title: Incidence of subclinical methemoglobinemia in infants with diarrhea.
abstract: OBJECTIVE
  Infants with diarrhea are at a greater-than-recognized risk of developing methemoglobinemia.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  A university hospital pediatric emergency department.
  
  
  METHODS
  Consecutive infants under 6 months of age with a history of diarrhea of more than 24 hours' duration not associated with vomiting.
  
  
  METHODS
  Blood samples were obtained for methemoglobin (MHgb) assay (normal, 0.4% to 1.5%) and electrolytes. Treatment interventions were performed as clinically indicated. Patients with elevated MHgb levels subsequently underwent hemoglobin electrophoresis to exclude congenital methemoglobinemia.
  
  
  RESULTS
  Forty-three patients were studied; 27 (64%) had elevated MHgb levels and 13 were cyanotic. Five patients received infusions of methylene blue for methemoglobinemia. All patients recovered without sequelae. There was a strong correlation between weight at or below the tenth percentile for age and the development of methemoglobinemia. Contrary to previous studies, there was no correlation between incidence or severity of methemoglobinemia and acidosis, hyperchloremia, or positive microbiologic studies.
  
  
  CONCLUSIONS
  In ill infants with diarrhea, particularly those who are small for age, consideration should be given to screening for methemoglobinemia.
authors.affiliation: Department of Emergency Medicine, Maricopa Medical Center, Phoenix, Arizona.
authors.forename: E S
authors.initials: ES
authors.lastname: Pollack
authors.forename: C V
authors.initials: CV
authors.lastname: Pollack
mesh_terms: D001797:Blood Protein Electrophoresis; D001835:Body Weight; D003968:Diarrhea, Infantile / Q000097:blood / Q000150:complications*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008706:Methemoglobin / Q000032:analysis; D008708:Methemoglobinemia / Q000097:blood / Q000188:drug therapy / Q000209:etiology*; D008751:Methylene Blue / Q000627:therapeutic use; D011446:Prospective Studies
chemical_list: D008706:Methemoglobin; D008751:Methylene Blue