4 The radiopacity of Fe varies with the preparation, time since ingestion, and amount of ingestion. Total iron binding capacity (TIBC), glucose, and WBC counts are unreliable in predicting iron toxicity. 1 Additional lab tests to consider obtaining include: After 6 hours, Fe distributes out of the intravascular compartment, and levels are less useful for predicting toxicity. 2 Laboratory Testingįor most preparations, a peak Fe level occurs 2–6 hours post-ingestion. The peak level predicts severity of iron toxicity and guides management decisions (see table below). If no vomiting has occurred within 6 hours after ingestion, then the patient likely did not ingest a toxic dose. This patient can be medically cleared. The lack of vomiting early after an ingestion (during stage I) has important clinical significance. Sequelae: Gastric outlet obstruction, small bowel obstruction
Shock, acidosis, coagulopathy, coma, multisystem organ failure Latent toxicity: Resolution of local toxicity with ongoing cellular toxicity, hypovolemia, poor tissue perfusion (metabolic acidosis, ↑ lactate levels) Local toxicity: Nausea, vomiting, diarrhea abdominal pain, gastrointestinal bleeding
IRON TOXICITY ANTIDOTE FREE
Engages in redox reactions with the formation of free radicals and oxidative damageĬlassically, five stages of iron toxicity are described (adapted from 4): Stage.Iron causes toxicity thru several mechanisms, including 3: Once transferrin is saturated, “free” Fe is available to cause toxicity. In Fe overdoses, the corrosive effects of Fe on the GI tract mucosa permit passive absorption of Fe. It is then disposed of via epithelial cell shedding or, depending on the body’s need, can be released to transferrin, a serum Fe-binding protein. Absorption occurs in the duodenum, where Fe is stored as ferritin in the intestinal cells. Total body Fe is regulated via absorption from the gastrointestinal tract. ≥40 mg/kg Current level recommended for ED referral after ingestion 2.>20 mg/kg Gastrointestinal symptoms start.The total elemental Fe ingested is: (65 mg/tab x 80 tablets) /50 kg = 104 mg/kg. For example, the elemental iron equivalent calculation for 80 tablets of Ferrous Sulfate is: 325 mg Fe/tablet x 20% elemental Fe/tablet = 65 mg elemental Fe/tablet. Multiply the total Fe content in each tablet by the percentage of elemental Fe for the product formulation. Examples of Fe formulations and the amount of elemental Fe contained in each formulation are listed in the table below (adapted from 1).Ĭalculating amount of elemental Fe ingested Iron toxicity is determined by the amount of elemental iron (Fe) ingested.
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