. These additional efficacy and safety data should encourage further study of peripheral perineural dexmedetomidine in humans.

Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

Background: The aim of this trial was to compare the effect of concentration of bupivacaine solution on the ED₅₀ dose required for supraclavicular brachial plexus block., Methods: Nineteen ASA I, II, or III patients of either sex undergoing elective upper limb surgery under ultrasound-guided supraclavicular brachial block were recruited in this double-blind, randomized trial which followed an up-and-down sequential allocation design. The patients were randomly allocated to three groups who then received 0.25%, 0.375%, or 0.5% bupivacaine. The study design and analysis followed Dixon's small sample model using a 'nominal' sample size of six in each group. The data from previous research were used to guide the dose levels and dose intervals for the three groups., Results: The median effective volume [95% confidence interval (CI)] for 0.25%, 0.375%, and 0.5% bupivacaine for supraclavicular block was 26.8 (18.6-38.4), 18.1 (12.1-26.0), and 12.0 (8.4-17.3) ml, respectively. The ED₅₀ dose (95% CI) for 0.25%, 0.375%, and 0.5% bupivacaine was 66.9 (46.6-96.0), 68.0 (47.4-97.6), and 60.1 (41.8-86.3) mg, respectively. The difference in the ED₅₀ dose between the three concentrations was not statistically significant., Conclusions: Our study demonstrates that the ED₅₀ dose of bupivacaine for supraclavicular block is not dependent on the concentration. Lowering the concentration or the strength of the local anaesthetic leads to an increase in the volume required for successful block.

Objective: In this study we aimed to compare the echogenic needles and the nerve stimulation addition to non-echogenic needles in ultrasound guided axillary brachial plexus block for upper extremity surgery., Methods: 90 patients were enrolled to the study. The patients were allocated into three groups randomly: Group E (n=30): ultrasound guided axillary block using echogenic needle, Group N (n=30): ultrasound guided axillary block using non-echogenic needle, Group NS (n=30): ultrasound guided axillary block using non-echogenic needle with nerve stimulator assistance. Duration of block procedure, mean arterial pressure, heart rate, pulse-oximetry, onset time of sensory and motor block, duration of sensory and motor block, time to first analgesic use, total need for analgesics, postoperative pain scores, patient and surgeon satisfaction scores were recorded., Results: Duration of block procedure values were lower in group E and NS, sensory and motor block durations, were significantly lower in group N. Sensorial and motor block onset time values were found lower in group NS but higher in group N. Patient and surgeon satisfaction scores were found lower in group N., Conclusion: We conclude that ultrasound guided axillary block may be performed successfully using both echogenic needles and nerve stimulation assisted non-echogenic needles.