title: Diabetic ketoacidosis: difference between potassium determined by blood gas analysis versus plasma measurement.
abstract: OBJECTIVE
  To evaluate the accuracy of potassium concentrations measured by blood gas analysis (PBG) compared with laboratory serum potassium (LSP), in the initial care of patients with diabetic ketoacidosis (DKA).
  
  
  METHODS
  Fifty three patients with diabetes mellitus were evaluated in a retrospective analysis. PBG was carried out using the Radiometer ABL 700 (Radiometer Copenhagen(®)), and results were compared with LSP ADVIA 1650 Chemistry system (Siemens(®)), the gold standard method. Both methods are based on potentiometry.
  
  
  RESULTS
  Mean PBG was 3.66 mmol/L and mean LSP was 4.79 mmol/L. Mean difference between PBG and LSP was -1.13 mmol/L (p < 0.0005, 95% CI, -1.39 to -0,86). Lin concordance correlation coefficient was rc = 0.28 (95% CIb, 0.10 to 0.45), demonstrating low concordance between the methods.
  
  
  CONCLUSIONS
  Although PBG measurement is faster and easier, it should not be used as a surrogate for LSP in the clinical treatment of DKA.
authors.affiliation: Departament of Endocrinology and Metabology, School of Medicine of São Jose do Rio Preto, SP, Brazil.
authors.forename: Fernando César
authors.initials: FC
authors.lastname: Robles
authors.forename: Daniel
authors.initials: D
authors.lastname: Laguna Neto
authors.forename: Fábio Guirado
authors.initials: FG
authors.lastname: Dias
authors.forename: Márcia
authors.initials: M
authors.lastname: Spressão
authors.forename: Priscila Nascimbeni
authors.initials: PN
authors.lastname: Matos
authors.forename: José Antônio
authors.initials: JA
authors.lastname: Cordeiro
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Pires
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis / Q000009:adverse effects / Q000379:methods; D001800:Blood Specimen Collection / Q000009:adverse effects / Q000379:methods; D016883:Diabetic Ketoacidosis / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood*; D011199:Potentiometry / Q000379:methods; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D011188:Potassium