A 2 years old child ,13 kg ,brought to ED after ingesting unknown amount of the below syrup.It happened 1 hour back.
He had vomited once,otherwise normal vitals and examination.
Q1.What is the toxic dose and expected toxicity?
Q2.How will you manage this child?
Iron Baby Cont'
Iron supplements are available as the iron salts ferrous gluconate, ferrous
sulfate, and ferrous fumarate and as the nonionic preparations carbonyl
iron and polysaccharide iron.
Toxic effects of iron poisoning occur at doses of 10 to 20 mg/kg of elemental
iron, which is defined as the amount of iron ion present in an iron salt
Significant GI toxic effects 20 mg-40 mg /kg elemental iron. Severe systemic toxicity is seen at levels above 60 mg/kg
Clinical stages of iron toxicity
The first stage of iron toxicity is characterized by local toxic effects of iron , including nausea, vomiting, abdominal pain, and diarrhea. Later on Intestinal ulceration, edema, transmural inflammation, small-bowel infarction and necrosis occur. They can have Hematemesis, melena, or hematochezia contribute to hemodynamic instability.
The absence of GI signs and symptoms, specifically vomiting, in the first 6 hours after ingestion, almost always excludes serious iron toxicity.
The second, or “latent,” stage of iron poisoning commonly refers to the period 6 to 24 hours after ingestion when resolution of GI symptoms and findings occurs but overt systemic toxicity has not yet developed.
This second stage is not truly quiescent because cellular toxicity continues.
Patients in the latent phase generally have lethargy, tachycardia, or metabolic acidosis. They should be readily identifiable as clinically ill despite resolution of their GI symptoms.
Patients who have remained well since ingestion and who have stable vital signs, a normal mental status, and a normal acid–base balance will have a benign clinical course.
The third, or “shock,” stage of iron poisoning have profound toxicity. This stage typically occurs in the first few hours after a massive (>60 mg/kg elemental iron) ingestion or as long as 12 to 24 hours after a more moderate (>40 mg/kg) ingestion.
The cause of shock is likely multifactorial, resulting from one or more of these pathologic processes: hypovolemia, vasodilation, and poor cardiac output, decreased tissue perfusion and a metabolic acidosis. Iron-induced coagulopathy worsens bleeding and hypovolemia.
Systemic toxicity produces central nervous system effects such as lethargy, hyperventilation, seizures, or coma.
The fourth stage of iron poisoning is characterized by hepatic failure, which typically occurs 2 to 3 days after ingestion. The hepatotoxicity is directly attributed to iron uptake by the reticuloendothelial system in the liver, where it causes oxidative damage.
The fifth stage of iron toxicity is rarely manifest. Gastric outlet obstruction, secondary to strictures and scarring from the initial GI injury, develops 2 to 8 weeks after ingestion.
Management (Refer to Figure )
Labs:
laboratory studies are used as surrogate markers to assess the severity of iron poisoning. An anion gap metabolic acidosis and an elevated lactate concentration will develop in patients with serious iron ingestions. Serial blood counts and electrolyte measurements should be used to assess progression and response to volume replacement.
significant GI toxicity, patient who required IV fluid resuscitation had peak serum iron concentrations in the range of 300 mcg/dL between 2 and 4 hours after ingestion. Serum iron concentrations between 300 and 500 mcg/dL usually correlate with significant GI toxicity and modest systemic toxicity. Concentrations between 500 and 1,000 mcg/dL are associated with pronounced systemic toxicity and shock.
Abdominal radiograph :Iron is available in many forms, and the different preparations vary with respect to radiopacity, plus other factors such as the time since ingestion and elemental iron content of the tablets .Iron does not get adsorbed by Activated charcoal and whole bowel irrigation ( WBI) is the modality of GI decontamination
The usual dose of WBI with polyethylene glycol electrolyte lavage solution (PEG-ELS) is 500 mL/h in children and 2 L/h in adults. This rate is best achieved by starting slowly and increasing as tolerated
Deferoxamine is recommended for iron-poisoned patients with any of the following findings: repetitive vomiting, toxic appearance, hypotension accompanied by metabolic acidosis or signs of shock, and any patients with serum iron concentrations above 500 mcg/dL
Dose is initiated as an IV infusion, starting at 5 mg/kg/h and gradually increasing to a rate of 15 mg/kg/h. Hypotension is the rate-limiting factor as more rapid infusions are used.34 After several hours of infusion at 15 mg/kg/h, the patient should be reassessed and the dose decreased to keep the maximum dose less than 6 to 8 g/24 hours.
References:
Goldfrank’s Toxicologic Emergencies 11th edition