mitochondrial poison, particularly in the liver, with resulting changes in cellular energy metabolism and the production of metabolic acidosis Clinical Considerations The clinical effects of iron poisoning are classically divided into four phases Phase I represents the effects of direct mucosal injury and usually lasts hours Vomiting, diarrhea, and GI blood loss are the prominent early signs; when severe, the patient may lapse into early coma and shock caused by volume loss and metabolic acidosis Phase II, which lasts from to 24 hours after ingestion, is marked by diminution of the GI symptoms With appropriate therapy to replace fluid and/or blood losses, the child may seem relatively well and often goes on to full recovery without any subsequent symptoms However, this remission may be transient and may be followed by phase III, characterized by metabolic acidosis, coma, seizures, and intractable shock This phase is believed to represent hepatocellular injury with consequent disturbed energy metabolism; elevated levels of lactic and citric acids are noted in experimental iron poisoning before cardiac or respiratory failure occurs Jaundice and elevated transaminases are noted in this phase A phase IV has been described in survivors of severe iron poisoning, marked by pyloric or duodenal stenosis resulting from scarring and consequent obstruction Laboratory abnormalities often associated with severe iron intoxication include metabolic acidosis, leukocytosis, hyperglycemia, hyperbilirubinemia and increased liver enzymes, and a prolonged prothrombin time If fluid loss is significant, there will be hemoconcentration and elevated BUN Abdominal films may show radiopaque material in the stomach, but the absence of this finding does not indicate a trivial ingestion Patients who arrive with severe early symptoms, including vomiting, diarrhea, GI bleeding, depressed sensorium, or circulatory compromise merit urgent, intensive treatment in the ED The first priority is to obtain venous access Simultaneously, draw blood for CBC, blood glucose, electrolytes, BUN, liver function tests, serum iron, and type and cross-match analyses GI decontamination is begun as detailed in the following section Provide crystalloid to support blood pressure Start chelation therapy with IV deferoxamine immediately in all severely poisoned patients Obtain an abdominal radiograph as soon as possible after GI decontamination to determine its efficacy and to investigate for the presence of iron pill concretions