Presented in part as a poster at the 2012 ACVIM Forum, New Orleans, Louisiana. This study was performed at the Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
Physicochemical Interpretation of Acid-Base Abnormalities in 54 Adult Horses with Acute Severe Colitis and Diarrhea
Article first published online: 3 APR 2013
Copyright © 2013 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 27, Issue 3, pages 548–553, May/June 2013
How to Cite
Gomez, D.E., Arroyo, L.G., Stämpfli, H.R., Cruz, L.E. and Oliver, O.J. (2013), Physicochemical Interpretation of Acid-Base Abnormalities in 54 Adult Horses with Acute Severe Colitis and Diarrhea. Journal of Veterinary Internal Medicine, 27: 548–553. doi: 10.1111/jvim.12071
- Issue published online: 9 MAY 2013
- Article first published online: 3 APR 2013
- Manuscript Accepted: 7 FEB 2013
- Manuscript Revised: 17 JAN 2013
- Manuscript Received: 19 OCT 2012
- Anion gap;
- Strong ion difference;
- Strong ion gap
The quantitative effect of strong electrolytes, pCO2, and plasma protein concentration in determining plasma pH and bicarbonate concentrations can be demonstrated with the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess the presence or absence of unmeasured anions.
The physicochemical approach is useful for detection and explanation of acid-base disorders in horses with colitis. AG and SIG accurately predict hyperlactatemia in horses with colitis.
Fifty-four horses with acute colitis and diarrhea.
Retrospective study. Physicochemical variables were calculated for each patient. ROC curves were generated to analyze sensitivity and specificity of AG and SIG for predicting hyperlactatemia.
Physicochemical interpretation of acid-base events indicated that strong ion metabolic acidosis was present in 39 (72%) horses. Mixed strong ion acidosis and decreased weak acid (hypoproteinemia) alkalosis was concomitantly present in 17 (30%) patients. The sensitivity and specificity of AG and SIG to predict hyperlactatemia (L-lactate > 5 mEq/L) were 100% (95% CI, 66.4–100; P < .0001) and 84.4% (95% CI, 70.5–93.5 P < .0001). Area under the ROC curve for AG and SIG for predicting hyperlactatemia was 0.95 (95% CI, 0.86–0.99) and 0.93 (95% CI, 0.83–0.99), respectively.
Conclusion and Clinical relevance
These results emphasize the importance of strong ions and proteins in the maintenance of the acid-base equilibria. AG and SIG were considered good predictors of clinically relevant hyperlactatemia.