title: Point-of-Care Versus Central Laboratory Measurements of Hemoglobin, Hematocrit, Glucose, Bicarbonate and Electrolytes: A Prospective Observational Study in Critically Ill Patients.
abstract: BACKGROUND
  Rapid detection of abnormal biological values using point-of-care (POC) testing allows clinicians to promptly initiate therapy; however, there are concerns regarding the reliability of POC measurements. We investigated the agreement between the latest generation blood gas analyzer and central laboratory measurements of electrolytes, bicarbonate, hemoglobin, hematocrit, and glucose.
  
  
  METHODS
  314 paired samples were collected prospectively from 51 critically ill patients. All samples were drawn simultaneously in the morning from an arterial line. BD Vacutainer tubes were analyzed in the central laboratory using Beckman Coulter analyzers (AU 5800 and DxH 800). BD Preset 3 ml heparinized-syringes were analyzed immediately in the ICU using the POC Siemens RAPIDPoint 500 blood gas system. We used CLIA proficiency testing criteria to define acceptable analytical performance and interchangeability.
  
  
  RESULTS
  Biases, limits of agreement (±1.96 SD) and coefficients of correlation were respectively: 1.3 (-2.2 to 4.8 mmol/L, r = 0.936) for sodium; 0.2 (-0.2 to 0.6 mmol/L, r = 0.944) for potassium; -0.9 (-3.7 to 2 mmol/L, r = 0.967) for chloride; 0.8 (-1.9 to 3.4 mmol/L, r = 0.968) for bicarbonate; -11 (-30 to 9 mg/dL, r = 0.972) for glucose; -0.8 (-1.4 to -0.2 g/dL, r = 0.985) for hemoglobin; and -1.1 (-2.9 to 0.7%, r = 0.981) for hematocrit. All differences were below CLIA cut-off values, except for hemoglobin.
  
  
  CONCLUSIONS
  Compared to central Laboratory analyzers, the POC Siemens RAPIDPoint 500 blood gas system satisfied the CLIA criteria of interchangeability for all tested parameters, except for hemoglobin. These results are warranted for our own procedures and devices. Bearing these restrictions, we recommend clinicians to initiate an appropriate therapy based on POC testing without awaiting a control measurement.
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Jérôme
authors.identifier: http://orcid.org/0000-0002-6464-2382
authors.initials: J
authors.lastname: Allardet-Servent
authors.affiliation: Laboratoire Européen, Laboratoire de Biologie Spécialisée Alphabio, Marseille, France.
authors.forename: Melissa
authors.initials: M
authors.lastname: Lebsir
authors.affiliation: Laboratoire Européen, Laboratoire de Biologie Spécialisée Alphabio, Marseille, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Dubroca
authors.affiliation: Laboratoire Européen, Laboratoire de Biologie Spécialisée Alphabio, Marseille, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Fabrigoule
authors.affiliation: Laboratoire Européen, Laboratoire de Biologie Spécialisée Alphabio, Marseille, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Jordana
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Signouret
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Matthias
authors.initials: M
authors.lastname: Castanier
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Guillemette
authors.initials: G
authors.lastname: Thomas
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Rettinavelou
authors.initials: R
authors.lastname: Soundaravelou
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Lepidi
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Delapierre
authors.affiliation: Laboratoire Européen, Laboratoire de Biologie Spécialisée Alphabio, Marseille, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Penaranda
authors.affiliation: Laboratoire Européen, Laboratoire de Biologie Spécialisée Alphabio, Marseille, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Halfon
authors.affiliation: Service de Réanimation, Hôpital Européen Marseille, Marseille, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Seghboyan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001639:Bicarbonates / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods / Q000592:standards; D001784:Blood Gas Analysis / Q000379:methods / Q000592:standards; D001786:Blood Glucose; D016638:Critical Illness; D004573:Electrolytes / Q000097:blood*; D005260:Female; D006400:Hematocrit / Q000379:methods; D006454:Hemoglobins; D006801:Humans; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D012016:Reference Values
chemical_list: D001639:Bicarbonates; D001786:Blood Glucose; D004573:Electrolytes; D006454:Hemoglobins