Tox- Small Animal Toxicology Clinical Approach

kelseyfmeyer's version from 2016-11-28 18:03


Question Answer
what is the tox which is SUPER CRITICAL for you to know when it was ingested?ethylene glycol
potential complications of ocular exposures?Corneal ulceration, Localized irritation, scarring, vision impairment, blindness.
exs of eye irritants?Acids, alkali, solvents, alcohol, detergent
tx if there is an ocular exposure?IRRIGATION ASAP!!!! can use saline, tepid tap water, distilled water. Do for 20-30min, from MEDIAL TO LATERAL
which direction do you flush the eye in?MEDIAL TO LATERAL (prevent flushing into other eye)
local vs systemic effects of dermal exposures? tx?local: burns, irrigation, allergic dermatitis. Systemic: due to toxin absorption should monitor pt. Tx: RINSE OR BATHE with mild dish soap. NOT insecticidal shampoos, or detergents
what should you know about GI decontamination? what are some methods?it is extensively used but there is a lack of evidence based rationale. However, (1) gastric evacuation (emesis) and (2) admin of agents (such as charcoal).... are used to reduce exposure or enhance elim.
CONTRAINDICAtIONS for gastric evacuation (induced emesis) (5)Caustic agents, Petroleum based product (Abolishes gag reflex), Neuro patients (No airway protection), Recent abdominal surgery, Cardio unstable patients
which is more effective- apomorphine or H2O2?equally effective
what is the MOA for H2O2?ONLY PERIPHERAL NOT CENTRAL= acts via irritation, within MINUTES!
dose for H2O2 to induce emesis?1ml/kg PO
adverse effects of H2O2 to induce emesis?hemorrhagic gastritis, salivation (bc works via irritation!)
what % solution of H2O2 to induce emesis?3%
Syrup of ipecac- MOA? Dose? adverse effects?MOA is that it has alkaloids (emetine, cephaeline), which work both CENTRALLY AND PERIPHERALLY- irritate stomach and also CRTZ stim. DOGS: 1-2.2ml/kg. CATS: 3.3ml/kg diluted equally in water. ADVERSE EFFECTS: Humans – diarrhea, drowsiness, cardio toxicity
emetic of choice for dogs?APOMORPHINE HYDROCHLORIDE
Apomorphine hydrochloride: what is it? MOA? Use in who? Dose?It is a synthetic opiate which works CENTRALLY by working on CRTZ, it is the emetic of choice for dogs. can give IV (0.03mg/kg), or IM (0.04mg/kg), OR conjunctival admin.
adverse effects of apomorphine hydrochloride? Reversal?can cause Sedation, protracted vomiting, restlessness, excitement... but luckily can reverse with naloxone
DOC for emesis induction in cats?alpha-2 agonist (xylazine) (...maybe)
alpha 2 agonist (xylazine she prefers over dexmedetomidine) MOA for inducing emesis? dose/route?Xylazine hydrochloride MOA is CENTRALLY with the CRTZ. Is possibly the emetic of choice in cats. 0.44 – 1.1 mg/kg IM or SC (*Plumb)
adverse effects of xylazine (a-2 agonist) as used for inducing emesis? reversal?Bradycardia, arrhythmias, muscle tremors.... reversal with YOHIMBINE
what things are NOT recommended for inducing emesis?liquid dishwashing detergents (can cause aspiration and bloating), table salt (enough to cause vomiting would also lead to probs with hypernatremia), mustard powder is probably toxic, and mechanical stimulation (shoving fingers down throat) might lead to trauma,, asphyxiation, and bite injury
Whole bowel irrigation: What can you use to do this? How do you admin?need a Osmotically balanced solution, such as polyethylene glycol solutions. Admin via a nasogastric tube. “until effluent resembles infusate”
contraindications of whole bowel irrigation?GI hemorrhage, bowel obstruction, perforation
how do you place a nasogastric tube?Prime tube with sterile saline & lubricate end--> Pre-measure and mark tube (nares to 13th rib)--> Apply local anesthetic drops to nostril--> Advance tube in a ventral-medial direction to pre-marked location--> Suture to side of nostril--> Radiograph confirms placement
what is the reasoning behind gastric lavage? how do you do this?Removal of toxic substances from stomach, will need to do orogastric intubation, preferably under general anesthesia.
CONTRAINDICATIONS for gastric lavage?Hydrocarbon ingestion (aspiration), Corrosive substances, When the risk of GI perforation is high (ulceration, recent sx)
when is gastric lavage most effective? Most effective w/in 1-2 hrs of ingestion!
gastric lavage procedure Anesthetize patient--> Airway protected – cuff inflated, ET tube--> Patient in lateral recumbency--> Head lower than thorax--> Pre-measure tube (tip of nose to 13th rib)--> Fenestrated tube end passed in oral cavity to mark--> Confirm tube placement (aspirate gastric juice or do rads). once confirmed, can lavage with Warm water or saline (5-10ml/kg), and gravity flow for drainage (head lower than thorax!), repeat till clear
if you are gonna remove a gastric lavage tube, what should you do?occlude it, so doesnt drag acid all over
placing any tube into belly means pre measuring to what rib?13th rib!!
what should you know about effectivity of gastric lavage?Three studies in animals have failed to demonstrate significant amounts recovered. (might get up to 38% if performed within 15-20 min....up to 13% after 60min)
risks with gastric lavage?Mechanical damage (eso, soft tissues, pharynx), Aspiration pneumonia!!, Electrolyte imbalances (hypoxia and hypercapnea in humans)
Adsorbents--> activated charcoal--> can come in many formulations (Granules, tablets, capsules, suspension) but what toxins doesnt it bind??Xylitol and alcohol
factors which affect efficacy of activated charcoal?Temperature, pore size, surface area, solubility of toxin, pH, presence of food (?)
what are the two types of cathartics? (how do they work/examples)they accelerate expulsion from GI tract, stim peristalsis (1) Saccharides (sorbitol): metabolized to fructose, works osmotically, might risk dehydration and inc Na conc in body (2) Saline laxatives: magnesium sodium citrate (Studies show sorbitol acts quicker than saline)
cathartics are often combined with...charcoal
how many times to you admin cathartics?ONLY ONCE-- risk dehydration and diarrhea
CONTRAINDICATIONS for cathartics?Bowel surgery, GI obstruction, Perforation, Heart disease
other misc considerations for detoxDiuresis, Hemodialysis, Hemoperfusion, Ion trapping
how do you do forced diuresis? cautions? Large volume IV fluids--> Increase GFR & filtration fraction. Enhance elimination. Caution: vol overload, pulm edema
two toxins Hemodialysis & Hemoperfusion is particularly helpful for?Ethylene glycol, Acetaminophen
Intravenous lipid therapy: how does this work? Why do we do it?do for Lipophilic drug toxicity (avermectins, LAs, beta blockers, Ca++ channel blockers, tricyclic antidepressants). For the therapy, use sthing like soybean oil (long chain fatty acids) which inc energy production, alter kinetics, and create a "lipid sink". (give 20% solution as a 1.5ml bolus or 0.25ml/kg/min CRI)
how does ion trapping work, how popular is it?generally does by urinary manipulation (acidification, alkalinization), which traps molecules in ionized form which enhances elim and prevents resorption. Not generally recc tho, can cause acid-base balances

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