Physicochemical interpretation of acid-base abnormalities in 54 adult horses with acute severe colitis and diarrhea.

This research study aims to explain the effect of variables such as strong electrolytes, pCO2, and plasma protein concentration on the plasma pH and bicarbonate concentrations in horses with acute colitis using a physicochemical approach. The results showed that strong ion metabolic acidosis was present in many of the horses, and the plasma anion gap (AG) and strong ion gap (SIG) measurements were effective in predicting a high level of lactate in the blood, or hyperlactatemia.

Research Objectives and Methodology

• The main objective of this study was to investigate the value of the physicochemical approach in identifying and explaining acid-base imbalances in horses suffering from acute colitis. This approach uses variables like electrolytes, pCO2, and plasma protein concentration to determine plasma pH and bicarbonate concentration.
• The researchers conducted a retrospective study that involved 54 adult horses diagnosed with acute colitis and diarrhea. They calculated physicochemical variables for each patient and used the measurements of AG and SIG to predict the presence of hyperlactatemia (an excess level of lactate in the blood).
• The sensitivity and specificity of AG and SIG as indicators were analyzed using Receiver Operating Characteristic (ROC) curves. The area under the ROC curve was used to determine the accuracy of these indices in predicting hyperlactatemia.

Study Findings

• The results showed that 72% of the horses had strong ion metabolic acidosis, a condition where the body either produces too much acid or the kidneys are not removing enough acid from the body.
• There was a concurrent presence of mixed strong ion acidosis and decreased weak acid (hypoproteinemia) alkalosis in 30% of the patients. This suggests the acid-base equilibrium in these horses was effected both by heightened ion acidosis and decreased protein levels.
• The sensitivity and specificity of the AG and SIG in predicting hyperlactatemia were found to be 100% and 84.4% respectively, showing a high accuracy in these indicators for confirming the disorder.

Conclusion

• These results highlight the significant role of strong ions and proteins in maintaining the acid-base balance in the body. It suggests that AG and SIG can serve as reliable predictors of clinically relevant hyperlactatemia in horses with acute colitis.
• The findings of this research could help vets better understand, diagnose, and treat acid-base abnormalities in horses with acute severe colitis and diarrhea using the physicochemical approach.