title: Mulga snake (Pseudechis australis) envenoming: a spectrum of myotoxicity, anticoagulant coagulopathy, haemolysis and the role of early antivenom therapy - Australian Snakebite Project (ASP-19).
abstract: BACKGROUND
  Mulga snakes (Pseudechis australis) are venomous snakes with a wide distribution in Australia. Objective. The objective of this study was to describe mulga snake envenoming and the response of envenoming to antivenom therapy.
  
  
  METHODS
  Definite mulga bites, based on expert identification or venom-specific enzyme immunoassay, were recruited from the Australian Snakebite Project. Demographics, information about the bite, clinical effects, laboratory investigations and antivenom treatment are recorded for all patients. Blood samples are collected to measure the serum venom concentrations pre- and post-antivenom therapy using enzyme immunoassay.
  
  
  RESULTS
  There were 17 patients with definite mulga snake bites. The median age was 37 years (6-70 years); 16 were male and six were snake handlers. Thirteen patients had systemic envenoming with non-specific systemic symptoms (11), anticoagulant coagulopathy (10), myotoxicity (7) and haemolysis (6). Antivenom was given to ten patients; the median dose was one vial (range, one-three vials). Three patients had systemic hypersensitivity reactions post-antivenom. Antivenom reversed the coagulopathy in all cases. Antivenom appeared to prevent myotoxicity in three patients with high venom concentrations, given antivenom within 2 h of the bite. Median peak venom concentration in 12 envenomed patients with samples was 29 ng/mL (range, 0.6-624 ng/mL). There was a good correlation between venom concentrations and the area under the curve of the creatine kinase for patients receiving antivenom after 2 h. Higher venom concentrations were also associated with coagulopathy and haemolysis. Venom was not detected after antivenom administration except in one patient who had a venom concentration of 8.3 ng/ml after one vial of antivenom, but immediate reversal of the coagulopathy.
  
  
  CONCLUSIONS
  Mulga snake envenoming is characterised by myotoxicity, anticoagulant coagulopathy and haemolysis, and has a spectrum of toxicity that is venom dose dependant. This study supports a dose of one vial of antivenom, given as soon as a systemic envenoming is identified, rather than waiting for the development of myotoxicity.
authors.affiliation: School of Medicine Sydney, University of Notre Dame Australia, Darlinghurst, NSW, Australia.
authors.forename: C I
authors.initials: CI
authors.lastname: Johnston
authors.forename: S G A
authors.initials: SG
authors.lastname: Brown
authors.forename: M A
authors.initials: MA
authors.lastname: O'Leary
authors.forename: B J
authors.initials: BJ
authors.lastname: Currie
authors.forename: R
authors.initials: R
authors.lastname: Greenberg
authors.forename: M
authors.initials: M
authors.lastname: Taylor
authors.forename: C
authors.initials: C
authors.lastname: Barnes
authors.forename: J
authors.initials: J
authors.lastname: White
authors.forename: G K
authors.initials: GK
authors.lastname: Isbister
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000997:Antivenins / Q000627:therapeutic use*; D001315:Australia / Q000453:epidemiology; D001778:Blood Coagulation Disorders / Q000139:chemically induced* / Q000473:pathology; D002648:Child; D004546:Elapid Venoms / Q000506:poisoning*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000473:pathology; D009135:Muscular Diseases / Q000139:chemically induced* / Q000473:pathology; D009498:Neurotoxins / Q000506:poisoning*; D011446:Prospective Studies; D012909:Snake Bites / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000997:Antivenins; D004546:Elapid Venoms; D009498:Neurotoxins; C026235:Pseudechis venom