Levels drawn greater than 6 h after ingestion may underestimate toxicity due to ferritin binding and redistribtion of iron. Samples drawn too early or too late after ingestion may be unreliable. In adults, hyperglycemia, leukocytosis, abdominal pain and vomiting may be absent. It is important to follow glucose levels, since hepatic dysfunction may cause hypoglycemia. A CBC is also helpful since anemia due to blood loss may develop.
Coagulation studies are essential.
Following the prothrombin time may be helpful. Hepatic dysfunction is common in severe iron poisoning, since the liver is the first organ outside of the GI tract to encounter iron. Electrolytes and renal function tests allow calculation of the anion gap, electrolyte abnormalities and the presence of prerenal azotemia. Lipase and amylase levels may document occasional pancreatic injury. A pregnancy test should be performed for women of childbearing age.