Iron Toxicity Quiz

Historically, prenatal multivitamins are the most significant source of pediatric iron exposure. This makes sense if you consider that many women who are pregnant or preparing for pregnancy may have other small children in the house. Furthermore, the majority of prenatal multivitamins contain iron. The other answers are incorrect because (a) most children do not have access to industrial iron pellets for smelting, (b) ball bearings are stainless steel (iron+chromium+molybdenum+trace carbon) and likely would not result in significant absorption of iron, (c) adult multivitamins do not usually contain iron, and (e) children are more likely to have exploratory ingestions with prenatal multivitamins than they are with herbal preparations.

Iron absorption predominantly occurs in the duodenum. In fact, the human body has difficulty excreting Iron, so Iron homeostasis is maintained by regulation of absorption. All of the other answers are incorrect.

The correct answer is 33%. Ferrous gluconate containts 12%. Ferrous Sulfate contains 20%. A mnemonic to remember this is GSF 10-20-30.

Despite the diversity of Iron supplementation tablets, the majority of formulations have a Tmax around 4-6 hours. All of the other answers are incorrect.

The correct answer is that this is a potentially toxic dose of elemental Iron because the dose is greater than 60 mg/kg of elemental Iron. The patient took 21000 mg Ferrous Fumarate, which equates to approximately 7000 mg elemental iron. This means the patients dose is 70 mg/kg. The first answer is incorrect because the cutoff is 60 mg/kg. The other answers are incorrect because the math is incorrect and the cutoffs are incorrect.

Out of all the answer choice, the only incorrect one is the last one. Exposure to Iron does not induce methemoglobinemia. All of the answer choices have been reported to be putative mechanisms for iron toxicity. Furthermore, the profound effect on the production of ROS likely explains the local toxicity to GI mucosa. Nonetheless, elevated tissue Iron levels have been found across multiple organ systems in fatal Iron overdose.

At this point, the patient states they have a relatively toxic and potentially fatal ingestion of iron. Treatment with defoxamine is indicated. If the patient has retained fragments on KUB, whole bowel irrigation is the recommended treatment. Elective intubation poses its own risks and can exacerbate acidosis if present. MDAC has no proven efficacy for metal ingestions. The last answer is incorrect because treatment should be initiated prior to development of toxicity, especially because the patient seems to be a reliable historian.

Administration of deferoxamine theraphy can increase the probability of infection with siderophoric bacteria, especially in critically ill patients. The most likely pathogen in this scenario is Yersinia Enterocolitica, which has been reported to cause bacteremia/sepsis in patients after receiving deferoxamine therapy. IV ceftriaxone is the indicated treatment as per Sanford Guide. The first answer is incorrect because organic etiologies for that patients decompensation should be considered first. Although C. Diff infection may seem likely, the patient has not received antibiotics prior to the case vignette, which makes C. Diff infection unlikely. Furthermore, the patient has been extubated for 4 days and doing well off the ventilator, which indicates VAP is less likely. Finally, there are no indications that the patient has a source for gram negative bacteremia (eg no indwelling foley or evidence of uti), so gram negative bacteremia is unlikely. Furthermore, current evidence suggests that vancomycin and piperacillin/tazobactam (zosyn) is typically not an appropriate choice for any patient due to the increased probability of acute kidney injury due to the combination of these xenobiotics.

In this case, the patient should be developing the first signs of iron toxicity, which mainly include GI upset. If labs are unremarkable for coingestion and the patient remains asymptomatmic at 6 hours after presentation, he is medically cleared for a psychiatric evaluation. KUB is not routinely indicated in asymptomatic Iron ingestions due to the low sensitivity and low specificity of the test. However, in symptomatic patients, a positive KUB for radioopaque tablets can guide management for advanced GI dicontamination. Activated charcoal has no role in the management of acute iron toxicity because it does not adequately sequester metal cations.

In this case, the patient is clearly Iron toxic. He is acidotic and has an elevated Iron level beyond 500 mcg/dL. Therefore he needs chelation therapy with deferoxamine AND supportive care. The patient is clearly Iron toxic due to acidosis, so only supportive care would be inappropriate. Furthermore, correcting this acidosis with sodium bicarb does not address the true etiology of his presentation. His tachycardia is likely a result of Iron toxicity and not due to alcohol withdrawal. Although, a trial of benzodiazepines for alcohol withdrawal would not be inappropriate, it is certainly not the definitive answer given a significantly elevated Iron level. Finally, the patient does not seem as if they will rapidly deteriorate to the point of intubation, so this answer is not correct.

In the critically-ill, Iron-poisoned patient, the patient needs to be clinically stabilized AND have normalization of urine color prior to cessation of deferoxamine therapy. While deferoxamine therapy is ongoing, chelated Iron will be excreted into the urine, causing the urine to be  reddish in color. As more Iron is cleared from the system the urine will return to the normal yellow/clear color.  Note that deferoxamine typically is only excreted in the urine in massive overdoses.

This patient has a reliable and significant reported Iron overdose. It is especially important to treat because Iron toxicity can have a profound effect on the fetus. Furthermore, deferoximine is pregnancy category C medication so treatment in this case likely outweighs the risk of non-treatment. This is especially important if you consider the fact that many medications are not tested for pregnancy safety due to rarity of necessity. Supportive care would be inappropriate because that does not adequately treat the patient for her reported ingestion. One option would be to wait for an Iron level; however, this is frequently not available even in the tertiary care centers. Monitoring for 6 hours to pend psychiatric clearance is inappropriate because it dose not address significant toxicologic risk. Discharge to close psychiatrist follow up is absolutely contraindicated in the setting of an acute suicide attempt. Similarly, discharge to close obstetrician follow-up is even more inappropriate because it does nothing to address the acute suicidality of the patient.