title: Validation of the handheld Lactate-Pro analyzer for measurement of blood L-lactate concentration in cattle.
abstract: BACKGROUND
  Blood L-lactate concentration (LAC) can be used for various diagnostic purposes in cattle. As multiple handheld analyzers for LAC exist, it is important to validate their use in cattle in comparison with reference laboratory blood analyzers.
  
  
  OBJECTIVE
  The objectives of this study were to validate the handheld Lactate Pro meter (LacP) including reproducibility, and compare the measurements with the StatProfile (StatP) as a gold standard. In addition, diagnostic sensitivity and specificity, and the impact of HCT on LAC measured by both analyzers were assessed.
  
  
  METHODS
  A cohort of 64 cattle with acute medical and surgical conditions was studied. Whole blood samples in heparin lithium tubes were analyzed upon arrival with both StatP and LacP. Twenty-three samples were immediately retested to assess intra-assay coefficient of variation (CV). The HCT values were also recorded.
  
  
  RESULTS
  The LAC using LacP was highly correlated with the StatP (r = 0.9736 [95% confidence interval [CI]: 0.9562-0.9841]). The LacP underestimated LAC (mean difference:-0.9 mmol/L, 95% CI:-3.1 mmol/L to 1.3 mmol/L). The intra-assay CV was excellent (4.77%). No significant correlation was observed between LacP or StatP and HCT (P = .39 and .09, respectively). Sensitivity and specificity for LacP were 91.7% (95% CI: 76.4-97.8%) and 100% (83.4-100%, cutoff of 4 mmol/L), and 78.6% (58.5-90.9%) and 100% (87.0-100%, cutoff of 6 mmol/L).
  
  
  CONCLUSIONS
  The LacP handheld lactate meter can be used safely and reliably cow-side, although it underestimates LAC value when compared with a standard laboratory analyzer especially for LAC ≥ 10.0 mmol/L. The LAC value was not influenced by HCT in this study.
authors.affiliation: Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montréal, Montréal, QC, Canada.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Buczinski
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Doré
authors.forename: Guillaume
authors.initials: G
authors.lastname: Boulay
authors.forename: David
authors.initials: D
authors.lastname: Francoz
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood*; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis; D005260:Female; D006400:Hematocrit / Q000662:veterinary; D019344:Lactic Acid / Q000097:blood*; D019095:Point-of-Care Systems / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D019344:Lactic Acid
keywords: Biochemistry; bovine; dairy; handheld analyzer; lactatemia