title: Assessment of blood lactate: practical evaluation of the Biosen 5030 lactate analyzer.
abstract: OBJECTIVE
  The aim of this study was to assess the validity and reliability of the Biosen 5030 lactate analyzer compared with a YSI 2300 lactate analyzer and a Kodak Ektachem DTII in a practical laboratory study context.
  
  
  METHODS
  To assess validity, 144 triplicate capillarized blood samples, across a range of values, were analyzed using the three analyzers. To assess reliability a further 665 samples were repeat analyzed. Temporal stability was determined by the reanalysis of resting and maximal exercise blood samples, after a period of storage ranging from 7 to 20 h, at room temperature. To measure inter- and intra-investigator reliability, 20 resting samples were taken from three different subjects by different investigators and a coefficient of variation was determined.
  
  
  RESULTS
  There were strong relationships between the Biosen, the YSI (r2 = 0.97), and the Kodak Ektachem (r2 = 0.91). An analysis of Biosen compared with YSI revealed a positive bias of 0.37 mmol x L(-1) (95% limits of agreement, -0.85 to 1.59 mmol x L(-1)). The test-retest reliability correlation was significant (r2 = 0.99, P < 0.05), but a paired t-test revealed a small (0.03 mmol x L(-1), P < 0.05) significant difference. The coefficient of variation from the three investigators across the 20 samples ranged from 1.3 to 3%. Blood lactate concentration in resting blood samples did significantly increase in value (0.2 mmol x L(-1), P < 0.05) after 7-h exposure to the air, whereas there was no change in maximal exercise blood lactate values after 20-h exposure to the air.
  
  
  CONCLUSIONS
  In a practical context, the Biosen 5030 lactate analyzer was comparable to the other analyzers giving fast reliable measures of blood lactate concentrations over the full range of values, which remained stable over extended periods at room temperature.
authors.affiliation: Department of Sport Science, Canterbury Christ Church University College, United Kingdom. R.C.Davison@cant.ac.uk
authors.forename: R C
authors.initials: RC
authors.lastname: Davison
authors.forename: D
authors.initials: D
authors.lastname: Coleman
authors.forename: J
authors.initials: J
authors.lastname: Balmer
authors.forename: M
authors.initials: M
authors.lastname: Nunn
authors.forename: S
authors.initials: S
authors.lastname: Theakston
authors.forename: M
authors.initials: M
authors.lastname: Burrows
authors.forename: S
authors.initials: S
authors.lastname: Bird
mesh_terms: D015982:Bias; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D015588:Observer Variation; D005082:Physical Exertion / Q000502:physiology; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology; D013048:Specimen Handling; D013696:Temperature; D013997:Time Factors
chemical_list: D019344:Lactic Acid