Diagnosis and Treatment of Toxicity Flashcards
5 things to look for and treat immediately
- heart rate
- respiratory rate
- temperature
- seizure and brain function
- hemorrhage
respiratory maintenance
- unconscious, paralyzed, and severe respiratory distress patients are candidates for intubation
-
ventilation may be needed if there is:
- hypoventilation and hypercapnia
- metabolic acidosis
- hypoxia (treat with 40% oxygen)
control CNS activity
-
control hyperactivity
- diazepam, phenobarb, methocarbamol
-
control depression
- analeptics, doxapram
control CV function
-
tachycardia and arrythmias
- correct acid/base, electrolyte or fluid disorders
- lidocaine, propanolol
-
hypertension
- nitroprusside, hydralazine
- fluid therapy-balanced electrolyte solution for shock and dehydration, monitor urine output, inotropic drugs like dobutamine
stabilize the patient
- priority in animals presenting with severe clinical signs (hyper/hypothermia)
- obtain venous access and draw for lab profile and potential diagnosis testing (3 cc EDTA, 2 serum)
- once stable, perform a more comprehensive physical exam
obtain a complete history
- one of the most important and most overlooked parts of diagnosing toxicity
- once stable, question owner fully in attempt to narrow down possible causes
4 major themes to question owner about
- health status overall
- clinical signs currently
- environment at home
- diet
questions to ask about current clinical history?
- how long was problem present?
- when was animal observed sick?
- if animal was found dead-when were they last seen healthy?
- size of herd?
systems to cover for clinical signs
CNS, GI, renal, hepatic, cardiac, hematopoietic
what to learn about the environment?
type of environment where the animal lives
indoor only? fenced yard? roaming?
what to ask about diet?
what are they eating?
method of feeding?
presence of moldy or spoiled food?
water source?
water supply changes
general supportive care includes:
- ensuring adequate urine output
- monitor respiratory, cardiac and neurological status
- manage clinical signs as they develop
- manage secondary hepatic or renal injury
- administer GI protectants/anti-emetic
what is involved in symptomatic care?
-
maintain body temperature
- hypothermia: balnkets, circulating warm water pads-avoid heat lamps!
- alleviate pain
- prevent irritation of skin and membranes with demulcents, milk, sucralfate
when to decontaminate?
only after animal has been fully stabilized
what are the 2 most common types of decontamination?
emesis and activated charcoal
cathartics also used
emesis for decontamination
- potential in clincally normal animals with suspected oral exposure
- should be induced within 60 minutes of known toxic ingestion
- intubate, wash stomach 3 times with warm water until fluid is clear
- possibly save vomitus for possible analysis
when do you induce emesis?
- toxic dose of substance ingested
- no vomiting has yet occurred
- activated charcoal is not an option
activated charcoal
- prevents toxic absorption
- animal may eat, can be mixed with baby food
- earlier given = more effective
- give repeated doses ever 4-6 hours
- can give alone or after emesis
- caution: aspiration potential
activated charcoal contraindications
corrosive agents
non-polar material
4 reasons to give activated charcoal
- substance is known/thought to be absorbed by it (excluded acids, alkalis, alcohols/glycols, metals, oils, petroleum distillates, detergents)
- ingestion was very recent/undergoes eneterohepatic circulation/is sustained release
- can tolerate it
- no immediate need to administer oral meds (reasonable to wait at least 2 hours between charcoal admin and oral med)
cathartics
- decrease GI transit time, increase movement of toxins, or charcoal-toxin complex, and decrease possible absorption of the toxin
- use as adjunct to activated charcoal therapy to reduce transit time
- ex: mineral oil, saline cathar
how to prevent absorption for corrosives, strong acids and bases:
- use dilution instead of emesis
- can dilute with milk, water, or eggs
- (caution: using milk or water may enhance absorption)
dermal exposures:
may bathe in liquid dish soap, rinse well
lipid infusion
- relatively new treatment
- off label use of IV lipids
- case reports/case series demonstrates its efficacy and safety
- promising adjunct to conventional treatments
primary use and limitations for activated charcoal
- use: absorbent material with large surface area, bind most drugs
- limit: some toxins not absorbed
primary use and limitations for apomorphine
- use: emetic agent for dogs, pigs
- limit: may cause prolonged vomiting
primary use and limitations for xylazine
- use: emetic agent for cats
- limit: may cause hypotension and bradycardia
primary use and limitations for gastric lavage
- use: sustained release products, massive overdoses
- limit: invasive! risk of perforation or rupture
primary use and limitation for salt water, H2O2
- use: for at home emesis induction
- limit: might delay treatment for vet
primary use and limitation for surgical removal
- use: lead, pennies, etc
- limit: invasive!
primary use and limitation for whole-bowel irrigation
- use: removal of sustained-release pharmaceuticals, for toxins not absorbed by activated charcoal
- limit: primarily for small animals, may cause prolonged diarrhea, safer than gavage
analytic testing
- no one test that will “screen” for all known toxicants
- multiple test for specific agents can become costly
- must narrow down general type of agent involved
- test: blood, serum, urine, liver, vomitus, kidney, brain, fat
common toxins associated with an increased anion gap
ethylene glycol, ethanol, iron, methanol, salicylates, strychnine
normal anion gap
10-12 mEq/L
clinically significant anion gap
> 30 mEq/L suggests metabolic acidosis
common toxins associated with CNS depression
- ivermectin
- cholinesterase in inhibitors
- organophosphate insecticides
- carbamate insecticides
- blue-green algae
- slaframine
- lead
- locoweed
- ethylene glycol
common toxins associated with seizures
- bromethalin
- chocolate
- lead
- organophosphate insecticides
- pyrethrins/pyrethroids
- strychnine
- water deprevation/sodium ion toxicosis
- water hemlock
4 parts to accurately diagnose any toxicity
- history (health, current clinical hx, environment, diet)
- clinical signs
- pathology/necropsy
- chemical analysis
how to prevent further exposure?
- change pasture, feed, water, etc
- remove baits, old pesticides, etc
- bathe or flush for cutaneous or ocular exposure
- EDUCATE
summary of how to manage a poisoned patient
- assess ABC’s
- control seizures, cardiac
- metabolic derangements
- history
- GI decontamination
- supportive and symptomatic care
