Poisons and Environmental Toxins Flashcards
Kids are at increased risk for manifestation of what toxicity effects over the course of their lifetime as compared to adults?
Latent toxicity effects
What toxin does the placenta specifically block?
Cadmium
Can lead transfer across the placenta?
Yes
What toxin does the placenta enhance the passage of?
Mercury
What 2 toxins can cross the placenta easily due to their lipophilic nature and low molecular weight?
PCBs and insecticides
What 3 toxins could you see in water?
- E. coli
- Cryptosporidium
- Mercury
What common thing ingested can contain many toxins, especially if not handled correctly?
Food
What is the appropriate dosing of activated charcoal?
0.5 to 1 g/kg, up to an adult dose range of 25 to 100 g
What can be given to expedite exit of an ingested substance (toxin) and reduce enterohepatic excretion?
Cathartics (magnesium citrate and sorbitol)
What is always an incorrect treatment for toxin ingestion on boards?
Syrup of ipecac
What are some reasons kids are at an increased risk from toxic exposures compared to adults?
In utero, smaller size means more vulnerable to an equivalent toxic exposure. Kids put more non-food items in mouth, increased risk for exposure to toxic agents in environment.
If you are giving activated charcoal to a patient at risk for respiratory depression (like phenobarbital overdose), what else should you do?
Intubation, then give charcoal with an NG tube
What can’t you give activated charcoal with?
Antidotes (it would interfere with the absorption of the antidote)
What is the one antidote you can give with activated charcoal and why?
N-acetylcysteine (since it is given in such large quantities)
What are the toxic substances that are “calmly” removed without charcoal?
Cyanide
Alcohol
Lithium
Heavy Metals
Charcoal is a poor choice for these
When would you do gastric lavage?
Use is reserved for potential life-threatening ingestions that have occurred within 60 minutes of seeking medical attention
*Gastric lavage is no longer recommended for most infections…risk outweighs benefits
With toxin ingestion what should you do first?
Address ABCs and search for the specific cause later
Most treatment for toxins is supportive
If you are presented with an unstable patient, what is the correct answer?
Secure the airway
When do the initial manifestations of acetaminophen toxicity occur?
First 24 hours
What are the initial symptoms of acetaminophen toxicity?
Anorexia, nausea, vomiting
In cases of significant acetaminophen toxicity, what happens during the latent phase and how long does this last?
Liver enzyme levels rise significantly, lasts 1-4 days
With severe acetaminophen toxicity, what happens after the latent phase (1-4 days where liver enzyme levels rise)?
Jaundice and liver tenderness
What is the most important predictor of outcome regarding acetaminophen toxicity?
Level taken 4-10 hours post ingestion
Why is immediate discharge from the ED when the person is asymptomatic following acetaminophen ingestion always the wrong answer?
It is very common to be asymptomatic initially, with liver toxicity presenting later on
What is done for someone with acetaminophen ingestion when it has been less than 4 hours since ingestion?
Give activated charcoal to reduce absorption
What is done after giving someone with acetaminophen ingestion activated charcoal?
Get an acetaminophen level 4-24 hours post ingestion and plot level on published nomogram to determine risk for hepatotoxicity
You give N-acetylcysteine without obtaining acetaminophen levels when?
If it is determined that more than 140 mg/kg has been ingested
*Especially if it would delay initiation of treatment longer than 10 hours after ingestion
What does N-acetylcysteine do?
Prevents the accumulation of toxic metabolites of acetaminophen
How is acetaminophen overdose diagnosed?
By a history of ingestion of 140mg/kg or more
How is acetaminophen toxicity diagnosed?
By the level in the nomogram
How late can the transaminase levels rise in acetaminophen overdose?
3-4 days after ingestion (LFTs can be normal 2-3 days after ingestion, even in cases of severe overdose)
“Wintergreen” odor on breath is clue to what ingestion?
Salicylate
What can cause salicylate toxicity?
ASA ingestion along with medications that contain salicylates
What is initial management of salicylate ingestion?
Activated charcoal
What is given to correct metabolic acidosis in salicylate ingestion?
Sodium bicarbonate (alkalinize the urine)
What causes metabolic acidosis in salicylate ingestion?
Not directly caused by salicylates, but typically by respiratory alkalosis and by a build up of organic acids as a result of salicylate action in cells
What two electrolytes should you worry about in salicylate ingestion?
Hypokalemia and low glucose (consider glucose even if not hypoglycemic)
What should be calculated when presented with acidosis and values for sodium, potassium, chloride, and bicarbonate?
Anion gap
What is the formula for anion gap?
Sodium - (Chloride + Bicarbonate)
What happens to the anion gap in salicylate poisoning?
It is elevated
Do kids with salicylate toxicity get fever?
Yes…don’t just assume sepsis if you have other clues consistent with salicylate toxicity
What are symptoms of ibuprofen ingestion?
Usually asymptomatic, but for boards at least nausea and vomiting
What is management of ibuprofen overdose?
Primarily supportive
If you get steen who ingested ibuprofen for a suicide attempt who is physically stable, what is the best next step?
Go after risk for co-ingestion and choose the answer that is a level for another drug (salicylate or acetaminophen)
Don’t choose ipecac, gastric lavage, or ibuprofen level (it doesn’t exist)
How might ethanol toxicity be presented on boards in kids?
- Adolescent who is having a seizure and is hypoglycemic
2. Toddler who got hold of drinks left over after a party the night before and parents found him unresponsive
What constitutes a mild blood alcohol level?
What are symptoms of mild blood alcohol levels?
Euphoria, lowered inhibitions, and impaired coordination
How do you treat mild ethanol toxicity?
Watch them
What is a moderate blood alcohol level?
> 0.2 g/dL, 200 mg/dL, 0.2% BAC
Clinical presentation of moderate blood alcohol level?
Slurred speech, ataxia, impaired judgement, mood swings
Management for moderate ethanol toxicity?
Monitor until sober
What is a severe blood alcohol level?
> 0.3 g/dL, 300 mg/dL, 0.3% BAC
Symptoms for severe ethanol toxicity?
Confusion and stupor
What ethanol level is potentially lethal causing coma, respiratory depression, and death?
Greater than 0.4 g/dL, 400 mg/dL, 0.4% BAC
What is important to monitor in a patient with ethanol toxicity?
Hypoglycemia and electrolyte imbalance
What can ethanol intoxication mask?
Toxicity of other drugs
Where an you find ethyl alcohol?
Mouthwash, cough and cold preparations, elixirs, colognes, perfumes
*Presentation of ethanol toxicity might not be obvious…
Where is methanol found?
Rubbing alcohol, windshield washer fluid, cooking fuel, perfumes, antifreeze
Abdominal pain and vomiting, inebriation, severe metabolic acidosis, increased anion gap, CNS depression
Methanol toxicity
Does methanol ingestion cause immediate signs of toxicity?
Not necessarily (same with situation of a child acting drunk after ingesting ethanol)
What does methanol get broken down into?
Formic acid and formaldehyde
What horrible things can formic acid and formaldehyde (methanol toxicity) cause?
Havoc on liver and optic nerve (blurred vision, “snow field” vision, and edema of the optic disc)
What can be given for methanol toxicity?
- Ethanol…serves as an alcohol dehydrogenase antagonist and slows conversion of methanol to formaldehyde
- 4-methypyrazole (4-MP)…only approved in Europe right now, but it does the same thing as ethanol with less toxicity
- Sodium bicarbonate (helps counter formic acid)
What BAC is considered legally under influence in most states?
0.08%
What is a BAC of 0.08% equivalent to in g/dL or mg/dL?
0.08 g/dL or 80 mg/dL
Toddler who is lethargic, in respiratory distress, sweating, wheezing, kid was in a backyard shed….
Organophosphate poisoning (hinting at insecticide exposure)
Muscle twitching, salivary secretions, urination, GI cramps
Organophosphate poisoning…(“Overstimulated person playing the organ”)
What routes can someone get organophosphate poisoning?
Ingestion, inhalation, absorbed through skin
What is the mechanism of action for organophosphate poisoning?
Organophosphates inhibit acetylcholinesterase…so the effects are due to acetylcholine overload- Cholinergic effects
What are cholinergic symptoms?
“Fight or flight” … In a rush, you create slush (SLUDGE)
- Salivation
- Lacrimation
- Urination
- Defecation/Diarrhea
- Gastrointestinal
- Emesis
What is the other pneumonic to remember cholinergic side effects besides SLUDGE)?
DUMBBELS
- Diarrhea
- Urination
- Miosis
- Bronchospasm
- Bradycardia
- Emesis
- Lacrimation
- Salivation
What effects can long term insecticide exposure have on a child’s health?
Issues with brain development
What is one big source of insecticide exposure for kids?
Unwashed fruit and vegetables…kids are more likely to be exposed in general due to behavioral factors
What are the 2 categories of cholinergic effects?
Muscarinic and nicotinic
What are the cholinergic muscarinic effects?
Salivation, lacrimation, diarrhea, wheezing, bradycardia
What do you give to manage muscarinic cholinergic effects?
Atropine
“Muskrat”: “Musc”arinic effects need “at”ropine
What are the nicotinic cholinergic effects?
Primarily neuromuscular…weakness, paralysis, muscle fasciculations
How do you treat nicotinic cholinergic effects?
Pralidoxime