Pediatric Toxicology Flashcards
How many toxic exposures are reported annually, and how many of those are in children?
2 million, and ~50% of those are in kids <6
Most common toxins reported
Analgesics, cosmetics, household cleaning substances
Are infant/toddler toxic exposures intentional?
Usually not, they’re just curious about their surroundings and mimic adult behaviors
What happens if a child presents with an altered level of consciousness, metabolic disturbances, neurologic dysfunction, and/or cardiac/pulmonary distress?
Include toxic exposure as part of the differential
An evaluation of a poisoned child is like that of an adolescent or an adult, but with what differences?
Supportive care, history, evaluation
Supportive care for a poisoned child
Begin with airway stabilization and administer an antidote if indicated
History of a poisoned child
Get as much detail as possible!! (Volume ingested, tablet counts, containers of substance in question and a complete review of toxic substances in vicinity when the child was first exposed)
Ask about other places the child might’ve been
PE of a poisoned child
Mental status, vitals, neurologic exam (evaluation of pupil size and reactivity)
Lab evaluation of a poisoned child
Should be directed by the history and PE, but most patients presenting with suspected poisoning should have serum chemistries and acid-base status evaluated
If there is alcohol ingestion, what lab do you obtain?
Serum osmolality
If the child ingested beta-adrenergic blockers or CCBs, what do you obtain?
ECG
Serum chemistries allow for what?
Anion gap calculation
Anion gap formula
Na - [Cl-HCO3]
What serum concentrations should you obtain (what drugs)
APAP, salicylates, ethanol, iron- all of these are widely available in many products
Gastric decontamination in pediatric poisonings
Generally not recommended
GI decontamination in peds: syrup of ipecac
NOT RECOMMENDED
GI decontamination in peds: gastric lavage
NOT RECOMMENDED
GI decontamination in peds: AC
Consider use within 1 hour in patients with a potentially toxic ingestion
AC dose in peds
0.5-1g/kg
Optimal ratio of AC to drug in peds
10:1
ADE of AC
vomiting
GI decontamination: MDAC
Administration of more than 2 sequential doses of AC
What does MDAC prevent
Prolonged absorption or enterohepatic recirculation
Repeated doses of AC may enhance what?
Gastric dialysis of certain drugs (phenobarbital, phenytoin, CBZ, amitriptyline, digoxin)
MDAC dose
Loading dose of 1g/kg, followed by 0.5g/kg q4-6h x24 hours
GI decontamination: WBI
Polyethylene glycol and electrolytes
When to consider WBI in peds patients
If they consumed SR products, EC products, iron or other metals
Route of administration for WBI
PO, but ideally NG tube in peds due to the large volume
WBI dose in peds
0.5L/hr in small children, up to 1.2-2L/hr in older children and adolescents
What should you not use for WBI and why?
MiraLax, there’s no electrolytes!
Toxic ingestion of APAP in peds
> 200mg/kg PO
60mg/kg IV
APAP toxicity in peds: GI decontamination
AC within 1 hour of ingestion
APAP antidote
NAC
(if you don’t know this by now you’re dumb)
PO NAC dose in peds
140mg/kg x1, then 70mg/kg q4h x17 doses
IV NAC dose in peds
150mg/kg infused over 1 hour
50mg/kg infusion over 4 hours
100mg/kg infused over 16 hours
IV NAC dose should be diluted to what?
40mg/ml to prevent hyponatremia
Ethylene glycol reaction
ethylene glycol → glycolaldehyde → glycolic acid → glyoxylic acid → oxalic acid
ethylene glycol is metabolized to glycoaldehyde by what?
ADH
gylcoaldehyde is metabolized to glycolic acid by what?
aldehyde dehydrogenase
Metabolite of ethylene glycol that’s responsible for the effects
Glycolic acid
Glycolic acid effects
Metabolic acidosis, cardiopulmonary compromise
How soon do the effects of glycolic acid set in?
12-24 hours after ingestion
Ethylene glycol metabolites that further exacerbate the metabolic acidosis
Glycoxylic acid, oxalic acid
Symptoms of ethylene glycol toxicity within the first few hours
decreased mental status, ataxia, slurred speech, coma
Symptoms of ethylene glycol toxicity 1-2 days after ingestion
nephrotoxicity d/t calcium precipitation of oxalic acid in renal tubules, hypocalcemia → changes in ECGs may also occur
Supportive treatment for ethylene glycol toxicity
Pyridoxine and thiamine 100mg/day (both are the same dose)
Ethylene glycol and methanol antidotes
10% ethanol, fomepizole (first-line!)
Goal of ethanol and fomepizole
Prevent accumulation of toxic metabolites and allows for renal and pulmonary elimination of parent alcohols
10% ethanol dose
8ml/kg load over 1 hour
Infusion: 0.8ml/kg/hr
10% ethanol route of administration
IV or PO
Ethanol 10% downsides
Requires central venous catheter d/t high osmolarity
CNS depression and respiratory depression
Required TDM because it can cause hypothermia, hypoglycemia, hyponatremia
Target serum concentration of 10% ethanol
100-150mg/dl
How long to continue 10% ethanol treatment for
Until toxin concentrations are <25mg/dl
Fomepizole dose
15mg/kg load
10mg/kg q12h x4 doses
15mg/kg q12h until serum concentrations of toxic alcohol are <25mg/dl
Benefits of fomepizole
No alteration in level of consciousness, BG, electrolytes
No central venous access needed
No ICU monitoring needed if patient is stable
Less dosing errors
Downside of fomepizole
It’s expensive
Methanol metabolism reaction
methanol → formaldehyde → formic acid
Methanol is metabolized to formaldehyde by what?
ADH
Formaldehyde is metabolized to formic acid by what?
Aldehyde dehydrogenase
Effects of methanol’s metabolites
Metabolic acidosis, blindness
Methanol toxicity symptoms 12-24h after ingestion
depressed mental status → tachypnea
Accumulation of formic acid can result in hallmark visual disturbances (blurriness, blindness- can be permanent)
Other signs and symptoms of methanol toxicity
GI distress, HA, shock, seizures
Is GI decontamination recommended in ethylene glycol and methanol toxicity?
NO
Household cleaners/caustic exposure: is GI decontamination recommended?
NO
Is there an antidote for household cleaner/caustic exposure toxicity?
NO
Management of household cleaner/caustic exposure toxicity
Supportive care
Fluids for asymptomatic/mildly symptomatic child
If GI injury occurs, further medical and pharmacologic management may be indicated
Signs/symptoms of foreign body ingestion
vomiting, diarrhea, abdominal pain, fever, refusal to eat/drink, dysphagia
GI decontamination for foreign body ingestion
Manual removal if esophageal impaction suspected- remove it ASAP!
Disc battery ingestion in peds
Usually, it passed through the GI system in 1-2 weeks, but sometimes it can get lodged in the esophagus and and result in burns, perforations, and fistulas
The complications of an impacted disc battery is due to what?
Alkaline electrolyte leakage from the battery → pressure necrosis and external currents generated when the battery comes into contact with tissue
Cough and cold preparations: should kids be getting these?
No, avoid these in children <6
Cough and cold preparations: GI decontamination
Use AC
Symptomatic management of cough and cold preparation toxicity
HTN- labetalol, nicardipine
Arrhythmias- amiodatone
Seizures- BZDs
How do kids get cough/cold preparation toxicity?
Given several drugs with similar ingredients, the dose-measurement was inaccurate, an adult formulation was used, or the child was given doses by multiple caregivers
