title: Simplified strong ion difference approach to acid-base balance in healthy foals.
abstract: OBJECTIVE
  To determine the strong ion difference (SIDa ) and total nonvolatile weak buffers (ATOT ) in healthy foals during the first year of life and to compare reference biochemistry laboratory with analyzers available during emergency hours.
  
  
  METHODS
  Prospective study performed over 2 years.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  Two hundred thirty-six healthy foals distributed in 6 groups: A (21 days-2 months), B (2-3 months), C (3-6 months), D (6-9 months), E (9-12 months), and 33 neonatal foals (< 21 days old).
  
  
  METHODS
  Blood samples were obtained to determine L-lactate, sodium, potassium, chloride, and total plasma protein concentrations. In neonatal foals, samples were analyzed using 4 different devices. Reference intervals of SIDa and ATOT for each of the analyzers under comparison were established using mean ± 2 standard deviations. Age effect was evaluated using one-way ANOVA analysis. Linear regression in neonatal foals was employed to obtain a new equation to estimate ATOT from total plasma protein concentration.
  
  
  RESULTS
  A significant age effect was observed for ATOT and SIDa . In all foals younger than 6 months, ATOT values were lower than in older foals (P < 0.003). A clinically and statistically significant difference in SIDa was detected only in the neonatal period (P < 0.001). The equation to estimate ATOT from total plasma protein adjusted for neonatal foals is ATOT = 2.5 × total plasma protein concentration.
  
  
  CONCLUSIONS
  Reference intervals of ATOT should be considered different from adults during the first 6 months of life in horses. Regarding SIDa , values should be considered different only during first 21 days of life.
authors.affiliation: Servei de Medicina Interna Equina, Unitat equina FHCV, i Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Judit
authors.initials: J
authors.lastname: Viu
authors.affiliation: Servei de Medicina Interna Equina, Unitat equina FHCV, i Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Lara
authors.initials: L
authors.lastname: Armengou
authors.affiliation: the Laboratory of Biostatistics and Epidemiology, Universitat Autònoma de Barcelona, and Statistics and Methodology Support Unit, IDIBAPS, Hospital Clínic, Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Ríos
authors.affiliation: the Department of Animal Medicine and Surgery, Equine Sport Medicine Center, CEMEDE, School of Veterinary Medicine, University of Córdoba, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Muñoz
authors.affiliation: Servei de Medicina Interna Equina, Unitat equina FHCV, i Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Jose-Cunilleras
mesh_terms: D000136:Acid-Base Equilibrium; D000418:Albumins; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D002712:Chlorides / Q000097:blood; D005260:Female; D006736:Horses / Q000502:physiology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008954:Models, Biological; D011188:Potassium / Q000097:blood; D011446:Prospective Studies; D012016:Reference Values
chemical_list: D000418:Albumins; D002712:Chlorides; D019344:Lactic Acid; D011188:Potassium
keywords: ATOT; PCO2; SID; horse