Heparinised blood ionised calcium concentrations in horses with colic or diarrhoea compared to normal subjects.

This research focused on comparing ionised calcium concentrations in the blood of horses with colic or diarrhea against healthy horses, in order to assess the stability of certain parameters in stored equine blood and their application in disease states.

Objective and Methodology

• The study aimed to establish ionised calcium and C-terminal PTH (Parathyroid hormone) concentrations in blood from healthy horses. The researchers utilized blood from 20 healthy Warmblood horses.
• The research also assessed the stability of ionised calcium and acid-base values in stored equine heparinised blood and serum. They stored samples at room temperature and subjected some samples to freezing and thawing cycles to observe changes in calcium concentrations.
• The researchers verified the applicability of certain formulas in determining disease states by comparing their predictions against actual findings.

Findings

• The concentration of ionised calcium in the blood of healthy Warmbloods ranged between 1.45-1.75 mmol/l (Michigan State University) and 1.43-1.69 mmol/l (Utrecht University).
• No significant change was observed in the mean serum or heparinised blood ionised calcium concentrations after 102 hours of storage at room temperature. Further, freezing and thawing cycles did not significantly affect the serum ionised calcium concentration.
• The researchers derived a linear regression equation for the prediction of adjusted ionised calcium concentration at pH 7.4, using the ionised calcium concentration and pH in heparinised blood of 20 healthy Warmbloods.
• Upon application of this equation, they noted that the mean adjusted ionised calcium concentration in heparinised blood calculated was 100% of the actual value given by the analyser in healthy horses. In contrast, this formula underestimated the ionised calcium concentration in horses suffering from colic or diarrhea by 0.2 and 0.3% respectively.

Implication

• This study offers valuable input for researchers seeking to understand calcium physiology in healthy and diseased horses. It demonstrates the significance of ionised calcium and C-terminal PTH in equine health.
• The research provides insights into handling and analyzing equine blood samples, such as storage conditions and impacts of freezing and thawing cycles.
• The derived formulas for predicting ionised calcium concentration in diseased horses can serve as a reliable tool in diagnosing and managing illnesses like colic and diarrhea.