title: Reference values for methemoglobin concentrations in children.
abstract: OBJECTIVE
  The aim of this work was to establish reference values for methemoglobin levels in 6 to 10-year-old children.
  
  
  METHODS
  Methemoglobin concentrations were studied in clinically healthy children. The method for methemoglobin measurement used, neither uses highly toxic chemical compounds nor expensive enzymatic methods, thus it is feasible in the laboratory routine.
  
  
  RESULTS
  The results showed higher reference values for clinically healthy children (from 3.61 to 6.44%) than for adults (from 1.9 to 3.8%).
  
  
  CONCLUSIONS
  The higher concentrations of methemoglobin in children may be explained by smaller amounts of soluble cofactor cytochrome b5 and reduced activity of the cytochrome b5 reductase enzyme in red blood cells which make children particularly susceptible to the development of methemoglobinemia. Methemoglobin concentrations in children are higher than in normal adult subjects thus, adult reference values cannot be used to interpret infant methemoglobinemia.
authors.affiliation: Pharmaceutical Sciences, Universidade Federal do Paraná - UFPR, Curitiba, PR, Brazil.
authors.forename: Kely Francini
authors.initials: KF
authors.lastname: Rechetzki
authors.forename: Railson
authors.initials: R
authors.lastname: Henneberg
authors.forename: Paulo Henrique
authors.initials: PH
authors.lastname: da Silva
authors.forename: Aguinaldo José
authors.initials: AJ
authors.lastname: do Nascimento