Post on 17-Jan-2015
description
Snakebite…Now what?
A Talk by Chris Nickson
No $
“Julius Caesar and the Crossing of the Rubicon,” Francesco Granacci, 1494
Assessment
If so, what antivenom & treatment is needed?
Is the patient envenomed?
Photo by Iguana Joe
Snake bite
Lymphatics
Non-specific Systemic Features
Specific Envenoming Syndromes
Specific Envenoming Syndromes
Venom-inducedConsumptive Coagulopathy
Anticoagulation
Neurotoxicity
Myotoxicity
Others
Does he look sick?
Photo by JD Hancock
Life Threats
HypotensionRespiratory failure
SeizureHaemorrhage
AssessmentGeographic area
Anatomic site of biteNumber of strikes
Use of PIBPre-hospital course and treatment
Previous snakebitesSystemic features
Investigations
Brown snake Pseudonaja spp
Tiger snake Notechis spp
TaipanOxyuranus spp
Death AdderAcanthophis spp
Black snake Pseudechis spp
Sea SnakesHydrophiidae
Photo by Gnangarra
InvestigationsWhole blood clotting test
Coagulation profile (INR, APTT) Fibrinogen, D-Dimer, FDPs
Full blood count Creatine kinase
Renal function and urinalysisLactate Dehydrogenase
Venom Detection Kit (VDK)
VDK does NOT tell you if a patient is
envenomed
If envenomed… VDK is an aid to
monovalent antivenom selection
First Aid
Pressure Immobilisation Bandage
PIB
Warrell DA. Treatment of bites by adders and exotic venomous snakes. BMJ. 2005 Nov 26;331(7527):1244-7.
Management
Not envenomed
Remove PIBSerial examination
Serial laboratory testsObserve for 12 hours
Envenomed
Address life threatsReplace PIB
Give AntivenomSerial assessment
Seek and treat complications
AntivenomIndications
CollapseCoagulopathy
ParalysisRhabdomyolysis
Protracted GI distress
1. Geography2. Clinical features
3. Laboratory findings
Which Antivenom to give?
http://www.kingsnake.com/aho/species/extras/budden.html
What about the snake?
How to give AntivenomResuscitation area
2 x IV lines
Give in 500 mL normal saline over 20 min
Give Monovalentif Possible
SevereAnaphylaxis
1% Monovalent
5% Polyvalent
Isbister et al. MJA 2008; 188: 437-476
Polyvalent Antivenom
Appropriate monovalent AV not available
Need >2 monovalent AVand
No SVDK or no time to wait
Premedication?Photo by Gaptone
DoesAntivenom
Work?
Isbister GK. Antivenom efficacy or effectiveness: the Australian experience. Toxicology. 2010 Feb 9;268(3):148-54.
Efficacy
Effectiveness
Inefficacious antivenom?Irreversible venom effect?Rapid onset venom effect?
Yeung JM, Little M, Murray LM, Jelinek GA, Daly FF. Antivenom dosing in 35 patients with severe brown snake (Pseudonaja) envenoming in Western Australia over 10 years. Med J Aust. 2004 Dec 6-20;181(11-12):703-5.
Isbister et al. Pathology (2006) 38(6) 568-572
Expect >8 hours until fibrinogen returns
FFP: Fuel for the Fire?
Don’t forget
ASP
THE END
http://lifeinthefastlane.com
/education/toxicology/
Photo by Peter Firminger