title: Venom Concentrations and Clotting Factor Levels in a Prospective Cohort of Russell's Viper Bites with Coagulopathy.
abstract: BACKGROUND
  Russell's viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell's viper envenoming.
  
  
  RESULTS
  In a prospective cohort of 146 patients with Russell's viper envenoming, we measured venom concentrations, international normalised ratio [INR], prothrombin time (PT), activated partial thromboplastin time (aPTT), coagulation factors I, II, V, VII, VIII, IX and X, and von Willebrand factor antigen. The median age was 39 y (16-82 y) and 111 were male. The median peak INR was 6.8 (interquartile range [IQR]: 3.7 to >13), associated with low fibrinogen [median,<0.01 g/L; IQR: <0.01-0.9 g/L), low factor V levels [median,<5%; IQR: <5-4%], low factor VIII levels [median,40%; IQR: 12-79%] and low factor X levels [median, 48%; IQR: 29-67%]. There were smaller reductions in factors II, IX and VII over time. All factors recovered over 48 h post-antivenom. The median INR remained >3 at 6 h post-antivenom but had reduced to <2, by 24 h. The aPTT had also returned to close to normal (<50 sec) at 24 h. Factor VII, VIII and IX levels were unusually high pre-antivenom, median peak concentrations of 393%, 307% and 468% respectively. Pre-antivenom venom concentrations and the INR (r = 0.20, p = 0.02) and aPTT (r = 0.19, p = 0.03) were correlated (non-parametric Spearman analysis).
  
  
  CONCLUSIONS
  Russell's viper coagulopathy results in prolonged aPTT, INR, low fibrinogen, factors V, VIII and X which recover over 48 h. Severity of clotting abnormalities was associated with venom concentrations.
authors: School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia; Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia; South Asian Clinical Toxicology Research Collaboration (SACTRC), Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.
authors: Geoffrey K
authors: GK
authors: Isbister
authors: School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia; South Asian Clinical Toxicology Research Collaboration (SACTRC), Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka; Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.
authors: Kalana
authors: K
authors: Maduwage
authors: Hunter Haematology Research Group, Calvary Mater Newcastle, Newcastle, New South Wales, Australia.
authors: Fiona E
authors: FE
authors: Scorgie
authors: South Asian Clinical Toxicology Research Collaboration (SACTRC), Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.
authors: Seyed
authors: S
authors: Shahmy
authors: South Asian Clinical Toxicology Research Collaboration (SACTRC), Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.
authors: Fahim
authors: F
authors: Mohamed
authors: District Hospital Hingurakgoda, Hingurakgoda, Sri Lanka.
authors: Chandana
authors: C
authors: Abeysinghe
authors: General Hospital Matara, Matara, Sri Lanka.
authors: Harendra
authors: H
authors: Karunathilake
authors: School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia; Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia.
authors: Margaret A
authors: MA
authors: O'Leary
authors: Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
authors: Christeine A
authors: CA
authors: Gnanathasan
authors: School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia; Hunter Haematology Research Group, Calvary Mater Newcastle, Newcastle, New South Wales, Australia.
authors: Lisa F
authors: LF
authors: Lincz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001778:Blood Coagulation Disorders / Q000209:etiology*; D001779:Blood Coagulation Factors / Q000378:metabolism*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D011446:Prospective Studies; D011517:Prothrombin Time; D017840:Daboia; D012909:Snake Bites / Q000097:blood* / Q000150:complications / Q000473:pathology; D014757:Viper Venoms; D055815:Young Adult
chemical_list: D001779:Blood Coagulation Factors; D014757:Viper Venoms