title: [Hemoglobin-based blood substitutes: current status and perspectives].
abstract: OBJECTIVE
  Alternatives to red blood cells transfusion have been studied since the fifties. This study aimed at presenting current status and perspectives of hemoglobin-based blood substitutes.
  
  
  BACKGROUND
  Potential application areas are presented, in addition to clinical studies involving major hemoglobin molecules developed, their advantages and limitations.
  
  
  CONCLUSIONS
  Several randomized trials have shown efficacy in avoiding or decreasing red blood cells transfusions, however there are some limitations and the future blood substitute shall at least have the same safety and efficacy of blood itself.
authors.affiliation: Universidade Federal do Paraná, Brazil. tanaka@bsi.com.br
authors.forename: Pedro Paulo
authors.initials: PP
authors.lastname: Tanaka
authors.forename: Maria Aparecida Almeida
authors.initials: MA
authors.lastname: Tanaka