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Poisoning

Poisoning is defined as exposure to an agent that can cause organ dysfunction, leading to injury or death. Children less than 6 years of age account for 60.8% of poisonings.

Clinical evaluation of poisoning

The type of toxin involved should be determined. The time of the exposure and how much time has elapsed should be determined.

Poisonings Among Children Under 6 Years Old

Toxin

Percentage

Pharmaceuticals

Analgesics

21.4

Cough/cold preparations

17.3

Topical agents

1.9

Antimicrobials

8.5

Vitamins

8.0

Gastrointestinal preparations

7.0

Hormones

4.2

Minerals/diuretics

3.2

Antihistamines

3.1

Psychopharmaceuticals

2.7

Cardiovascular drugs

2.5

EENT preparations

2.1

Asthma medications

1.8

Stimulants/street drugs

1.0

Non-pharmaceuticals

Cleaning products/polishes/deodorizers

20.9

Cosmetics/grooming

19.2

Plants/mushrooms/tobacco

16.1

Foreign body/battery/toys

7.8

Pesticides/herbicides/fungicides

7.4

Chemicals

5.3

Hydrocarbons

4.9

Arts/crafts

3.8

Paints/strippers/adhesives/glues

3.8

Alcohols

3.0

Bites/envenomations

2.1

Food poisoning

2.1

 

The dose of the toxin should be assumed to be the maximum amount consistent with the circumstances of the poisoning.

Munchausen syndrome by proxy

Chemical child abuse should be suspected when childhood poisonings are associated with an insidious and/or inexplicable presentation (eg, recurrent acidosis, polymicrobial sepsis, recurrent malabsorption syndrome, factitious hypoglycemia, failure to thrive).

The syndrome is referred to as "Munchausen syndrome by proxy" when the abuse is perpetrated by a caretaker. Agents may include aspirin, codeine, ethylene glycol, fecal material, insulin, ipecac, laxatives, phenothiazines, table salt, and vitamin A.

Physical examination

The first priority in a severely poisoned child is to maintain an airway, ventilation, and circulation.

The vital signs, breath odors, skin, gastrointestinal, cardiovascular, respiratory, and neurologic systems.

 

Physical Findings Associated with Specific Drugs and Chemicals

Symptom or Sign

Agents

Fever

Amphetamines, anticholinergics, antihistamines, aspirin, cocaine, iron, phencyclidine, phenothiazines, phenylpropanolamine, thyroid, tricyclic antidepressants

Hypothermia

Barbiturates, carbamazepine, ethanol, isopropanol, narcotics, phenothiazines

Breath odors:

Mothballs

Fruity

Garlic

Bitter almond

Peanuts

 

Naphthalene, paradichlorobenzene

Isopropanol, acetone, nail polish remover

Arsenic, organophosphates

Cyanide

 

N-3-pyridylmethyl-N-4-nitrophenylurea (VACOR rat poison)

Hypertension

Amphetamines, cocaine, ephedrine, ergotism, norepinephrine, phenylpropanolamine, tricyclic antidepressants (early)

Hypotension

Antihypertensives, arsenic, barbiturates, benzodiazepines, beta blockers, calcium channel blockers, carbon monoxide, cyanide, disulfiram, iron, nitrites, opiates, phenothiazines, tricyclic antidepressants (late)

Tachypnea

Amphetamine, cocaine, carbon monoxide, cyanide, iron, nicotine, phencyclidine, salicylates

Hypoventilation

Alcohols, anesthetics, barbiturates, benzodiazepines, botulism, chlorinated hydrocarbons, cholinesterase-inhibiting pesticides, cyclic antidepressants, narcotics, nicotine, paralytic shellfish poisoning, solvents, strychnine

Coma

Alcohols, anticonvulsants, barbiturates, benzodiazepines, carbon monoxide, chloral hydrate, cyanide, cyclic antidepressants, hydrocarbons, hypoglycemics, insulin, lithium, narcotics, phenothiazines, salicylates, sedative-hypnotics, solvents

Seizures

Amphetamines, camphor, carbon monoxide, cocaine, gyromitra mushrooms, isoniazid, lead, lindane, nicotine, pesticides, phencyclidine, propoxyphene, salicylates, strychnine, theophylline, tricyclic antidepressants

Miosis

Narcotics, organophosphates, phenothiazines, phencyclidine

Mydriasis

Amphetamine, anticholinergics, antihistamines, atropine, cocaine, phenylpropanolamine, tricyclic antidepressants

Nystagmus

Phencyclidine, phenytoin

Peripheral neuropathy

Acrylamide, carbon disulfide, heavy metals

 

Skin examination

Cyanosis suggests hypoxia secondary to aspiration (eg, hydrocarbon) or asphyxia.

Cardiovascular effects

Sympathetic stimulation can cause hypertension with tachycardia.

Hypotension is caused by beta adrenergic blockade, calcium channel blockade, sympatholytic agents, cellular toxins, psychopharmaceutical agents, disulfiram_ethanol, and shock associated with iron or arsenic.

Respiratory effects

Tachypnea and hyperpnea may result from salicylate poisoning. Nervous system stimulants.

Toxidromes

Common Toxidromes

Toxin ( Toxidrome)

Symptoms and Signs

Abstinence (narcotic withdrawal)

Shivering, nausea, vomiting, diarrhea, abdominal pain, lacrimation, diaphoresis, rhinorrhea, mydriasis, tremor, irritability, lethargy, yawning, delirium, seizures

Anticholinergic

Fever, flushing, dry skin, mydriasis, dry mouth, delirium

Cholinergic

Salivation, lacrimation, sweating, bronchorrhea, emesis, incontinence, diarrhea, miosis, muscle weakness, seizures, coma, fasciculation, myoclonus, wheezing, respiratory failure, bradycardia

Iron

Shock, fever, hyperglycemia, hemorrhagic diarrhea

Isoniazid

Seizures, coma, acidosis

Opiates

Coma, respiratory failure, pinpoint pupils

Phenothiazines

Dystonia syndrome, oculogyric crisis, hyperthermia syndrome, coma, prolonged QTc interval

Phencyclidine

Catatonia, rotatory nystagmus, seizures, aggressive paranoia

Salicylates

Fever, hyperpnea, tachypnea, tinnitus, acidosis, seizures

Tricyclic antidepressants

Seizures, coma, acidosis, tachyarrhythmia, prolonged QRS interval, hypotension

 

 

Diagnostic trials

For a few poisons, a "diagnostic trial" of an antidote can implicate an agent as the cause of a poisoning.

 

Diagnostic Trials

Toxin

Diagnostic Trial

Route

Positive Response

Benzodiazepine

Flumazenil 0.02 mg/kg

IV

Consciousness improves

Digitalis

Specific Fab antibodies

IV

Dysrhythmia resolves,

hyperkalemia improves,

consciousness improves

Insulin

Glucose 1 g/kg

IV

Consciousness improves

Iron

Deferoxamine 40 mg/kg

IM

Pink "vin rose" urine

Isoniazid

Pyridoxine 5 g

IV

Seizures abate

Opiate

Naloxone 0.1 mg/kg

IV

Consciousness improves

Phenothiazine

Diphenhydramine 1 mg/kg

IV

Dystonia and torticollis resolve

 

Management

Poison centers can help with the diagnosis and management of poisonings, and assist in locating exotic antidotes.

Initial management of poisoning involves maintaining an airway, providing ventilatory support, securing vascular access, and initiating resuscitation.

Decontamination

Skin, mucous membrane, or eye exposures should be washed with a stream of lukewarm water for 15 to 20 minutes. Soap is used to decontaminate skin exposures.

Emesis is most effective when less than 1 hour has elapsed since the ingestion; it can remove.

Antidotes

 

Childhood Antidotes

Toxin

Antidote

Acetaminophen

N-Acetylcysteine

Arsenic

BAL, Penicillamine

Benzodiazepine

Flumazenil

Carbon monoxide

Hyperbaric oxygen

Coumadin

Vitamin K1

Cyanide

Sodium nitrite/thiosulfate

Digitalis

Specific Fab antibody fragments

Ethylene glycol/ methanol

Ethanol (4-methylpyrazole)

Heparin

Protamine sulfate

Iron

Deferoxamine

Isoniazid

Pyridoxine

Lead

EDTA, Penicillamine, BAL, DMSA

Mercury

BAL

Narcotics

Naloxone

Organophosphate pesticides

Atropine/pralidoxime

Phenothiazines

Diphenhydramine

 

Specific toxins

Acetaminophen (APAP)

Single overdoses of greater than 150 mg/kg can cause liver failure. Nausea and abdominal pain are common. The patient may vomit repeatedly, be mildly lethargic, or remain asymptomatic. At 24 to 36 hours after the ingestion, abdominal tenderness and rising serum transaminase levels signify onset of

Alcohols

Alcohols include ethanol, ethylene glycol, methanol, and isopropyl alcohol.

Antifreeze contains ethylene glycol, Sterno and windshield wiper fluid contain methanol, jewelry cleaners and rubbing alcohol contain isopropanol.

All of the alcohols cause inebriation, loss of motor control and coma. Ethylene glycol may cause

Caustics

Drain cleaners contain sodium hydroxide or sulfuric acid; toilet cleaners may contain hydrochloric or sulfuric acids.

Laundry or dishwasher detergents may contain sodium metasilicate or sodium triphosphate.

Signs of caustic ingestion include lip or tongue swelling; burning pain; dysphagia; drooling; and whitish

Foreign body ingestion

Aspirated objects will cause symptoms of choking, gasping, coughing, cyanosis, wheezing, fever, and poor air entry. While chest radiography can confirm the diagnosis, a negative film does not rule out aspiration. A foreign body requires immediate removal by bronchoscopy.

Ingestion of disc batteries requires removal when lodged in the esophagus; those in the stomach or beyond should be followed with repeated abdominal films every 2 to 3 days to ensure passage. Disc batteries that have remained in one position for more than 7 days may require surgical removal. Coins or 

Hydrocarbons

Aliphatic hydrocarbons include kerosene, mineral oil, gasoline, and petrolatum. Kerosene and gasoline are capable of causing an aspiration pneumonia and CNS depression. Petrolatum, mineral oil and motor oil do not carry significant risk of injury. Aliphatic hydrocarbons in small doses are not

Aromatic hydrocarbons, such as xylene or toluene, are toxic. Aromatic hydrocarbon ingestions necessitate lavage because of their potent toxicities.

Aspiration pneumonia is suggested by gasping, choking, coughing, chest pain, dyspnea, cyanosis,

Iron

Iron is present in many children's multivitamins, although the worst cases of iron poisoning usually involve prenatal vitamins, which contain 60 mg of elemental iron per tablet. In overdose, iron is a metabolic poison and is corrosive to gastric mucosa, resulting in shock.

Ferrous sulfate is 20% elemental iron, ferrous fumarate 33%, and ferrous gluconate 11%. Little toxicity is seen at a dose of elemental iron less than 20 mg/kg. Mild symptoms of poisoning are seen at doses of.

Salicylates

Aspirin overdoses greater than 150 mg/kg are toxic. Salicylates are locally corrosive, and tablets can form bezoars near the gastric outlet. Salicylates stimulate the central respiratory center, so that the