8/27 - Clinical Toxicology

Toxicity

GI signs, acute hepatic injury or failure, acute kidney injury, seizures, tremors, comatosity, acute respiratory distress, acute congestive heart failure, and arrhythmias can all indicate what clinical emergency?

Triage, History

If a patient presents with a known ingestion of a known toxic substance, either before or after clinical signs have started, you should first do/take what two things about that patient?

Decontamination

What treatment approach to toxicity can be either dermal, gastric, or blood, depending on the agent, route, or other factors?

Dermal

What type of decontamination uses dishsoap as a degreaser, with multiple baths to decontaminate this tissue/organ? Ocular decontamination is also part of this step if necessary.

Gastric

What type of decontamination uses either emesis, gastric lavage, or activated charcoal?

Emesis

Which route of gastric decontamination is indicated in toxin ingestion less than 1 hour, asymptomatic patients, unknown time of ingestion if asymptomatic, or the toxin is known to stay in the stomach for a long time (grapes, raisins, chocolate, xylitol, amitraz collar)? It is contraindicated in corrosive toxins, symptomatic patients, and if underlying disease predisposes the patient to aspiration pneumonia.

Alpha-2 agonists

Which type of drugs can be used to induce emesis in cats? Xylazine and dexmedetomidine are two examples.

Apomorphine, hydrogen peroxide

Which two drugs/substances can be used to induce emesis in dogs?

Gastric Lavage

Which gastric decontamination technique is used in small animals and is more effective than emesis? It is not effective over an hour after ingestion. It requires an IV catheter, sedation/anesthesia, ET tube, and charcoal administration. It can also be done in horses (emesis is not possible in horses) and requires a large bore tube with holes on the side, sedation if necessary, copious amounts of water (2-4 liters), saving some fluid for chemical analysis, and charcoal administration. It is indicated when drug dose approaches LD50, if a drug has a narrow safety margin and severe clinical signs, if the patient is clinical and emesis is contraindicated, or if emesis was non-productive.

Activated Charcoal

What drug can be used as the second step of gastric decontamination or can be used on its own? It is often used during gastric lavage and should be given as soon as possible after ingestion. Up to 6 hours post-ingestion this may still be beneficial, such as with extended-release tablets or enterohepatic recirculation. It is indicated when the toxin is known to bind to it, if the toxin has enterohepatic recirculation, if the toxin is unknown, and if there is normal CNS awareness and normal airways. It is contraindicated if there are heavy metals, xylitol, or ETOH, or if there is salt toxicosis, corrosives, or hydrocarbons. It is also contraindicated if there is no gag reflex or if the patient is dehydrated.

Cathartic

What type of substance, such as sorbitol, is given along with the first dose of activated charcoal? It is not given in the subsequent doses. Multiple doses of activated charcoal are indicated for antidepressants, theophylline, digoxin, phenobarbitol, XR/ER formulations, or if there is enterohepatic recirculation.

Blood

What type of decontamination involves hemoperfusion via hemodialysis, using an activated charcoal filter? It can use IV lipid emulsion, such as with avermectins, local anesthetics, b-blockers, Ca-blockers, or tricyclic antidepressants. In large animals it is not always practical.

Isotonic Crystalloid

What type of fluids are the key general supportive care for toxicosis cases? This corrects dehydration, hypovolemia, and accounts for GI loss, and supports organs that could be affected. It also dilutes and helps in diuresis (true diuresis by forcibly increasing urine production).

Antiemetics

What type of drugs should be given after emesis has been performed, if the toxin is a gastric irritant, or if activated charcoal causes nausea?

Antacids

What type of drugs should be given if the toxin is known to cause ulcers, or if patient factors like IBD or hypoadrenocorticism are involved?