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36 Cards in this Set
- Front
- Back
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What is the source of ethylene glycol?
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Antifreeze*
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*Describe the characteristics of pure ethylene glycol.
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Colorless
Odorless Water-soluble Sweet tasting *** |
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How can you confirm that you completely cleaned up an ethylene glycol spill?
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Some have a fluorescent so can use a wood lamp
-may also be able to see on muzzle using this -can see fluorescent in urine bc 50% excreted unmetabolized |
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What animals are susceptible to ethylene glycol toxicity? What animals are most commonly affected?
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All are susceptible
Dogs & cats most commonly affected |
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Why is the mortality rate of ethylene glycol so high?
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Mortality high due to *difficult diagnosis and *narrow treatment time frame
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*What is the toxic dose of ethylene glycol to a 10 lb cat?
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Typical radiator solutions are 50: 50 so 1 tbsp is lethal
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Describe the metabolism to toxicity of ethylene glycol.
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Ethylene glycol--------> glycoaldehyde--------> glycolic acid---->Glyoxylic acid----> oxalic acid----> calcium oxalate---> birefringent crystals
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**What is the rate limiting step of ethylene glycol toxicity?
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Hepatic alcohol dehydrogenase
converts ethylene glycol to glycoaldehyde |
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What enzyme converts glycoaldehyde into glycolic acid during ethylene glycol metabolism?
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Aldehyde dehydrogenase
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What is the second rate limiting step of ethylene glycol toxicity?
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Lactate dehydrogenase converts glycolic acid into oxalic acid + calcium to calcium oxalate
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True or false. Ethylene glycol is directly toxic to the body.
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False, EG is no more toxic than ethanol, its the *metabolites that affect the various systems
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What are the 2 primary mechanisms of toxicity of the metabolites of ethylene glycol?
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1) Metabolic acidosis --> pH 6.9
2) Renal damage |
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Why does metabolic acidosis develop from ethylene glycol toxicity? What are the sequelae?
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Glycolic acid produced w/in 3-4 hours of ingestion--> cerebral edema & loss of consciousness
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What is the mechanism of renal damage from ethylene glycol toxicity?
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Acute renal failure due to cytotoxic & renal edema --> decreases blood flow + CaOxalate crystals blocking kidney tubules w/in 1-3 days
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What are the 4 mechanisms of toxicity of ethylene glycol?
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1) metabolic acidosis
2) renal damage 3) GI gastric irritant--> vomiting, bleeding, abdominal pain 4) Nervous system-glycoaldehyde --> glucose and serotonin metabolism depression |
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When are peak blood levels of ethylene glycol reached?
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Rapid absorption from GI tract so peak blood levels in 1-4 hours
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Most ethylene glycol is metabolized or excreted (>50% unchanged in urine) by ___-___ hrs.
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16-24 hours
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What 6 things occur during stage 1 of ethylene glycol toxicity ( 30 min to 12 h)?
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1) Ataxia & obtundness
2) Nausea & vomiting 3) PU/PD 4) Hypothermia 5) Reduced withdrawl & righting reflexes 6) Goes to seizure, coma and rarely, death |
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What 2 things occur during the second stage (12-24 hours) of ethylene glycol toxicity?
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1) Dogs may look recovered; cats remain obtund
2) Dehydration, tachycardia and tachypnea |
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What is the primary sign seen during stage 3 (12-24 hours in cats & 36-72 hrs in dogs) of ethylene glycol toxicity?
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Acute **Oliguric renal failure
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What are the 4 things that can happen during stage 3 of ethylene glycol toxicity (12-24 hrs in cats & 36-72 hrs in dogs)?
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1) Oliguric renal failure
2) Severe obtundness, lethargy--> coma 3) Anorexia, continuous vomiting, oral ulcers & hypersalivation 4) Seizure, coma and death |
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***What is the key to treating ethylene glycol toxicity?
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Difficult bc need early diagnosis (1-4 hr) paramount for successful outcome
-Key: high index of suspicion |
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How can you diagnose ethylene glycol other than suspecting exposure?
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Appropriate clinical signs/ clin path**
-chemical analysis of blood, urine, serum, plasma -woods lamp |
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**What is an in house chemical analysis test for ethylene glycol? what is the time frame to use this?
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*Kacey diagnostics KCEGT for **Parent EG
-detects >20 mg/dL **Do in first 12 hours or may get false + |
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*What's the only way to rule ethylene glycol toxicity out?
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Have to do multiple rounds of testing to rule this out
-Abnormalities are time dependent!!!! |
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What is the freezer test?
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Take stomach contents or vomitus and try to freeze it, if there's ethylene glycol in it then it won't freeze
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What clinical pathologies result from anuria due to ethylene glycol toxicity? (4)
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1) Hyperkalemia
2) Hypocalcemia (50%) 3) Hyperglycemia (50%) 4) Hyperhphosphatemia |
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***How long does it take dogs with ethylene glycol toxicity to have calcium oxalate crystals in the urine? Cats?
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Dogs: by 6 hours
Cats: by 3 hours |
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*What are the 4 components of treatment of a medical emergency with ethylene glycol toxicity?
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1) Detoxify w/ emesis or gastric lavage
-doesn't bind well to activated charcoal 2) Steps to inhibit EG metabolism 3) Steps to correct acid-base and electrolyte imbalances 4) Steps to correct fluid imbalances |
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What are 2 ways to inhibit the metabolism of ethylene glycol?
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1) 4 MP (Antizol Vet)
2) Ethanol 7% IV- less preferred bc side effects of depression & acidosis |
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What is the mechanism of action of 4 MP?
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Competitive inhibitor of alcohol dehydrogenase IV
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As long as a dog is treated with 4 MP _____ hours after ethylene glycol exposure they should live.
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8 hours
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**What are the 2 steps to correct acid-base and electrolyte imbalances caused by ethylene glycol?
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1) Bicarb if severe metabolic acidosis
2) Calcium gluconate (if severe hypocalcemia) |
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***When correcting fluid imbalances what is one thing you should make sure to check for?
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Make sure animal can make urine
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***When is the prognosis of ethylene glycol definitely poor?
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animals with oliguric renal failure
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*what is the main source of most diagnoses of ethylene glycol toxicity?
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Microscopic
-calcium oxalate/ hippurate crystals in renal tubules -degeneration/ necrosis of tubular epithelium |
