title: Rational use of blood calcium determinations.
abstract: OBJECTIVE
  This study was motivated by the recent excessive increase in requests for blood calcium determinations and laboratory tests in general, in the Hospital das Clínicas complex of Faculdade de Medicina, Universidade de São Paulo (HCFMUSP). Its aim was to suggest rules for the determination of total and ionized calcium in our intensive care units, emergency department, wards and outpatient services, thus contributing towards improving the quality of medical care and achieving more appropriate use of human and financial resources.
  
  
  METHODS
  Critical analysis on clinical and laboratory data and the pertinent scientific literature, conducted by the study group for rational clinical laboratory use, which is part of the Central Laboratory Division, HCFMUSP.
  
  
  METHODS
  The study group reviewed scientific publications, statistics and clinical and laboratory data concerning requests for total and ionized calcium determinations in the settings of intensive care units, emergency department, wards and outpatient services.
  
  
  RESULTS
  From this critical analysis, clinical decision flow diagrams aimed at providing guidance for ordering these tests were constructed.
  
  
  CONCLUSIONS
  Use of the proposed flow diagrams may help to limit the numbers of inappropriate requests for ionized and total calcium determinations, with consequent reductions in the number of tests, risks to patients and unnecessary costs.
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Mario
authors: M
authors: Ferreira-Junior
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Arnaldo
authors: A
authors: Lichtenstein
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Maria Mirtes
authors: MM
authors: Sales
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Leandro Utino
authors: LU
authors: Taniguchi
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Francisco José Bueno de
authors: FJ
authors: Aguiar
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Luiz Augusto Marcondes
authors: LA
authors: Fonseca
authors: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Nairo Massakazu
authors: NM
authors: Sumita
authors: Department of Pathology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors: Alberto José da Silva
authors: AJ
authors: Duarte
mesh_terms: D000465:Algorithms; D001938:Brazil; D002118:Calcium / Q000097:blood* / Q000502:physiology; D064790:Clinical Laboratory Services / Q000191:economics / Q000706:statistics & numerical data*; D003657:Decision Making; D006785:Hospitals, University; D006801:Humans; D011216:Practice Management, Medical / Q000191:economics / Q000592:standards*
chemical_list: D002118:Calcium