Emergency Medicine Review Question of the Day

Iron toxicity has classically been described as having 5 phases. Phase 1 is the acute gastrointestinal (GI) phase as a result of the local direct effects of iron on the GI tract that are nearly universally present within 6 hours following an acute overdose. This is followed by phase 2, which begins 6-24 hours after ingestion and is sometimes called the latent phase because the GI symptoms improve. However, this period is hardly latent as systemic toxicity continues and other findings, such as metabolic acidosis or persistent tachycardia, may be present. Phase 3 is heralded by more overt signs of systemic toxicity such as hypotension, lactic acidosis, coagulopathy, azotemia, and depression of the central nervous system. Phase 4 occurs 2-3 days following ingestion with liver injury that may progress to liver failure. After recovery from a severe iron overdose, scaring and strictures of the GI tract may lead to late GI complications such as gastric outlet obstruction. These delayed GI complications have been classified as Phase 5.

It is important to recognize that any individual patient may not follow the classic time course here and evaluation and management should be predicated on clinical evaluation.

This patient has a completely benign evaluation at this time. Her ingestion history is either inaccurate or she "decontaminated" herself following the ingestion with emesis at home. A brief observation period is probably reasonable with further testing should any symptoms manifest. Otherwise, she may be medically cleared. An iron level is unlikely to be of benefit in this scenario.

References:
Howland MA. Deferoxamine. In: Nelson LS, et al. Goldfrank's Toxicologic Emergencies. 9th ed., 2010.
Liebelt EL. Iron. Shannon MW, et al. In: Haddad and Winchester's Clinical Management of Poisoning and Drug Overdose. 4th ed., 2007:1119-1128.
Perrone J. Iron. In: Nelson LS, et al. Goldfrank's Toxicologic Emergencies. 9th ed., 2010.