title: Neuromuscular Effects of Common Krait (Bungarus caeruleus) Envenoming in Sri Lanka.
abstract: OBJECTIVE
  We aimed to investigate neurophysiological and clinical effects of common krait envenoming, including the time course and treatment response.
  
  
  METHODS
  Patients with definite common krait (Bungarus caeruleus) bites were recruited from a Sri Lankan hospital. All patients had serial neurological examinations and stimulated concentric needle single-fibre electromyography (sfEMG) of orbicularis oculi in hospital at 6 wk and 6-9 mth post-bite.
  
  
  RESULTS
  There were 33 patients enrolled (median age 35 y; 24 males). Eight did not develop neurotoxicity and had normal sfEMG. Eight had mild neurotoxicity with ptosis, normal sfEMG; six received antivenom and all recovered within 20-32 h. Seventeen patients developed severe neurotoxicity with rapidly descending paralysis, from ptosis to complete ophthalmoplegia, facial, bulbar and neck weakness. All 17 received Indian polyvalent antivenom a median 3.5 h post-bite (2.8-7.2 h), which cleared unbound venom from blood. Despite this, the paralysis worsened requiring intubation and ventilation within 7 h post-bite. sfEMG showed markedly increased jitter and neuromuscular blocks within 12 h. sfEMG abnormalities gradually improved over 24 h, corresponding with clinical recovery. Muscle recovery occurred in ascending order. Myotoxicity was not evident, clinically or biochemically, in any of the patients. Patients were extubated a median 96 h post-bite (54-216 h). On discharge, median 8 days (4-12 days) post-bite, patients were clinically normal but had mild sfEMG abnormalities which persisted at 6 wk post-bite. There were no clinical or neurophysiological abnormalities at 6-9 mth.
  
  
  CONCLUSIONS
  Common krait envenoming causes rapid onset severe neuromuscular paralysis which takes days to recover clinically consistent with sfEMG. Subclinical neuromuscular dysfunction lasts weeks but was not permanent. Antivenom effectively cleared venom but did not prevent worsening or reverse neuromuscular paralysis.
authors.affiliation: Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Victoria, Australia.|Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.|South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka.
authors.forename: Anjana
authors.initials: A
authors.lastname: Silva
authors.affiliation: South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka.|Clinical Toxicology Research Group, University of Newcastle, New South Wales, Australia.
authors.forename: Kalana
authors.initials: K
authors.lastname: Maduwage
authors.affiliation: South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka.
authors.forename: Michael
authors.initials: M
authors.lastname: Sedgwick
authors.affiliation: Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
authors.forename: Senaka
authors.initials: S
authors.lastname: Pilapitiya
authors.affiliation: Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
authors.forename: Prasanna
authors.initials: P
authors.lastname: Weerawansa
authors.affiliation: Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
authors.forename: Niroshana J
authors.initials: NJ
authors.lastname: Dahanayaka
authors.affiliation: South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka.|Clinical Pharmacology, University of Sydney, Sydney, Australia.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Buckley
authors.affiliation: Clinical Toxicology Research Group, University of Newcastle, New South Wales, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Johnston
authors.affiliation: Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
authors.forename: Sisira
authors.initials: S
authors.lastname: Siribaddana
authors.affiliation: South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka.|Clinical Toxicology Research Group, University of Newcastle, New South Wales, Australia.
authors.forename: Geoffrey K
authors.initials: GK
authors.lastname: Isbister
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000997:Antivenins / Q000627:therapeutic use; D002038:Bungarotoxins / Q000633:toxicity*; D017838:Bungarus; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009420:Nervous System / Q000187:drug effects*; D009465:Neuromuscular Agents; D010243:Paralysis / Q000473:pathology*; D012909:Snake Bites / Q000473:pathology*; D013188:Sri Lanka; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000997:Antivenins; D002038:Bungarotoxins; D009465:Neuromuscular Agents
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