Magnetic foreign body injuries: a large pediatric hospital experience.
OBJECTIVE
To examine trends in magnet-related injuries and hypothesize that changes are a result of new neodymium-iron-boron magnets that are smaller, stronger, and commonly sold in sets.


METHODS
In this retrospective chart review, we searched our institution's electronic patient record for patients less than 18 years old who were diagnosed with magnetic foreign body ingestion between 2002 and 2012. Cases were analyzed for patient, magnetic foreign body, and management characteristics. Incidence rates and case characteristics were compared between the first 8 years of the study period and the last 3.


RESULTS
We identified 94 patients who met our search criteria. Of confirmed ingestions, the median age was 4.5 years and 65% were male. The incidence of visits increased between the 2002-2009 period and the 2010-2012 period by a factor of 2.94 (95% CI, 1.84-4.70), whereas the incidence of injuries involving multiple magnets increased by a factor of 8.40 (95% CI, 3.44-20.56). The volume of the magnets decreased from 878.6 mm3 to 259.8 mm3. Six cases required surgical removal of the magnets because of intra-abdominal sepsis or concern for imminent bowel perforation.


CONCLUSIONS
Since 2002, there has been a significant increase in the incidence of magnetic foreign body injuries. These injuries have increasingly involved multiple, smaller magnets and required operative intervention.
Hospital for Sick Children, Toronto, Ontario, Canada; Division of General Surgery, University of Toronto, Toronto, Ontario, Canada. Electronic address: matt.strickland@utoronto.ca.
Matt
M
Strickland
Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
Daniel
D
Rosenfield
Hospital for Sick Children, Toronto, Ontario, Canada; Division of General Surgery, University of Toronto, Toronto, Ontario, Canada.
Annie
A
Fecteau
D000293:Adolescent; D001895:Boron; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D057286:Electronic Health Records; D004636:Emergency Service, Hospital; D005260:Female; D005547:Foreign Bodies / Q000453:epidemiology*; D005767:Gastrointestinal Diseases / Q000453:epidemiology* / Q000209:etiology; D041981:Gastrointestinal Tract / Q000293:injuries*; D006776:Hospitals, Pediatric / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D007501:Iron; D059346:Magnets / Q000009:adverse effects*; D008297:Male; D009354:Neodymium; D010988:Play and Playthings / Q000293:injuries*; D012189:Retrospective Studies
D009354:Neodymium; D007501:Iron; D001895:Boron