Toxins in the Garage Flashcards
What is the toxic principle found in antifreeze? What is its mechanism of action?
ethylene glycol –> sweet taste leads to frequent intoxication
metabolized by alcohol dehydrogenase to glycoaldehyde, glycolic acid, glyoxalate, and oxalic acid
What is the first phase of clinical signs associated with ethylene glycol toxicity?
30 min - 12 hours = neurological phase
- ataxia, knuckling
- “drunken behavior”
- stupor, coma
- anorexia
- vomiting
- PU/PD
What uroliths develop as a result of ethylene glycol toxicity? When do they develop?
calcium oxalate
as early as 6 hours after ingestion during the neurological phase (Stage I)
What is the second stage of ethylene glycol toxicity? What clinical signs are observed?
cardiovascular phase - 12-24 hours post ingestion
- tachypnea
- tachycardia
- often unnoticed!
When do later signs of ethylene glycol occur? What is seen?
12-72 hours post ingestion
- oliguric renal failure
- high anion gap and metabolic acidosis
- elevated osmolar gap
- hypocalcemia, hyperglycemia
How is the osmolar gap calculated?
Osm (measured) - Osm (calculated) x (2x(Na+K) + BUN/2.8 + glucose/18
When must treatment for ethylene glycol toxicity be performed? What is the preferred treatment? What is another option?
before toxic metabolites are generated (within 8 hours of ingestion)
Fomepizole (4-methylpyrazole) - competitive inhibitor of alcohol dehydrogenase –> can be used in cats, but require a higher dose
20% ethanol - competitive inhibitor of alcohol dehydrogenase, less effective than 4-MP, useful within 4-8 hours
Why does administration of 20% ethanol in treating ethylene glycol toxicosis require close monitoring?
can worsen acidosis and diuresis as well as respiratory and CNS depression
What 4 symptomatic treatments for ethylene glycol toxicosis are recommended?
- GI protectants
- IV fluids
- diuretics - mannitol, furosemide for oliguric patients
- hemodialysis or peritoneal dialysis
What is prognosis of ethylene glycol toxicosis like?
- good if therapy is started within 4-8 hours
- guarded with axotemia
- grave if oliguria/anuria is present without long-term dialysis
What toxic principles are found in common household cleaners? What occurs upon ingestion?
acids = caustic, appear immediately as burns affecting the mouth, esophagus, and stomach
alkali = corrosion, may appear within 8-12 hours
What treatment is contraindicated for ingestion of household cleaners? What is preferred?
inducing vomiting, which furthers damage to the esophagus and administering activated charcoal, which does not bind acids and alkalis
administer dilute milk or water and GI protectants for several days –> monitor for esophageal +/- gastric ulcerations –> esophageal stricture possible
What sign typically follows painting and varnishing product ingestion? What treatment is recommended? Contraindicated?
most are fairly non-toxic, but may cause mild GI upset
- remove paint from fur with paint thinners or turpentine (irritating to skin!!)
- administer milk or water
induction of vomiting –> aspiration pneumonia
What is the toxic principle of moldy garbage intoxication? What is its mechanism of action?
mold food containing penitrem A, a neurotoxin produced by Aspergillus spp.
toxin raises resting membrane potential, thereby facilitating depolarization
What clinical signs are associated with moldy garbage intoxication?
- incoordination and fine motor tremors
- panting, restlessness
- hypersalivation
- tonic spasms
- hyperthermia
- ataxia
- seizures
