iron overload (iron poisoning)
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Etiology
- transfusion associated
- congenital hemolytic anemia
- long-standing aplastic anemia
- surreptitious ingestion
Pathology
- iron-induced organ toxicity may be seen when > 500 mL/kg of total packed erythrocytes are admministered (1 unit is about 300 mL with hematocrit of 70-80%)
- endocrine disturbances, including diabetes mellitus
- cirrhosis
- growth retardation
- cardiac toxicity (may be fatal)
Genetics
- mutations in SLC11A2 are associated with progressive liver iron overload & normal to moderately elevated serum ferritin levels
Clinical manifestations
- hemorrhagic GI symptoms within 6 hours of ingestion
- symptoms may improve 6-12 hours after ingestion with supportive care
- systemic toxicity may occur 12-24 hours after ingestion
Laboratory
Complications
- multiorgan failure
- metabolic acidosis
- liver injury
- hypovolemia or shock
- altered mental status
- seizures
- increased risk of bone fractures, especially vertebral fractures & humerus fractures[6]
Management
- transfusion-related iron overload:
- iron chelation therapy (deferoxamine) when transferrin becomes fully saturated or evidence of iron-induced tissue damage[1]
- therapeutic phlebotomy contraindicated patient is anemic
- deferiprone or deferasirox oral chelating agents may be more convenient than deferoxamine infusion
- ingestion of iron: (also see poisoning)
- ingestion of > 20 mg/kg of elemental iron generally needs active management
- gastric decontamination
- ipecac
- within 30-45 minutes of ingestion (not effective)[2]
- contraindications include: ingestion of caustic agents, hydrocarbons, drugs known to cause abrupt loss of consciousness or seizures, foreign bodies, non-toxic substances; unconscious patients, patients with seizures, inability to protect airway (intubated patients)[2]; patients with intentional ingestion
- gastric lavage
- performed prior to administration of charcoal
- activated charcoal not recommended[2]
- 34-40 French orogastric tube (adults)
- 150-200 mL aliquots of warm water or normal saline
- 5-10 liters total
- ipecac
- whole bowel irrigation
- polyethylene glycol-electrolyte lavage solution
- dosage:
- most effective means of GI decontamination
- iron chelation therapy (deferoxamine)
- if systemic manifestations or serum iron > 500 ug/dL
- ingestion of > 20 mg/kg of elemental iron[2]
- GI decontamination not recommented if pills have already been absorbed or if liquid iron solutions were ingested[2]
- also see hemochromatosis
- AVOID vitamin C supplements
More general terms
Additional terms
References
- ↑ Jump up to: 1.0 1.1 Medical Knowledge Self Assessment Program (MKSAP) 11, 15, 16, 17, 18. American College of Physicians, Philadelphia 1998, 2009, 2012, 2015, 2018.
- ↑ Jump up to: 2.0 2.1 2.2 2.3 2.4 2.5 NEJM Knowledge+ Question of the Week. Aug 21, 2018 https://knowledgeplus.nejm.org/question-of-week/4149/
- ↑ Madiwale T, Liebelt E. Iron: not a benign therapeutic drug. Curr Opin Pediatr 2006 Apr 8; 18:17 PMID: https://www.ncbi.nlm.nih.gov/pubmed/1660149
- ↑ Chang TP, Rangan C. Iron poisoning: a literature-based review of epidemiology, diagnosis, and management. Pediatr Emerg Care 2011 Oct; 27:978 PMID: https://www.ncbi.nlm.nih.gov/pubmed/21975503
- ↑ Manoguerra AS, Erdman AR, Booze LL et al. Iron ingestion: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila) 2005; 43:553 PMID: https://www.ncbi.nlm.nih.gov/pubmed/16255338
- ↑ Jump up to: 6.0 6.1 Choudhury J Iron Overload: The Silent Bone Breaker Medscape. Dec 4, 2024 https://www.medscape.com/viewarticle/iron-overload-silent-bone-breaker-2024a1000m4f