Pediatric Toxicology

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Pediatric Toxicology

• Jay Fisher MD
• Pediatric Emergency Services
• University Medical Center

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Epidemiology

• 2.4 million events reported to U.S. poison
  centers annually
• 50 are in children lt 6 years.
• Less than 50 deaths annually.
• 10 Fold decrease in deaths since 1950

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Reason For Decrease Prevention

• Packaging legislation child resistant closures
• Safer medications (tetracyclic gt tricyclic)
• Consumer Product Safety measures
• Poison Centers 1-800-222-1222
• Anticipatory Guidance

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Clinical Approach - History

• Details are extremely important and will strongly
  impact management.
• Identify the potential poisons.
• Create an accurate time line.
• How long was the child unattended?
• Medications in the home, visitors?

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Symptoms and Physical Exam Toxidrome?

• Vomiting, diarrhea, lacrimation?
• Loss of conciousness, seizure, rash?
• Vital signs
• Mental status

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Anti-cholinergic Poisoning

• Red as a beet Diffuse erythema
• Dry as a bone Dry mucous membranes
• Mad as a hatter Confusion, psychosis, seizures
• Hot as Hades Temperature elevation,
  tachycardia, hypertension.
• Blind as a bat - Mydriasis, sluggish to light

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Cholinergic Excess - SLUDGE

• Salivation
• Lacrimation
• Urination
• Defecation
• Gastric Cramping
• Emesis

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Sympathomimetics

• Agitation, confusion, combative, convulsion
• Tachycardia, Hypertension, Elevated temperature
• Mydriasis, Reactive to Light
• Diaphoresis

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Opiates

• Euphoria, somnolence, unresponsive
• Pinpoint pupils
• Respiratory depression
• Bradycardia, hypotension
• Decreased body temperature

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Serotonin Syndrome

• Typically occurs with patients on multiple
  agents, particularly SSRIs
• Case reports of kids with SS after a single dose
  of some SSRIs.

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Serotonin Syndrome

• Autonomic instability, fever
• Confusion, seizures, agitation
• Increased tone in the lower extremities
• Myoclonus
• Reminiscent of Neuroleptic Malignant Syndrome

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NMS vs SS

• Higher fever
• Develops slower (days vs hours)
• Rigidity and bradykinesis as opposed to myoclonus
  and hyperkinesis
• More extra-pyramidal symptoms jaw stiffness,
  athetosis

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Clinical InterventionGastrointestinal
Decontamination

• Ipecac Never
• Gastric Lavage Rarely
• Activated Charcoal Infrequent
• Whole Bowel Irrigation Rarely
• Laparotomy Very Rarely

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Activate Charcoal A legitimate controversy
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Activated Charcoal An adsorbant.

• Burn wood, oxidize it at high temperatures with
  steam or CO2.
• Creates an internal trellis of pores with a
  surface area of 2 m2 per gram!
• Dose 1 g/ kg.
• Sorbitol additive is not necessary.

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Adult Volunteer Studies Reduction of Absorbed
Dose
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Am Ass. of Clin Tox Position Paper -2005

• There is no evidence charcoal improves clinical
  outcomes.
• Based on volunteer studies. Charcoal may be
  considered in high risk patients presenting
  within one hour of ingestion.

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Fleisher Ludwig - 2005

• Continues to recommend activated charcoal
  routinely in poisonings in which the patient
  presents to the ED and the toxin is still
  believed to be in the stomach.
• Still advocates multi-dose activated charcoal (GI
  dialysis) for certain poisons- theophylline,
  phenobarb, carbamazepine

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Activated Charcoal No Utility

• Alcohols
• Iron
• Lithium
• Caustics

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Activated Charcoal - Contraindications

• Patient with an unprotected airway.
• Caustics Vomiting may worsen esophageal injury
• Hydrocarbons Vomiting increases risk of
  aspiration pneumonitis.

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Activated Charcoal Why not?

• Labor intensive.
• Can often require naso-gastric tube placement to
  give a full dose.
• If patient decompensates, refluxing charcoal can
  be a big problem.
• Several case reports of aspiration pneumonia
  leading to death in children.

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Side Effects
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Poisonings What kills children?

• Hydrocarbons
• Cardiovascular drugs
• Narcotics
• Tri-cyclic antidepressants
• Industrial Chemicals
• Envenomations
• Anti-convulsants

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When a Pill can Kill

• Calcium Channel Blockers
• Clonidine/ Other Imidazoles
• TCAs
• Theophylline
• Sulfonylureas
• Diphenoxylate (Lomotil)
• Camphor and Methylsalicylate

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Antidotes

• Desferoxamine
• Sodium Bicarbonate
• Calcium Chloride/ Gluconate
• Methylene Blue
• Octreatide
• Pralidoxime
• Vitamin K

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Cases In Our Own Backyard
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18 mos old female brought by EMS with AMS

• No history of trauma
• No infectious prodrome
• No history of toxic exposures

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Physical Exam

• Temperature 99
• HR 240
• RR 26
• BP 121/76
• Alternating horizontal vertical nystagmus
• Extensor posturing

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PE - continued

• Abdomen distended, soft.
• Skin- upper face and trunk bright red
• Pupils 5 mm and reactive

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Case Progression

• Child requires benzodiapines, intubation,
  mechanical ventilation and bicarb.
• Blood serology returns positive for
  amitriptyline, which a visiting grandparent is
  taking.
• No further arrythmias develop.
• Patients discharged without sequelae several days
  later.

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2.5 yo female with lethargy

• Sudden onset of decreased responsiveness
  describe.
• No toxic exposures noted.
• No vomiting, no rash.
• No past medical history

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Acute AMS
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15 yo female with Celexa overdose

• Patient is on Celexa chronically for depression.
• Patient has a history of overdose in the past.
• Ingestion occurred two hours ago.
• Mother is forcefully demanding immediate
  intervention!

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Physical Exam

• Nursing assessment Patient will not cooperate
  with assessment.
• Vitals T 96.9/ HR 144/ RR 23/ BP
  167/71/ sat 100 on RA
• Eyes closed but would open to command.
• Answers questions appropriately.
• Hyperventilating intermittently.
• Intermittent myoclonus.

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Case Progression

• During discussion of the risks and benefits of
  gastric emptying with the mother, the patient
  starts seizing, loses her airway, and requires
  intubation.
• The patients seizures are treated with
  lorazepam.
• Patient is transferred to Monte Vista several
  days later without sequelae.

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15 yo arguing with boyfriend

• Ingested an ounce of rubbing alcohol to get a
  buzz after arguing with boyfriend.
• Vomited shortly after ingestion.
• Known to be an abuser of ethanol and marijuana.
• Denies suicidal intent or ideation.

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Physical Exam

• Awake, alert, cooperative.
• Vitals T 98/ HR 102/ RR 18/ BP 120/72
• Negative remainder of physical exam.

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Case Progression

• Child is discharged to follow-up with PMD in a
  couple of days.
• Vomiting and abdominal pain worsens over the next
  six hours.
• Patient returns to ED and admits to taking 30
  acetaminophen tablets with the rubbing alcohol 8
  hours ago.
• 8 hour level 140 mcg/ml

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Acetaminophen Overdose

• Most common agent ingested by teenagers during
  suicide.
• Overdose very well tolerated by young children.
• Over 150 mg/kg in a child, 10 to 15 grams in an
  adult can cause toxicity.
• N-Acetyl Cysteine eliminates toxicity if given
  within 8 hours of ingestion, reduces toxicity up
  to 16 hours after ingestion.

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APAP and Mucomyst

• APAP metabolized by three separate pathways.
• P450 pathway creates a toxic intermediate which
  usually is bound to glutathione and rendered
  harmless.
• With glutathione depleted, toxic intermediate
  induces hepatitis.
• NAC repletes glutathione