Transcript Peds Tox 2001

Poisoning in Children
Kent R. Olson, MD
Medical Director, San Francisco Division
California Poison Control System
Clinical Professor of Medicine, Pediatrics
and Pharmacy, UCSF
Case study:
• A 2 year old child is found with a bottle of
his mother’s prenatal vitamins
• Spontaneous vomiting after 30 minutes
• Paramedics report systolic BP 70/p, HR
130/min
Most common pediatric exposures*
Category
Hazard Factor
• Cosmetics
0.2
• Cleaning agents
0.9
• Plants
0.1
• Analgesics
0.6
• Cough & cold preparations
0.5
• Hydrocarbons
2.2
Data from AAPCC 1985-1989
Relative risk of death/major effect
Category
• Rattlesnake bite
• Strychnine
• Alkaline drain cleaner
• Organophosphates
• Anticoagulants
• Cosmetics
Hazard Factor
244
50
22
5.6
0.9
0.2
Pediatric poisoning deaths
(AAPCC 1985-1989)
Pharmaceuticals
Hazard Factor
• Iron
8.5
• Tricyclic antidepressants
17.7
• Cardiovascular drugs
8.1
Non-pharmaceuticals
• Pesticides
• Hydrocarbons
• Methanol
Hazard Factor
2.1
2.2
5.1
More recent data - AAPCC 1999
24 deaths in children < 6
Pharmaceuticals
• Opioids (3)
• Iron (1)
• Nifedipine (1)
Non-pharmaceuticals
• Carbon monoxide (7)
• Hydrocarbons (3)
• Ammonium bifluoride (2)
Case 1:
Abdominal
X-ray
Iron poisoning in children
• Leading cause of childhood poisoning
deaths
• Pathophysiology:
– corrosive effect on GI tract
– cellular toxin
• Toxic dose > 40-60 mg/kg elemental Fe
– adult strength preparations much more likely
to cause toxicity than children’s chewables
Iron poisoning: clinical findings
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Vomiting
Diarrhea
Hypotension
Metabolic acidosis
Leukocytosis, hyperglycemia
Radiopaque pills on plain x-ray
Late complication: hepatic failure
Treatment of iron poisoning
• Volume replacement
– IV crystalloid boluses
• Chelation therapy
– deferoxamine (Desferal) is specific chelator
– Iron chelate complex  “vin-rose” urine
– IV route preferred (don’t use IM “test dose”)
– avoid prolonged deferoxamine therapy
Gut decontamination
for iron ingestion
• Home:
– consider ipecac-induced emesis if recent OD
– argument against ipecac: it masks
spontaneous vomiting
• Hospital:
– ipecac or gastric lavage? Neither very effective
– lavage with HCO3, PO4? Dangerous
– whole bowel irrigation = best method
Whole bowel irrigation
• Balanced electrolyte solution with nonabsorbable polyethylene glycol (PEG)
– no electrolyte disturbance
– no net fluid gain or loss
– well-tolerated
• Method: GoLytely™ or Colyte™
– 500 mL/hour by gastric tube until rectal
effluent clear
– Adolescents/adults: 1-2 L/hr
Case study:
• A toddler is found with an open daily
medicine container belonging to his
grandmother.
• Usual contents:
– Lasix 40 mg
– Cardizem-CD 240 mg
– Multiple vitamin
• Container is now empty. Child asx.
ECG in a patient with verapamil OD
Decreased
Automaticity
& Conduction
Negative
Inotropic
Effects
Dilated Vascular
Smooth Muscle
HR
AV Block
CO
SVR
SHOCK
Calcium Channel Blocker Poisoning
Calcium antagonist toxicity
• Shock caused by combination of:
– Decreased automaticity & conduction
– Negative inotropic effects
– Vasodilation
• Treatment with calcium
– most effective for negative inotropic effect
– high doses may be needed
– in the future: insulin + glucose?
Case study:
• An 18 month old is brought to the ER after
a seizure
• No prior seizures
• No recent illness or fever
• HR 140/min, BP 105/70
• Pupils dilated
• Skin flushed, dry
Case 2: ECG
Common drug-induced seizures
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Tricyclic antidepressants
Cocaine & amphetamines
Theophylline
Diphenhydramine
Isoniazid (INH)
Phenothiazines
Strychnine
Many others (camphor, lindane, etc)
Case study, cont.
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ECG monitor shows wide QRS complex
Repeat BP 70/p
The child is intubated endotracheally
A therapeutic drug is given:
Tricyclic
antidepressant OD
• “Three C’s”
– coma
– convulsions
– cardiac conduction
defects
… AND
•Anticholinergic effects
–dilated pupils
–tachycardia
–jerking movements
Treatment of TCA overdose
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ABCs
No ipecac! (use AC orally or by NG)
Monitor asx child for at least 6 hours
QRS prolongation:
– Caused by Na channel block
– Rx = Sodium Bicarbonate
– 1-2 mEq/kg IV bolus
• Do NOT use physostigmine
Another Case
• A child is found with an open container of
“wire wheel cleaner”
• Contents:
– ammonium bifluoride
– hydrofluoric acid
• Child initially asymptomatic
Fluoride toxicity
• Sources:
– wire wheel cleaners, degreasers, rust and
water stain removers
– fluoride tablets and drops
• Toxicity:
– hypocalcemia (even from dermal exposure)
– hyperkalemia
– ventricular fibrillation
• Treatment: Calcium (oral and IV)
Case study:
• A 16 year old takes several “happy pills”
provided by a friend.
• Develops a headache, vomits once.
• In ER:
– awake, alert, c/o headache
– HR 38/min (w/2nd degree AV block)
– BP 166/100 mm
Phenylpropanolamine
• Common OTC product
• May be used to get “high”
(not very effective)
or as suicidal agent
• Hypertension common, often with reflex
bradycardia or even AV block
– intracranial hemorrhage may occur
• Treat with vasodilator, e.g. phentolamine,
nitroprusside
11-6-2000: FDA’s MedWatch
• “FDA is taking steps to remove
phenylpropanolamine hydrochloride from
all drug products due to the risk of
hemorrhagic stroke...
• “... FDA has significant concerns because
of the seriousness of stroke and the
inability to predict who is at risk …”
Gut decontamination
• Current consensus:
– Gut emptying of limited value
– AC alone probably fine in most patients
• Some twists:
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–
–
–
SI still useful at home w/in 5-10 min?
Lavage for selected cases?
Role of Whole Bowel Irrigation?
What about home AC?
Anyone
for
charcoal?
Use of ipecac is declining
Year
1983
1988
1993
1998
Source: AAPCC 1999
Ipecac used
13.4%
8.4%
3.7%
1.2%
Final “stumper”
• 9 month old being watched by
grandmother
• Found flaccid, grunting, with decreased
level of consciousness
• HR 70/min, BP 105/59
• Respirations agonal, O2 sat 80%
• Pupils pinpoint
More information . . .
• No response to naloxone
• Treated supportively, eventually recovered
• Initial history: grandmother takes
lisinopril, HCTZ
• Also using eye drops for glaucoma
Continued
• Alphagan™ (brimonidine 0.2%)
– used for open-angle glaucoma
• Stimulates -2 receptors (similar to
clonidine)
– CNS depression, bradycardia, HOTN
– Peripheral: alpha-agonist can elevate BP
California Poison Control System
• Public Hotline: 1-800-876-4766 (8-POISON)
• Health Professionals: 1-800-411-8080
• 300,000 exposures/year
– 2/3 are kids
– also: suicides, occupational, hazmat,
veterinary, consumer product recalls, ...
• Most kids can be managed at home
– PCC can communicate with 9-1-1 or
paramedics on scene