Toxicology 4: Case management & diagnostic veterinary toxicology Flashcards
Examination
Preform a thorough physical exam
Conduct laboratory analyses
Case history + Exam –> establish differential diagnoses
Stabilize patientEstablishing patient baseline:
collect vitals
Preserve life of patient irrespective of cause
symptomatic/supportive treatment of animal, on presentation, regarding in majority of clinical toxicology cases
-NO need to stress about antidotes unless you KNOW a toxin is the culprit
Airway/Breathing (stabilize patient)
Tachypnea
-carbon monoxide (anoxia)
-ethyl glycol (metabolic acidosis– decreased bicarb= increased pCO2-> breath off CO2)
Some chemical and irritant toxicants can:
-cause bronchospasms
-inhibit resp. centers and paralyze resp. muscles
What are the ABCDs of the poisoned patient?
Airway/Breathing
Circulation
Disability/Deficits
What are the key things to check when looking into a patients circulation?
Mucous membrane color
Blood pressure
Body temperature
Heart rate
What to focus on when looking at a patients disabilities and deficits?
Assess gross neurological deficits
Pupillary light reflex
Mental status
Ambulation
Gastrointestinal
When diagnosing and conducting laboratory analyses what should we focus on?
Clinical chemistries, CBC
-glucose
-liverenzymes
-ceratine kinase
-prothrombin and activated partial thromboplastin times (clotting times)
-creatine and BUN
-electrolytes
Decontamination of patients with toxicology emergencies is done how?
Prevent/minimize absorption of toxicant
Enhance excretion or elimination of toxicant
Remove or dilute topical irritants
Method of ocular decontamination
irritant vs corrosive
Irritant
-caution
-owner irrigates eyes with saline, eye wash, tap water
-monitor for redness, pawing eyes, swelling, lacrimation –> see DVM
Corrosive
-“danger”
-owner irrigate eyes with saline, eye wash, tap water
-antibiotic drops or ointment
-monitor for progressive signs/damage –> fluorescein stain
Methods of dermal decontamination?
What species are the most sensitive to inhalation toxicity?
BIRDS
- Examples:
oTeflon fumes
oCarbon monoxide
oHydrogen Sulfide
oNitrogen Dioxide
-Remove animal from source
-If minor irritant -> fresh air
-Humidified oxygen cage
-Supportive care (fluids, heat, etc.)
Oral exposure – how do you know when and how to decontaminate?
MOST common route of exposure
1) Emesis
2) Activated Charcoal
3) Gastric Lavage
4) Endoscopy/surgery
5) Lipid Emulsion Therapy
Ingestion of corrosive agents – what to do?
Dilution with milk or water
give a demulcent or other mucoprotective agent
-mylanta
-milk of magnesia
-kaopectate -> DOGS ONLY
- cats do NOT metabolize salicylates well
How do you induce Emesis
Apomorphine (apokyn)
Emetic activity = stimulating dopamine receptors
-Given parenterally (IM or IV) or topically in the conjunctival sac
- Triggers CRTZ = vomiting
- Preferred emetic drug for dogs
Clevor (Ropinirole)
Ophthalmic solution for use in dogs
Dopamine agonist
Drops depend on body weight
- 5.1 – 10 kg = 3 drops in one eye
- 20.1 – 35 kg = 4 drops in one eye
Apomorphine
Poor response in cats due to fewer dopamine receptors
side effects
-CNS and resp. depression, protracted vomiting
- sedative side effects reversed with naloxane, does NOT stop vomiting
- Treatment for vomiting
–cerenia
–reglan
Hydrogen Peroxide
DOGS
Xylazine & Dexmedetomidine
Emetic activity = stimulates a2-adrenergicreceptors and vomiting center
-CATS
side effects
CNS and resp. depression, bradycardia, hypotension
~these effects can be reversed with yohimbine
Drugs that DECREASE gastric emprting?
- Opioids
- Anticholinergics
- Tricyclic antidepressants
- Salicylates
Contradictions for Emesis Induction
Patient is symptomatic
laryngeal paralysis
megaesophagus
risk of aspiration pneumonia
-brachycephalic breeds
-ingestion of hydrocarbons
< 3 months old
Ingestion of corrosive agents
Patient is seizing
Rodents, horses, ruminants, rabbits
Prevention of Toxicant Absorption*
Activated charcoal
“Activated” = petroleum or vegetable origin, not mineral/animal
Adsorbs toxin/toxicant in GI tract fecal excretion
-Decreases systemic absorption
Implement immediately for maximal adsorption to poison
Effective for toxicants that undergo enterohepatic recirculation
ex. Toxiban (with or without cathartic 70% sorbitol)
Why do we NOT want Sorbitol in the charcoal (all the time)?
Cathartics
poorly absorbable salts that osmotically draw water into the gut lumen –> stimulate movement enhancing elimination of activated charcoal
T bind activated charcoal
Alcohols
Xylitol
Heavy metals
Nitrates, nitrates, chlorates
- late-stage presentation, hypernatremia, hypovolemic shick, compormised airway, GI obstruction, Risk of aspiration pneumonia, Vomiting animal, lack of borborygmi*
Gastric lavage prevention of toxicant absorption how?
May be more effective at removing gastric contents
add**
Lipid emulsion therapy
Typically soybean oil
creates a lipid “sink” in the blood –> lipid binds highly lipid soluble toxicants
GivenIV as a bolus dose at 1.5 mL/kg (20% emulsion)
Toxicology Emergencies
1) Calm down pet/livestock owner and prevent additional exposure to toxicant
2) Is it life-threatening requiring emergency care for the animal(s)?
3) Determine potential route of exposure
- Oral: Should owner induce emesis? At home/on the way to clinic?
4) Are any other animals or people at risk for exposure?
5)Ask owners questions that are “open” questions
The longer the animal is at home, the longer the animal is delayed emergency care
-bring animal in
-go do on-site visit
How do you obtain a complete case history?
Listen to the client
avoid preconceptions
Obtain medical history
Inquire about home environment
Establish a timeline of a exposure event
What are important things to keep in mind?
Keep all of your differentials open
Remain open-minded and objective
- “I think my neighbor poisoned my dog” does not mean the animal is poisoned
-Beware of “I read on the internet….”
Never tell the client “Your animal was poisoned” without conclusive evidence
Diseases progress and change in appearance with time
Most diseases encountered will have a single cause or one causative agent
Confirm active ingredient in the product for which the pet was exposed and try to get an estimate on quantity ingested
-bromethalin or brodifacoum; diphacinone or difethialone; vitamin D
-Human medications: LA, XR, ect.
-Plants
