Toxicology Flashcards
What are the 5 most common exposures for less than 5 yos
Cosmetic/personal care products Household cleaning products Analgesics Foreign bodies/toys Topical preparations
How do infants compare to adolescents in toxic exposures?
Easier to obtain exposure history Typically presents within hours of exposure More likely a non-toxic exposure Typically, smaller amount ingested Larger weight-based dose
When do we include pediatric toxic exposures to assessments?
Altered consciousness Cardiac distress Metabolic disturbances Neurologic dysfunction Pulmonary distress
What do we assess in cardiopulmonary distress?
HR RR BP Temp Skin tone Skin color Hydration status Peripheral pulses Perfusion
What is the antidote for Heparin?
Protamine
What is the antidote for Cyanide
sodium amyl nitrite/sodium thiosulfate
What is the antidote for TCAs and salicylates
Sodium bicarbonate
What is the antidote for warfarin
Vit K
What is the antidote for diphenhydramine
Benzos/sodium bicarbonate
What is the antidote for benzocaine
Methylene blue
What is the antidote for propranolol
Pressor support
Glucagon
Insulin
Dextrose
How is APAP metabolized
Glucoronidation (increases until age 3) Sulfation CYP450 Glutathione Covalent binding - APAP-protein causes cell death
Antidote for APAP
N-acetylcysteine (NAC)
ADR of IV NAC
Anaphylactoid reaction
What is measured in metabolic disturbances in pediatric poisonings
Basic metabolic panel changes
Anion gap changes
Serum concentrations as warranted
Basic metabolic panel
Na K CO2 BUN Scr Glu
Anion gap equation
Na - [Cl + Co2]
What causes an elevated anion gap
M - Methanol U - uremia D - Diabetic ketoacidosis P - Propylene glycol I - Isoniazid, iron, infection L - Lactic acidosis E - Ethanol, ethylene glycol S - Salcylates
Pediatric decontamination
Activated charcoal
Syrup of ipecac
Gastric lavage
Bowel irrigation
How does activated charcoal work in pediatric poisonings
High SA promoting absorption Ionic binding and van der Waals forces bind toxins Give = 1 hour post ingestion 10 activated charcoal per 1 toxin Does not effectively absorb EtOHs 0.5-2 g/kg in pediatric pts
How does syrup of ipecac work in poisonings
Stimulates chemoreceptor trigger zones
Vomiting occurs within 20 minutes
How does gastric lavage work in poisonings
10ml/kg warm water instilled and removed until contents are clear
How does bowel irrigation work in poisonings
Pharmacologic stimulation of the GI tract
PEG and/or electrolyte flushes
For this to work it needs to be further down GI tract
IV NAC administration
24 hour infusion
IV NAC concentration issues
More free water (hyponatremia, seizures)
40 mg/ml
Enteral NAC ADR
N/V/D
Enteral NAC administration
72 hour regimen
Ethylene glycol (where is it found, why is it ingested)
Engine coolant
Sweet taste
What are the steps in metabolism of ethylene glycol
Ethylene glycol to glycoaldehyde via alcohol dehydrogenase
Glycoaldehydre to glycolic acid via aldehyde dehydrogenase
Glycolic acid to glycoxylic acid
Glycoxylic acid to oxalic acid
ADRs of Ethylene glycol
< 5 hours Ataxia CNS depression Coma Mental Status Change
ADRs of glycolic acid
12-24 hours
Metabolic acidosis
ADRs of glycoxylic acid
Metabolites 12-24 hours CV collapse CHF Respiratory depression Tachycardia
ADRs of oxalic acid
1-3 days ECG changes Hypocalcemia Nephrotoxicity Tetany
Supportive care of ethylene glycol poisonings
Thiamine (100 mg/d)
Pyridoxine (100 mg/d)
Methanol locations
Solvents
Antifreeze
Fuels
Windshield wiper fluid
Methanol supportive care
Folic or folinic acid 1 mg/kg q4-6h
Methanol/ethylene glycol toxicity therapies
Ethanol
Fomepizole
Higher affinity for alcohol dehydrogenase than toxins (Fomepizole > ethanol)
Continue until toxin concentration < 25
Ethanol administration
IV or enteral IV requires central access Goal serum concentration: 100-150 LD: 8ml/kg/h of 10% ethanol over 1 hour MD: 0.8 mL/kg/h continuous infusion
Ethanol ADRs
CNS depression Hypoglycemia Hyponatremia Hypothermia Respiratory depression
Fomepizole MOA
Competitive alcohol dehydrogenase inhibitor
Fomepizole advantages
No central access required
No mental status changes
No metabolic variations
Fomepizole administration
LD: 15 mg/kg x 1, then 10 mg/kg q12h x 4
MD: 15 mg/kg q12h
S/sx of toxic opioid exposures
Attention impairment Coma Constipation Drowsiness Loss of consciousness Memory impairment Nausea Pupillary constriction Respiratory depression Over sedation Slurred speech
Naloxone/Naltrexone MOA
Pure opioid antagonist
Competitive inhibitor
Naloxone dosing for toxic opioid exposures
= 20 kg: 0.1 mg/kg/dose
> 20 kg: 2 mg/dose
Every 2-3 minutes
Naltrexone dosing
Titrate up once opioid free
Typical MD - 50 mg/d
Once daily dosing
Antidote for organophosphates/carbamates
Atropine/pralidoxime
Antidote for malignant hyperthermia caused by the disease process such as neuroleptic malignant syndrome or heat stroke; caused by drug toxicity such as from monoamine oxidase inhibitors or baclofen withdrawal
Dantrolene
Antidote for iron
Deferoxamine
Antidote for dig
digifab
Antidote for benzos
Flumazenil
Antidote for lead
Edetate calcium disodium (EDTA)
Dimercaprol
Succimer
Antidote for methemoglobinemia
Methylene blue
