Toddler with a large elemental iron ingestion
A 2.5-year-old boy, weight 12 kg, is brought 3 hours after he was found playing with an open bottle of ferrous sulfate tablets. The mother estimates he swallowed about 20 tablets, each containing 325 mg ferrous sulfate (65 mg elemental iron). He vomited once, the vomit contained no blood, and he is now drowsy but rousable. Examination: heart rate 132/min, blood pressure 88/55 mmHg, respiratory rate 28/min, capillary refill 3 seconds, abdomen soft, no tenderness, no blood per rectum. An abdominal radiograph shows several radio-opaque tablets in the stomach. Serum iron results will not be available for 4 hours. The emergency department has deferoxamine, activated charcoal, and polyethylene glycol solution. The parents ask whether he needs his stomach pumped and whether charcoal will help.
1. Estimate the elemental iron dose in mg/kg and classify the risk. What decontamination would you consider, and why is activated charcoal not useful?
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The estimated elemental iron dose is 20 tablets × 65 mg = 1,300 mg. Divided by 12 kg, that is about 108 mg/kg. Ingestions above 60 mg/kg of elemental iron are potentially severe, and this child is well above that threshold. He is symptomatic with drowsiness and delayed capillary refill, which increases concern for systemic toxicity.
Decontamination:
- Activated charcoal does not bind iron and should not be used.
- Gastric lavage may be considered for a very large ingestion presenting within about 1 hour, but at 3 hours with tablets still in the stomach, it is unlikely to be effective and carries aspiration risk.
- Whole-bowel irrigation with polyethylene glycol solution can be considered for radiopaque tablets or sustained-release preparations, especially if tablets remain in the gastrointestinal tract. It should not be used if there is obstruction, ileus, or hemodynamic instability.
- Serial abdominal radiographs can help track tablet movement.
The reasoning is that iron is directly corrosive to the gastrointestinal mucosa and is absorbed systemically; charcoal has no affinity for it, so the therapeutic focus is limiting absorption and treating systemic toxicity.
2. What are the indications for deferoxamine, and how would you administer it? What monitoring is required?
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Deferoxamine is indicated when there is evidence of moderate to severe systemic iron toxicity, such as:
- Serum iron greater than 500 mcg/dL, if available.
- Metabolic acidosis, shock, altered mental status, or severe gastrointestinal symptoms.
- A suggestive history with a very large ingestion and clinical deterioration, even before the iron result returns.
Administration:
- Intravenous deferoxamine 15 mg/kg/hour is standard for severe poisoning. For this child, that is about 180 mg/hour.
- Continue until the patient is clinically stable and acidosis and shock have resolved; the duration should be guided by the clinical course and serial iron levels.
- Avoid rapid bolus administration, which can cause hypotension.
Monitoring:
- Blood pressure, heart rate, urine output, and mental status.
- Liver enzymes, coagulation, glucose, electrolytes, and blood gas.
- Watch for anaphylaxis, hypotension, and acute kidney injury. Urine color change is not a reliable endpoint. Deferoxamine can cause pulmonary toxicity with prolonged high-dose use, so the dose and duration should be minimized once the patient improves.
3. This child is drowsy with a lactate of 4.5 mmol/L and blood pressure 88/55. Outline disposition and the first 6 hours. Include when to discharge an asymptomatic child.
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This child is symptomatic with hypotension, delayed capillary refill, and lactic acidosis, so he requires admission to a monitored bed, ideally with pediatric critical care capability. The first 6 hours should include:
- Intravenous access, 0.9% saline boluses of 10–20 mL/kg titrated to perfusion, and careful reassessment for pulmonary edema.
- Intravenous deferoxamine if the criteria for systemic toxicity are met, without waiting for the serum iron if the clinical picture is severe.
- Serial blood gases, glucose, electrolytes, liver enzymes, coagulation, and complete blood count.
- Continuous cardiac and blood pressure monitoring; observe for gastrointestinal bleeding, hepatic failure, and shock.
- Consider whole-bowel irrigation if tablets remain and the airway is protected.
- Social and psychiatric assessment, because a toddler ingestion usually reflects inadequate supervision or unsafe storage.
Discharge of an asymptomatic child is reasonable only after at least 6 hours of observation with a normal physical examination, normal blood gas, normal glucose and electrolytes, and a low or falling serum iron level, with reliable follow-up and poison-center advice. This child does not meet discharge criteria.