toxicology lecture 1 Flashcards
what is ocular decontamination, how do you flush it out
local irritation or permanent corneal damage - requires immediate treatment, flush medial to lateral
what is dermal deconamination
irritation, dermatitis
what can happen when GI decontamination locally
ingested toxins, gastric irritation -> induce vomiting
what can happen when GI decontamination centrally
chemoreceptor trigger zone (CRTZ) ->induce vomiting - the drug binds onto receptors and sends the message to the vomiting centre and then vomits
what 3 factors should be considered for GI Decontamination
- time of ingestion
- agents ingested
- clinical status of patients
how much time do you have to get out some ingested toxins
1-2 hour window, 17-62% if emesis is done within an hour
what are some contraindications for GI decontamination
- unconscious/depressed
- CNS stimulant
- respiratory distress
- strong acid/alkalis
- gasoline/ petroleum distillates
what are 4 ways of induction for emesis
3% hydrogen peroxide, apomorphine, xylazine, syrup of ipecac
3 things to know about 3% hydrogen peroxide induction
- can do an emesis at home - can travel to hospital if less than 1 hour
- higher than 3% HP may cause severe vomiting, mucosal irritation
- 1tbsp/20lbs or 1 ml /kg
5 things to know about apomorphine induction
- stimulates the dopamine receptors in the CRTZ
- rapid onset = first choice
- IV/SQ? tablet and conjunctival disc
- side effects include - protracted vomting, CNS depression/stimulation
* **5. does not work on cats
2 things to know about Xylazine induction
- side effects outweigh the benefits
2. don’t use on cardiac patients
2 things to know about syrup of ipecac induction
- gastric irritant and CRTZ stimulant
2. side effects include prolonged vomiting, cardiotoxic at high dose, hemorrhagic diarrhea, skeletal muscle weakness
what is gastric lavage
- used when you can’t use vomiting
- administration and evacuation of liquid through an orogastric tube
- effective within the first 1-2 hours post ingestion
- narrow margin of safety -> lethal dose LD50 = obstruction
what does activated charcoal do in GI decontamination
-binds and traps the toxin in the GI tract and exits via feces
-does not get absorbed in the GI tract
Sorbitol/ Cathartic
can you give food with activated charcoal
you can, a small amount only because the activated charcoal may bind to the food and won’t work on the animal
why would you add Carthartic (Sorbitol) with an activated charcoal?
- to accelerate the expulsion from the GI tract
- makes gastrointestinal distress when combined
which substances are not absorbed with activated charcoal
- ethanol
- fertilizer
- petroleum distillates
- heavy metal (mercury)
when should you not use an activated charcoal with a patient
vomiting, hydrocarbon, seizure, compromised airway, caustic substance
what is toxicology
the study of poison
what are the 5 most common poisons
- ethylene glycol toxicity
- rodenticide toxicity
- organophosphate toxicity
- acetaminophen toxicit
- phyrethrin toxicity
what do you monitory for ethylene glycol toxicity
fluid therapy, urine output, body weight, blood work
what is the lethal dose for ethylene glycol toxicity
- 4 ml/kg for dogs
0. 9 ml/kg for cats
what are initial clinical signs for ethylene glycol toxicity
- dose dependant
- caused by unmetabolized EG
- ~30 min after ingestion
- CNS depression, vomiting, lethargy, seizure, ataxia, PU/PD
what should you be careful about for initial clinical signs for ethylene glycol toxicity
they may disappeared, 12 hours post ingestion but they might not actually be recovered
what are the clinical signs for ethylene glycol toxicity
- acute renal failure (dogs - 24 to 72 hrs post/ cats - 12 to 24 post)
- anuria (kidneys completely shut down) 72 to 96 hours post
- depression, anorexia, vomiting, seizures, azotemia, uremia, ptyalism, oral ulcers, hyperglycemia
what may you find in the lab for testing ethylene glycol toxicity
- metabolic acidosis
- calcium oxalate crystals both monohydrate/ dihydrate crystals
- hypocalcemia
what testing can you do for ethylene glycol toxicity
EG test kit
lab test
wood’s lamp
what treatment can be done for ethylene glycol toxicity
ADH inhibition - only effective when give soon enough (6 to 8 hours post exposure)
2 things about ethanol
- has a higher affinity for ADH than EG
- side effects include CNS depression, acidosis, makes hyperosmolality worse, hypoglycemia
3 things about 4 methylphyrazole (4-mp)
- strong, competitive inhibitor of ADH
- strong affinity than ethanol
- less intensive monitoring and more predictable
what should you know about hemodialysis in regards to toxicity
remove both EG and its metabolic
what should be monitored for ethylene glycol toxicity
- fluid therapy
- urine output
- body weight
- blood work (blood glucose, electrolytes, and kidney values)
what is the prognosis of ethylene glycol toxicity
acute renal failure -> anuria, death……
what is the dosage reference for dogs for ethanol
- 20% Eth. 5.5ml/kg q4hr x 5 tx, then q6 x htx
- 30% Eth. 1.3ml/kg slow IV bolus, 0.42 ml.kg/hr for 48 hours
what is the dosage reference for cats for ethanol
20% Eth., 5ml/kg, q6hr x 5tx, then q8hr x 4tx
what is the dosage reference for dogs for 4-MP
20mg/kg IV bolus
15mg/kg at 2 hr and 24 hr
6mg/kg at 36hr
