title: Traditional and quantitative assessment of acid-base and shock variables in horses with atypical myopathy.
abstract: BACKGROUND
  Descriptions of acid-base disturbances in atypical myopathy (AM) are limited.
  
  
  OBJECTIVE
  Describe and compare traditional and quantitative acid-base abnormalities and cardiovascular shock status in horses with AM at admission.
  
  
  METHODS
  34 horses with AM, 15 healthy controls.
  
  
  METHODS
  Retrospective case-control study. Records were searched for shock variables (packed cell volume [PCV], blood urea nitrogen [BUN], heart and respiratory rate) and acid-base variables (venous blood gas analysis, electrolytes, total protein, lactate) on admission. Base excess (BE) of free water (BEfw), chloride (BEcl), total protein (BEtp), and unidentified anions (BEua), anion gap (AG), measured strong ion difference (SIDm), and concentration of total nonvolatile weak acids ([Atot]) were calculated. Acid-base classifications, using simplified strong ion model and traditional approach, and shock grades were assigned. A 2-sample Wilcoxon rank-sum test and Bonferroni correction compared variables in AM cases versus control horses. Significance was P < .05/16 for acid-base and P < .05/5 for shock variables.
  
  
  RESULTS
  Tachycardia, tachypnea, and normal to increased PCV and BUN were common in AM cases. Respiratory, metabolic acid-base alterations, or both were mainly caused by respiratory alkalosis, lactic acidosis, and SIDm alkalosis, alone or in combination. Evaluated variables (except pH, potassium concentration, total protein, and related calculations) were significantly different (P < .001) between AM cases and control horses. The strong ion model provided a more accurate assessment than the traditional approach and identified mixed derangements.
  
  
  CONCLUSIONS
  Acid-base derangements should be evaluated in horses with AM and this preferably with the strong ion model.
authors.affiliation: Department of Epidemiology, Unité de recherche en epidémiologie et analyse de risques appliquées aux sciences vétérinaires, FMV University of Liege, Belgium. gaby@equinespecialists.eu
authors.forename: G
authors.initials: G
authors.lastname: van Galen
authors.forename: S
authors.initials: S
authors.lastname: Cerri
authors.forename: S
authors.initials: S
authors.lastname: Porter
authors.forename: C
authors.initials: C
authors.lastname: Saegerman
authors.forename: L
authors.initials: L
authors.lastname: Lefere
authors.forename: K
authors.initials: K
authors.lastname: Roscher
authors.forename: C
authors.initials: C
authors.lastname: Marr
authors.forename: H
authors.initials: H
authors.lastname: Amory
authors.forename: D M
authors.initials: DM
authors.lastname: Votion
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology*; D000818:Animals; D001806:Blood Urea Nitrogen; D016022:Case-Control Studies; D005260:Female; D006339:Heart Rate; D006400:Hematocrit; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D008297:Male; D009135:Muscular Diseases / Q000378:metabolism / Q000662:veterinary*; D012119:Respiration; D012189:Retrospective Studies