Peripheral Neuropathy Following Supraclavicular Brachial Plexus Block in a Patient with Recent Venomous Snake Bite: A Case Report

Peripheral Neuropathy Following Supraclavicular Brachial Plexus Block in a Patient with Recent Venomous Snake Bite: A Case Report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Peripheral Neuropathy Following Supraclavicular Brachial Plexus Block in a Patient with Recent Venomous Snake Bite: A Case Report Hongsen Xu, Hanbing Wang, Biao Sun, Jian He This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7368883/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: The brachial plexus block (BPB) is commonly utilized for upper limb surgeries; however, it carries the potential risk of nerve injury. The neurotoxic properties of snake venom may exacerbate this risk. Case Presentation: A 56-year-old male patient underwent an ultrasound- and nerve stimulator-guided supraclavicular BPB for the surgical debridement of a cobra bite wound on his left forearm. The block was administered using 25 mL of 0.4% ropivacaine. Within 48 hours postoperatively, the patient exhibited significant motor weakness and sensory loss affecting the axillary, musculocutaneous, radial, and median nerves. Electromyography confirmed the presence of axonal neuropathy, while MRI ruled out mechanical trauma. The patient experienced gradual recovery over a two-month period with the aid of corticosteroids, vitamins, and physical rehabilitation. Conclusion: Pre-existing neural injury or inflammation due to snake venom may enhance the neurotoxic effects of local anesthetics. It is advisable to exercise caution when performing regional blocks in patients who have recently been envenomated. Brachial plexus block Nerve injury Snake bite Regional anesthesia Neurotoxicity Figures Figure 1 Introduction Brachial plexus block (BPB) is commonly used for upper limb surgery, and the risk of nerve injury has been markedly reduced with the advent of ultrasound and nerve stimulation guidance[ 1 ]. However, certain pathological conditions may increase the risk of neurotoxicity. Venomous snake bites, particularly from elapid species like cobras, deliver neurotoxins that induce local nerve inflammation and axonal injury[ 2 ]. These alterations may predispose nerves to increased sensitivity to local anesthetics, thereby elevating the risk of nerve damage following regional blocks[ 3 ]. Here, we report a case of peripheral neuropathy after supraclavicular BPB in a patient recently envenomated by cobra, highlighting the need for caution in this clinical context. Case presentation A 56-year-old, 43-kg man presented 4 days after a cobra bite to the left forearm. Examination showed circumferential edema, ecchymosis over the ulnar aspect, and a cruciate incision at the fang site. Active finger motion was preserved, but the patient reported paresthesia in the median and ulnar nerve distributions. No systemic signs of envenomation were observed. Due to progressive tissue necrosis, surgical debridement and vacuum-assisted closure were scheduled. Written informed consent was obtained. In the operating theatre, standard monitors were applied, and midazolam 1 mg was given intravenously for anxiolysis. A supraclavicular brachial plexus block was then performed under dual guidance (ultrasound and nerve stimulation at 0.4 mA), using a high-frequency linear probe (6–13 MHz) and a 22-gauge, 50-mm insulated needle (Stimuplex A, B. Braun). After negative aspiration, 25 mL of 0.4% ropivacaine was injected incrementally. Complete surgical anesthesia was achieved within 15 minutes, and surgery proceeded uneventfully. Twenty-four hours after surgery, the patient reported an inability to abduct the shoulder or flex the elbow; the surgical team initially attributed this to residual block. At 48 hours, the weakness persisted. Physical examination revealed the following Medical Research Council grades: shoulder abduction and anterior flexion 3/5, elbow flexion 1/5, elbow extension 3/5, and distal upper-extremity strength 4/5. Active range of motion was shoulder flexion 85°, abduction 45°, extension 20°; elbow flexion 0° (unable to flex), extension 150°; and wrist radial flexion 7°, ulnar flexion 15°, palmar flexion 80°, dorsal extension 20°. Sensory testing demonstrated diminished pain, temperature, touch, and pressure perception in the distributions of the left axillary, musculocutaneous, radial, and median nerves compared with the contralateral side. On postoperative day 3, electrodiagnostic studies revealed low-amplitude compound muscle action potentials and prolonged distal latencies in the left radial, musculocutaneous, axillary, and lateral antebrachial cutaneous nerves, findings consistent with axonal injury. Magnetic resonance imaging of the brachial plexus was unremarkable, effectively ruling out mechanical transection (Fig. 1 A). Ultrasonography demonstrated fusiform swelling of the median nerve just proximal to the elbow, supporting a diagnosis of neuritis (Fig. 1 B). Treatment was commenced with vitamin B1 (10 mg orally three times daily), methylcobalamin (500 µg intravenously daily), oral methylprednisolone (4 mg daily), hyperbaric oxygen therapy, and an intensive physical-therapy program. At the two-month follow-up, strength had returned to Medical Research Council grades 4 + to 5 in all muscle groups, and the patient was fully independent in activities of daily living (Barthel Index 100). Discussion and Conclusions The brachial plexus (C5–T1) innervates the upper limb, and injury to its elements results in variable sensorimotor deficits. In this patient, electrophysiological abnormalities in the radial, musculocutaneous, axillary, and lateral antebrachial cutaneous nerves were consistent with a Sunderland grade I lesion [ 4 ]. High-resolution MRI—the current morphologic “gold standard” for brachial plexus lesions—showed no transection, hematoma or focal edema, effectively excluding direct mechanical injury. Consistent with this imaging finding, the supraclavicular block had been performed under dual guidance (ultrasound and 0.4-Ma nerve-stimulation) by a senior regionalist, a technique that reduces the incidence of intraneural injection and mechanical trauma to < 0.4%[ 5 ]. The needle tip was visualized continuously outside the nerve fascicles, and post-procedure ultrasound also revealed diffuse swelling of the median nerve at the axillary level, implying a more widespread process rather than a focal puncture-related lesion. Taken together, these data indicate that the observed neuropathy is unlikely to have resulted from the block needle itself. Rather than procedural trauma, the diffuse post-block neuropathy reflects a synergistic pharmacotoxic process initiated by cobra venom. Presynaptic phospholipase A₂ and cytotoxins deplete synaptic vesicles, trigger Ca²⁺-mediated mitochondrial injury, and induce axonal swelling, thereby lowering the threshold for local-anesthetic neurotoxicity [ 6 – 8 ]. These changes prime the nerve so that even sub-clinical doses of local anesthetic become neurotoxic: animal studies show that venom-exposed fibers exposed to 0.2% ropivacaine undergo accelerated Wallerian degeneration and markedly delayed functional recovery [ 9 ]. In parallel, venom-induced perineural inflammation raises endoneurial pressure, disrupts the blood–nerve barrier, and prolongs intra-fascicular drug residence[ 9 ]. Consequently, standard injectate volumes and concentrations can precipitate ischemic injury and motor-neuron death in the already compromised brachial plexus, producing the widespread deficits seen in this patient. This case highlights a critical clinical insight: the presence of subclinical or evolving nerve injury from snake venom may invalidate the usual safety profile of regional anesthesia. Anesthetists should maintain a high index of suspicion for neurotoxicity in recently envenomated patients and consider alternative analgesic approaches. If regional techniques are essential, minimizing volume and concentration of local anesthetic, using continuous real-time ultrasound imaging, and ensuring vigilant postoperative monitoring are recommended. Patient Perspective Persistent numbness and weakness after surgery frightened me, but the medical team acted swiftly, arranging EMG, rehabilitation, and medication. Thanks to their prompt care and close follow-up, my hand gradually improved; within eight weeks I could use it normally and even tie my shoelaces. I’m deeply grateful for their constant vigilance and support. Declarations Ethics approval and consent to participate: The Institutional Review Board of the First people’s Hospital of Foshan reviewed the case and determined that it did not require formal ethical approval, granting an exemption in accordance with institutional policy. Consent for publication: Written informed consent was obtained from the patient for publication of this case report and accompanying images. Availability of data and materials: All data generated or analysed during this study are included in this published article. Competing interests: The authors declare no conflicts of interest. Funding: None. Authors’ contributions: H.X. and H.W. performed the clinical work and data collection. B.S. contributed to imaging and electrodiagnostic analysis. J.H. conceptualized the report and edited the manuscript. All authors reviewed and approved the final version. References Neal JM, Barrington MJ, Brull R, Hadzic A, Hebl JR, Horlocker TT, Huntoon MA, Kopp SL, Rathmell JP, Watson JC: The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. Regional anesthesia and pain medicine 2015, 40(5):401-430. Kini RM: Excitement ahead: structure, function and mechanism of snake venom phospholipase A2 enzymes. Toxicon : official journal of the International Society on Toxinology 2003, 42(8):827-840. Hogan QH: Pathophysiology of peripheral nerve injury during regional anesthesia. Regional anesthesia and pain medicine 2008, 33(5):435-441. Sunderland S: A classification of peripheral nerve injuries producing loss of function. Brain : a journal of neurology 1951, 74(4):491-516. Feigl GC, Litz RJ, Marhofer P: Anatomy of the brachial plexus and its implications for daily clinical practice: regional anesthesia is applied anatomy. Regional anesthesia and pain medicine 2020, 45(8):620-627. Montecucco C, Gutiérrez JM, Lomonte B: Cellular pathology induced by snake venom phospholipase A2 myotoxins and neurotoxins: common aspects of their mechanisms of action. Cellular and molecular life sciences : CMLS 2008, 65(18):2897-2912. Kalita B, Utkin YN, Mukherjee AK: Current Insights in the Mechanisms of Cobra Venom Cytotoxins and Their Complexes in Inducing Toxicity: Implications in Antivenom Therapy. Toxins 2022, 14(12). Seifert SA, Armitage JO, Sanchez EE: Snake Envenomation. The New England journal of medicine 2022, 386(1):68-78. Byram SC, Bialek SE, Husak VA, Balcarcel D, Park J, Dang J, Foecking EM: Distinct neurotoxic effects of select local anesthetics on facial nerve injury and recovery. Restorative neurology and neuroscience 2020, 38(2):173-183. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7368883","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":517214273,"identity":"85c1383a-d224-4327-a24c-89e771e2e34d","order_by":0,"name":"Hongsen Xu","email":"","orcid":"","institution":"The First People's Hospital of Foshan (Foshan Hospital, Southern University of Science and Technology), Southern University of Science and 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1","display":"","copyAsset":false,"role":"figure","size":523143,"visible":true,"origin":"","legend":"\u003cp\u003eMRI of the brachial plexus and ultrasonography of the median nerve in the patient. (A) MRI image of the patient’s brachial plexus; (B) Ultrasound image of the patient’s median nerve.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7368883/v1/dbc819d7d6c7b86e3f8ea8a0.png"},{"id":92385364,"identity":"316ac77a-2515-4f51-b783-5693afdf3622","added_by":"auto","created_at":"2025-09-29 07:17:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":992849,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7368883/v1/6c2c0f0d-b278-4060-84e2-0b33f050d1a9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Peripheral Neuropathy Following Supraclavicular Brachial Plexus Block in a Patient with Recent Venomous Snake Bite: A Case Report","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBrachial plexus block (BPB) is commonly used for upper limb surgery, and the risk of nerve injury has been markedly reduced with the advent of ultrasound and nerve stimulation guidance[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. However, certain pathological conditions may increase the risk of neurotoxicity. Venomous snake bites, particularly from elapid species like cobras, deliver neurotoxins that induce local nerve inflammation and axonal injury[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. These alterations may predispose nerves to increased sensitivity to local anesthetics, thereby elevating the risk of nerve damage following regional blocks[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Here, we report a case of peripheral neuropathy after supraclavicular BPB in a patient recently envenomated by cobra, highlighting the need for caution in this clinical context.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 56-year-old, 43-kg man presented 4 days after a cobra bite to the left forearm. Examination showed circumferential edema, ecchymosis over the ulnar aspect, and a cruciate incision at the fang site. Active finger motion was preserved, but the patient reported paresthesia in the median and ulnar nerve distributions. No systemic signs of envenomation were observed.\u003c/p\u003e\u003cp\u003eDue to progressive tissue necrosis, surgical debridement and vacuum-assisted closure were scheduled. Written informed consent was obtained. In the operating theatre, standard monitors were applied, and midazolam 1 mg was given intravenously for anxiolysis. A supraclavicular brachial plexus block was then performed under dual guidance (ultrasound and nerve stimulation at 0.4 mA), using a high-frequency linear probe (6–13 MHz) and a 22-gauge, 50-mm insulated needle (Stimuplex A, B. Braun). After negative aspiration, 25 mL of 0.4% ropivacaine was injected incrementally. Complete surgical anesthesia was achieved within 15 minutes, and surgery proceeded uneventfully.\u003c/p\u003e\u003cp\u003eTwenty-four hours after surgery, the patient reported an inability to abduct the shoulder or flex the elbow; the surgical team initially attributed this to residual block. At 48 hours, the weakness persisted. Physical examination revealed the following Medical Research Council grades: shoulder abduction and anterior flexion 3/5, elbow flexion 1/5, elbow extension 3/5, and distal upper-extremity strength 4/5. Active range of motion was shoulder flexion 85°, abduction 45°, extension 20°; elbow flexion 0° (unable to flex), extension 150°; and wrist radial flexion 7°, ulnar flexion 15°, palmar flexion 80°, dorsal extension 20°. Sensory testing demonstrated diminished pain, temperature, touch, and pressure perception in the distributions of the left axillary, musculocutaneous, radial, and median nerves compared with the contralateral side.\u003c/p\u003e\u003cp\u003eOn postoperative day 3, electrodiagnostic studies revealed low-amplitude compound muscle action potentials and prolonged distal latencies in the left radial, musculocutaneous, axillary, and lateral antebrachial cutaneous nerves, findings consistent with axonal injury. Magnetic resonance imaging of the brachial plexus was unremarkable, effectively ruling out mechanical transection (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). Ultrasonography demonstrated fusiform swelling of the median nerve just proximal to the elbow, supporting a diagnosis of neuritis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eTreatment was commenced with vitamin B1 (10 mg orally three times daily), methylcobalamin (500 µg intravenously daily), oral methylprednisolone (4 mg daily), hyperbaric oxygen therapy, and an intensive physical-therapy program. At the two-month follow-up, strength had returned to Medical Research Council grades 4 + to 5 in all muscle groups, and the patient was fully independent in activities of daily living (Barthel Index 100).\u003c/p\u003e"},{"header":"Discussion and Conclusions","content":"\u003cp\u003eThe brachial plexus (C5–T1) innervates the upper limb, and injury to its elements results in variable sensorimotor deficits. In this patient, electrophysiological abnormalities in the radial, musculocutaneous, axillary, and lateral antebrachial cutaneous nerves were consistent with a Sunderland grade I lesion [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. High-resolution MRI—the current morphologic “gold standard” for brachial plexus lesions—showed no transection, hematoma or focal edema, effectively excluding direct mechanical injury. Consistent with this imaging finding, the supraclavicular block had been performed under dual guidance (ultrasound and 0.4-Ma nerve-stimulation) by a senior regionalist, a technique that reduces the incidence of intraneural injection and mechanical trauma to \u0026lt; 0.4%[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The needle tip was visualized continuously outside the nerve fascicles, and post-procedure ultrasound also revealed diffuse swelling of the median nerve at the axillary level, implying a more widespread process rather than a focal puncture-related lesion. Taken together, these data indicate that the observed neuropathy is unlikely to have resulted from the block needle itself.\u003c/p\u003e\u003cp\u003eRather than procedural trauma, the diffuse post-block neuropathy reflects a synergistic pharmacotoxic process initiated by cobra venom. Presynaptic phospholipase A₂ and cytotoxins deplete synaptic vesicles, trigger Ca²⁺-mediated mitochondrial injury, and induce axonal swelling, thereby lowering the threshold for local-anesthetic neurotoxicity [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e–\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. These changes prime the nerve so that even sub-clinical doses of local anesthetic become neurotoxic: animal studies show that venom-exposed fibers exposed to 0.2% ropivacaine undergo accelerated Wallerian degeneration and markedly delayed functional recovery [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. In parallel, venom-induced perineural inflammation raises endoneurial pressure, disrupts the blood–nerve barrier, and prolongs intra-fascicular drug residence[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Consequently, standard injectate volumes and concentrations can precipitate ischemic injury and motor-neuron death in the already compromised brachial plexus, producing the widespread deficits seen in this patient.\u003c/p\u003e\u003cp\u003eThis case highlights a critical clinical insight: the presence of subclinical or evolving nerve injury from snake venom may invalidate the usual safety profile of regional anesthesia. Anesthetists should maintain a high index of suspicion for neurotoxicity in recently envenomated patients and consider alternative analgesic approaches. If regional techniques are essential, minimizing volume and concentration of local anesthetic, using continuous real-time ultrasound imaging, and ensuring vigilant postoperative monitoring are recommended.\u003c/p\u003e"},{"header":"Patient Perspective","content":"\u003cp\u003ePersistent numbness and weakness after surgery frightened me, but the medical team acted swiftly, arranging EMG, rehabilitation, and medication. Thanks to their prompt care and close follow-up, my hand gradually improved; within eight weeks I could use it normally and even tie my shoelaces. I\u0026rsquo;m deeply grateful for their constant vigilance and support.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e The Institutional Review Board of\u0026nbsp;the First people’s Hospital of Foshan\u0026nbsp;reviewed the case and determined that it did not require formal ethical approval, granting an exemption in accordance with institutional policy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Written informed consent was obtained from the patient for publication of this case report and accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e All data generated or analysed during this study are included in this published article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e The authors declare no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e None.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eH.X. and H.W. performed the clinical work and data collection. B.S. contributed to imaging and electrodiagnostic analysis. J.H. conceptualized the report and edited the manuscript. All authors reviewed and approved the final version.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eNeal JM, Barrington MJ, Brull R, Hadzic A, Hebl JR, Horlocker TT, Huntoon MA, Kopp SL, Rathmell JP, Watson JC: The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. \u003cem\u003eRegional anesthesia and pain medicine \u003c/em\u003e2015, 40(5):401-430.\u003c/li\u003e\n\u003cli\u003eKini RM: Excitement ahead: structure, function and mechanism of snake venom phospholipase A2 enzymes. \u003cem\u003eToxicon : official journal of the International Society on Toxinology \u003c/em\u003e2003, 42(8):827-840.\u003c/li\u003e\n\u003cli\u003eHogan QH: Pathophysiology of peripheral nerve injury during regional anesthesia. \u003cem\u003eRegional anesthesia and pain medicine \u003c/em\u003e2008, 33(5):435-441.\u003c/li\u003e\n\u003cli\u003eSunderland S: A classification of peripheral nerve injuries producing loss of function. \u003cem\u003eBrain : a journal of neurology \u003c/em\u003e1951, 74(4):491-516.\u003c/li\u003e\n\u003cli\u003eFeigl GC, Litz RJ, Marhofer P: Anatomy of the brachial plexus and its implications for daily clinical practice: regional anesthesia is applied anatomy. \u003cem\u003eRegional anesthesia and pain medicine \u003c/em\u003e2020, 45(8):620-627.\u003c/li\u003e\n\u003cli\u003eMontecucco C, Guti\u0026eacute;rrez JM, Lomonte B: Cellular pathology induced by snake venom phospholipase A2 myotoxins and neurotoxins: common aspects of their mechanisms of action. \u003cem\u003eCellular and molecular life sciences : CMLS \u003c/em\u003e2008, 65(18):2897-2912.\u003c/li\u003e\n\u003cli\u003eKalita B, Utkin YN, Mukherjee AK: Current Insights in the Mechanisms of Cobra Venom Cytotoxins and Their Complexes in Inducing Toxicity: Implications in Antivenom Therapy. \u003cem\u003eToxins \u003c/em\u003e2022, 14(12).\u003c/li\u003e\n\u003cli\u003eSeifert SA, Armitage JO, Sanchez EE: Snake Envenomation. \u003cem\u003eThe New England journal of medicine \u003c/em\u003e2022, 386(1):68-78.\u003c/li\u003e\n\u003cli\u003eByram SC, Bialek SE, Husak VA, Balcarcel D, Park J, Dang J, Foecking EM: Distinct neurotoxic effects of select local anesthetics on facial nerve injury and recovery. \u003cem\u003eRestorative neurology and neuroscience \u003c/em\u003e2020, 38(2):173-183.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Brachial plexus block, Nerve injury, Snake bite, Regional anesthesia, Neurotoxicity","lastPublishedDoi":"10.21203/rs.3.rs-7368883/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7368883/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e The brachial plexus block (BPB) is commonly utilized for upper limb surgeries; however, it carries the potential risk of nerve injury. The neurotoxic properties of snake venom may exacerbate this risk.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase Presentation: \u003c/strong\u003eA 56-year-old male patient underwent an ultrasound- and nerve stimulator-guided supraclavicular BPB for the surgical debridement of a cobra bite wound on his left forearm. The block was administered using 25 mL of 0.4% ropivacaine. Within 48 hours postoperatively, the patient exhibited significant motor weakness and sensory loss affecting the axillary, musculocutaneous, radial, and median nerves. Electromyography confirmed the presence of axonal neuropathy, while MRI ruled out mechanical trauma. The patient experienced gradual recovery over a two-month period with the aid of corticosteroids, vitamins, and physical rehabilitation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003e\u0026nbsp;Pre-existing neural injury or inflammation due to snake venom may enhance the neurotoxic effects of local anesthetics. It is advisable to exercise caution when performing regional blocks in patients who have recently been envenomated.\u003c/p\u003e","manuscriptTitle":"Peripheral Neuropathy Following Supraclavicular Brachial Plexus Block in a Patient with Recent Venomous Snake Bite: A Case Report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-23 06:52:38","doi":"10.21203/rs.3.rs-7368883/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6119546c-03cb-4d2f-b1ff-b805124ab246","owner":[],"postedDate":"September 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-29T07:08:57+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-23 06:52:38","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7368883","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7368883","identity":"rs-7368883","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}