- Title
- Investigation of the coagulant effects of Sri Lankan snake venoms and the efficacy of antivenoms
- Creator
- Maduwage, Kalana Prasad
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2016
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Coagulopathy is the commonest systemic effect of snake envenoming. Despite this there is limited information on the severity and time course of venom-induced consumption coagulopathy (VICC) and the effect of antivenom. Evidence of the efficacy and effectiveness of antivenom is vital to continue antivenom treatment for envenoming. There is increasing evidence that early administration of antivenom is essential, but there is a lack of diagnostic tests of envenoming that can be used to decide on antivenom administration. The broad aim of this project was to investigate the procoagulant effects of Sri Lankan snake venoms, and the efficacy and effectiveness of antivenoms against these effects. In addition, the study aimed to explore novel methods of testing for envenoming and for the presence of venom in blood. Snake envenoming cases in Sri Lanka were used with the collection of serial clinical and laboratory data, and blood samples from patients admitted to hospitals in Sri Lanka. Coagulopathy from hump-nosed pit viper and Russell’s viper envenoming was investigated by analyzing citrated samples from envenomed patients. Identification of the snake species was by venom specific sandwich enzyme immunoassay (EIA). Antivenom efficacy was assessed in a series of in-vitro and in-vivo animal studies. Antivenom effectiveness was assessed by undertaking two systematic reviews: Cochrane review of placebo randomized controlled trials and a systematic review of prospective and other controlled trials of antivenom for VICC. The results provide a much better description of VICC using clotting times and factor levels in both hump-nosed pit viper and Russell’s viper envenoming, showing prolonged clotting times and different factor deficiencies. Phospholipase A₂ enzyme levels were investigated as a diagnostic test for snake envenoming and will be key to improving outcomes in snake bite cases as it will allow early identification of envenomed patients so antivenom can be given when it is most effective. The efficacy of two Indian antivenoms was assessed, which showed one to be more efficacious but more importantly explored the difference between lethality studies and clinically focused in vitro studies. Two systematic reviews and antivenom for VICC revealed a lack of placebo controlled randomized trials, but that some comparative clinical trials and observational studies provide information on the effectiveness of antivenom.
- Subject
- snake envenoming; coagulopathy; antivenom; efficacy; effectiveness
- Identifier
- http://hdl.handle.net/1959.13/1314547
- Identifier
- uon:22780
- Rights
- Copyright 2016 Kalana Prasad Maduwage
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Abstract | 309 KB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Thesis | 9 MB | Adobe Acrobat PDF | View Details Download |