Peds Poisonings

Author: Lilia Reyes, MD
Penn State Milton S. Hershey Medical Center
Department of Emergency Medicine
Division of Pediatric Emergency Medicine
Penn State College of Medicine

Editor: Matt Tews or Maggie Paik?

Objectives:

  • Describe the fundamental principles of the management of the acute overdose child
  • Define the differences between the toddler and the adolescent overdose patient
  • Choose the correct gastrointestinal decontamination procedure for the overdose patient
  • Identify when antidotes are indicated

Epidemiology:

Poisoning is one of the most common medical emergencies encountered by young children and also accounts for a significant number of emergency department (ED) visits in the adolescent age group.

Poisoning may be intentional or unintentional. Unintentional poisonings make up 80%-85% or more of all poisoning exposures in children.  Intentional poisoning is usually seen in adolescents and young adults, and comprises about 10-15%.

Among children 5 years of age and under, most exposures are due to exploratory behavior or willful child abuse.  Children between the ages of 1 to 4 years have increased finger-mouth activity and/or pica putting them at greater risk for accidental ingestion.  Male gender and a temperament that leans toward hyperactivity are also risk factors.  Ingestion is usually of a single agent and in a small amount. Morbidity and mortality is uncommon. Common ingestants in this age group are medications, consumer products, cleaning substances, and foreign bodies. Household cleaning products are the most common exposure in the younger (<5 yo) pediatric patient.  The most common pharmaceutical ingestions are analgesics and the most common fatal ingestions are from ethylene glycol, lithium, morphine, tramadol and disc batteries. The nine deadly pediatric poisons at small dosages are listed in table 1.  Ingestion in adolescent and young adults is often a suicidal gesture. Ingestion by an adolescent may involve many substances in larger amounts with morbidity and mortality being more likely. Ingestants are typically medications. The most common ingestion is acetaminophen and the most fatal ingestion is from cardiac active agents.

Table 1: Pediatric Poisonings that are Deadly at Small Dosages
Calcium channel blockers

Camphor, clonidine

Cyclic antidepressants

Opiates

Loperamide

Salicylates

Sulfonylureas

Toxic alcohols.

 

Initial Actions and Primary Survey

Evaluation of the poisoned child begins with the common ABC’s of resuscitation and stabilization. Assess airway, breathing and circulation.  If the patient is unstable then the history and physical will be done concurrently with the resuscitation.  The most common approach in the poisoned child/adolescent who has a decreased level of consciousness or abnormal vital signs is to address the few reversible causes for the symptoms presented. If there is hypoxia, place 100% oxygen via a nonrebreather. Patients with hypotension should be given crystalloid fluid boluses  (20 cc/kg) or a vasopressor agent if crystalloid fluid resuscitation fails to correct the hypotension.  If there is evidence of hypoglycemia from a finger stick blood glucose give intravenous dextrose (D10W 5cc/kg/dose) as needed. Consider giving naloxone 0.1mg/kg/dose IV (max 2mg) in the unresponsive patient with respiratory depression and suspected opiate ingestion, although some patients may require more than 2 mg total.

History

 It is important that you ask what medications are in the home, both prescription and over the counter. If able to identify what the substance is, you should ask at what time the ingestion happened, how much of the medication was in the container originally, how much medication was left at the time of presentation, and what symptoms the patient has had since ingestion.

Physical Examination

Vital signs

Level of consciousness

Pupils: miosis or mydriasis

Skin: color, presence of diaphoresis, dry skin or piloerection

Oral: moist/dry mucous membranes

Abdomen: hyper or hypoactive bowel sounds, bladder size (urinary retention)

Neurological: hypo or hyperreflexia, seizures

Differential Diagnosis

Toxidromes

Toxidromes are a set of sings and symptoms seen in specific poisonings.  These become clinically applicable in poisonings regardless of an available antidote.   Life saving antidote are available for opioids, tricyclic antidepressants, and cholinergic ingestions. Common toxidromes are listed in table 2 and specific antidotes for common agents are listed in table 3. 

Table 2: Common Toxidromes
  Opiate Sympathomimetic Anticholinergic Cholinergic Sedative-Hypnotic
Examples Heroin

Morphine

Clonidine

Cocaine

Amphetamines

Antihistamines

Tricyclic Antidepressants

Antipsychotics (not all)

Organophosphates

Nerve Agents Mushrooms (not all)

Benzodiazepines

Barbiturates

 

Mental Status Decreased Increased Increased Decreased Decreased
Pupils Miosis Mydriasis Mydriasis Miosis Miosis
VS:

HR

BP

RR

Temp

 

Bradycardia

Hypotension

Bradypnea

Apnea

Hypothermia

 

Tachycardia

Hypertension

 

 

Hyperthermia

 

Tachycardia

Hypertension

 

 

Hyperthermia

 

Bradycardia

 

Tachypnea

 

Hypothermia

 

 

Hypotension

Tachypnea

 

Hypothermia

Physical

Exam

  Tremor

Diaphoresis

Warm skin

Hyperactive Bowel Sounds

Hyperreflexia

Dry skin

Flushed skin

Urinary retention

Hypoactive bowel sounds

Salivation

Lacrimation

Urination

Defecation

Emesis

Bronchorrhea

Muscle Fasciculation

Diaphoresis

Hypoactive bowel sounds

Hyporeflexia

Antidote (not specific to a toxidrome but to a specific agent) Naloxone Benzodiazepine Physostigmine Atropine/

Pralidoxime

Supportive

  

Table 3: Common Agents and Antidotes

Agent Antidote
Acetaminophen N-acetylcysteine
Carbon Monoxide/Carboxyhemoglobin Oxygen

Hyperbaric Oxygen

Ethylene Glycol and Methanol

(not widely available, reference labs)

Fomepizole

Ethanol

Iron Deferoxamine
Lithium No specific agent

GI decontamination

Hemodialysis

Methemoglobin Methylene blue
Salicylates Urine alkalinization

 

Diagnostic Testing:

  • Urinary toxicology screen: is generally not helpful in the initial management of patients and are not standardized from one institution to another.
  • Electrocardiogram (EKG): specific findings in the QRS and

QT intervals, terminal R waves, and dysrhythmias can be helpful in diagnosis and management of an ingestion

  • Basic laboratory can be useful in identifying toxin because it may cause a characteristic abnormality. Patients with anion gap metabolic acidosis or an osmolar gap have a common differential diagnosis that should be evaluated as part of the work up (table 4 and 5)

 

Table 4: ANION GAP METABOLIC ACIDOSIS

M Methanol
U Uremia
D DKA
P Paraldehyde
I Iron, Isoniazid
L Lactic Acid
E Ethylene Glycol
S Salicylate

 Anion gap= (Na+  – [Cl¯ + HCO3]), normal 8-12

  

Table 5: Osmolar Gap

Ethanol Lactic Acidosis
Isopropanol Alcoholic ketoacidosis
Methanol Renal Failure
Ethylene Glycol Ethyl Ether
Acetone  
Paraldehyde  

 Osmolar gap= (measured osmols-calculated osmols)

Calculated osmols= {(2Na) + (Glucose/18) + (BUN/2.8)}

 

Serum drug concentrations for certain agents have levels that correspond to toxicity and have specific antidotes. Acetaminophen and salicylates should be screened for in most cases of ingestions.  Utility of the serum concentration is dependent on clinical correlation as well as other factors including timing of ingestion, mechanism of action, duration of effect, toxicokinetics and toxicodynamics.  Table 6 lists the drugs that have measurable toxicity levels and have a specific antidote.

 

Table 6: Drugs with measurable laboratory levels

Acetaminophen Lithium
Carbon Monoxide/Carboxyhemoglobin Methanol
Ethylene Glycol Methemoglobin
Iron Salicylates

 

 Treatment:

The management of the poisoned patient acutely should focus on supportive care (i.e. A, B, C’s). In specific situations enhancing elimination and/or specific antidotes may be indicated. Preventions of absorption can be accomplished by expelling toxin from above or below or via urinary alkalinization. Despite its widespread use, gastrointestinal decontamination has not been demonstrated to be beneficial and is generally indicated only in specific circumstances. Table7 lists mechanisms of decontamination.

 

Table 7: Mechanisms of Decontamination

Syrup of Ipecac  
Mechanism Plant extract that causes emesis
Indications NO LONGER RECOMMENDED
Contraindication Acids, alkalis, hydrocarbons, unprotected airway, depressed level of consciousness, seizure, cardio-pulmonary instability
Complications Aspiration, esophageal rupture, protracted vomiting

 

Orogastric Lavage  
Mechanism Use of large bore OG tube: gastric irrigation to remove pill fragments
Indications NO LONGER RECOMMENDED by the American Academy of Clinical Toxicology
Contraindication Acids, alkalis, hydrocarbons, unprotected airway
Complications Aspiration, esophageal rupture

 

Activated Charcoal  
Mechanism Adsorption by charcoal prevents absorption of drug in the GI tract
Indications Ingestion of potential toxic amount of substance within 1 hour of presentation
Contraindication Absence of intact or protected airway, bowel obstruction/perforation. NOT absorbed by charcoal: acids/alkali, hydrocarbon, heavy metals (Lithium, Iron), cyanide, pesticides, solvents, and alcohols
Complications Aspiration
Dose 1gm/kg PO/NG (child), 50-100gm (adolescent/adult)  Recommended dosage can also be 10:1 ration of activated charcoal to poison ingested

 

Multidose Activated Charcoal  
Mechanism Uses GI tract as a dialysis membrane
Indications Agents with enterohepatic or enteroenteric circulation such as: carbamazepine, digoxin, valproic acid, phenobarbital, salicylates, and theophylline
Contraindications May not be indicated in digoxin ingestion.  Salicylate ingestion may require more than one dose but not multiple doses.

 

Cathartics (Sorbitol)  
Mechanism Hyperosmolar agent that increase stool output
Indications Little evidence to support its use and generally not an option for gastric decontamination.
Contraindication < 6yo
Complications Electrolyte abnormalities

 

Whole Bowel Irrigation  
Mechanism Large volumes of polyethylene glycol are used to flush GI tract without causing fluid/electrolyte abnormalities
Indications Useful for Iron, Lithium and sustained release/enteric-coated preparation
Contraindication Ileus, GI obstruction/perforation, colitis
Dose Child: 25 mL/kg/hr (max 400mL) ; Adolescent/Adult: 1-1.5L/hr

 

Ion Trapping

(Urinary Alkalinization)

 
Mechanism Alkalinizing the urine may enhance excretion of acids by using H+ ions. Thus, leaving the toxin in its ion form that decreases absorption and promotes excretion.
Indications Salicylate or phenobarbital ingestions
Complications Must maintain normokalemia. Hypokalemia will decrease the potassium/acid exchange in the kidneys.
Dose 1-2 mEq/kg NaHCO3 q3-4hrs, (goal urine pH: 7.0 – 8.0)

 

Hemodialysis  
Mechanism Direct removal of toxin from the blood and corrects metabolic derangements
Indications Use for toxins that are small, have low protein binding, and have a low volume of distribution. Failure of supportive care and antidotes.

(e.g. ethlyene glycol, lithium, methanol, phenobarbital, salicylates, and theophylline)

 

Summary:

In summary, this is the general approach to the management of the poisoned pediatric patient.

  1. Resuscitation:
  • Assess Airway and intubate if needed
  • Assess Breathing and maintain oxygenation/ventilation.
  • Give naloxone for respiratory depression due to suspected opiate intoxication.
  • Assess Circulation and maintain cardiopulmonary monitoring. Fluid resuscitate with crystalloid if in shock
  • Assess Disability (i.e. mental status, seizures). Check for hypoglycemia. Remove clothing and plastic bag it for patients with dermal exposures.
  • Assess Environment for possible child abuse, suicidal intent or substance abuse.
  1. Clinical Evaluation (History/Physical Exam) to determine likely substance/substance class
  2. Testing

  • Screen for acetaminophen, salicylates, and pregnancy in all ingestions.
  • Obtain CBC, BMP, blood gas, bedside blood glucose, and specific drug levels as indicated.
  • EKG: may show signs of toxicity
  • CXR: for respiratory depression (i.e. aspiration pneumonitis, pulmonary edema)
  • AXR: for suspected ingestion of Iron, enteric coated preparations, or heavy metal
  1. Administer specific antidotes as indicated

  2. Consider toxin elimination techniques

  3. Supportive Care

References:

  1. Bryant S, Singer J. Management of toxic exposure in children. Emerg Med Clin North Am 2003; 21:101.
  2. Emery, D, Singer J. Highly toxic ingestions for toddlers: when a pill can kill. Pediatr Emerg Med Rep 1998; 3:111.
  3. Henretig, FM: Special considerations in the poisoned pediatric patient. Emerg Clin North Am 12:549-567, 1994
  4. Michael JB, Sztajnkrycer MD. Deadly pediatric poisons: nince common agents that kill at low doses. Emerg Med Clin North Am. 2004 Nov;22(4): 1019-50
  5. Mowry JP, Spyker DA, Cantilen LR Jr, eta al. 2012 Annual Report of American Association of Poison
  6. Osterhoudt KC, Burns Ewald M, Shannon M, Henretig FM. Toxicologic emergencies. In: Textbook of Pediatric Emergency Medicine, 6th, Fleisher GR, Ludwig S, Henretig FM. (Eds), Lippincott Williams & Wilkins, Philadelphia 2010. p.1170.

 

 

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