poisoning in children kent r. olson, md medical director, san francisco division california poison...
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Poisoning in ChildrenPoisoning in Children
Kent R. Olson, MDMedical 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 preparations0.5• Hydrocarbons 2.2
Data from AAPCC 1985-1989
Relative risk of death/major effect
Category Hazard Factor• Rattlesnake bite 244• Strychnine 50• Alkaline drain cleaner 22• Organophosphates 5.6• Anticoagulants 0.9• Cosmetics 0.2
Pediatric poisoning deaths(AAPCC 1985-1989)
Pharmaceuticals Hazard Factor• Iron 8.5• Tricyclic antidepressants 17.7• Cardiovascular drugs 8.1
Non-pharmaceuticals Hazard Factor• Pesticides 2.1• Hydrocarbons 2.2• Methanol 5.1
More recent data - AAPCC 199924 deaths in children < 6
Pharmaceuticals• Opioids (3)• Iron (1)• Nifedipine (1)
Non-pharmaceuticals• Carbon monoxide (7)• Hydrocarbons (3)• Ammonium bifluoride (2)
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
• 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 non-absorbable polyethylene glycol (PEG)– no electrolyte disturbance– no net fluid gain or loss– well-tolerated
• Method: GoLytelyGoLytely™™ or ColyteColyte™™– 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.
Negative InotropicEffects
Negative InotropicEffects
DecreasedAutomaticity& Conduction
DecreasedAutomaticity& Conduction
Dilated VascularSmooth Muscle
Dilated VascularSmooth Muscle
SVRSVRCOCOHRHRAV BlockAV Block
SHOCKSHOCKSHOCKSHOCK
Calcium Channel Blocker PoisoningCalcium 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
Common drug-induced seizures
• Tricyclic antidepressants• Cocaine & amphetamines• Theophylline• Diphenhydramine• Isoniazid (INH)• Phenothiazines• Strychnine• Many others (camphor, lindane, etc)
Case study, cont.
• 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
• 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:– SI still useful at home w/in 5-10 min?– Lavage for selected cases?– Role of Whole Bowel Irrigation?– What about home AC?
Use of ipecac is declining
Year Ipecac used
1983 13.4%
1988 8.4%
1993 3.7%
1998 1.2%
Source: AAPCC 1999
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