The effects of equivalent doses of tromethamine or sodium bicarbonate in healthy horses.

The study is about exploring the effects of tromethamine, a potential treatment for metabolic acidosis in horses, and comparing its outcomes with those of sodium bicarbonate. The study found that both treatments have similar abilities to increase alkalinity, but tromethamine can result in a significant decrease in plasma sodium concentration- a condition known as hyponatremia.

Study Objectives and Design

• The research was designed to examine the impacts of tromethamine and to compare its biochemical outcomes with sodium bicarbonate.
• The study was carried out as a randomized intervention with recurring measures, involving 16 healthy horses ranging from 3 to 17 years old.
• Of the horses, ten were given tromethamine, while six received sodium bicarbonate, each at doses of 3 mEq/kg.
• Data collection involved drawing samples of venous blood and cerebrospinal fluid (CSF) at different times before and after the drug administration, while also recording the horses’ heart and breathing rates at intervals.

Results

• The median base excess increased notably directly after both bicarbonate and tromethamine were administered. This increase was not significantly different between the two treatments.
• The base excess levels trended towards the baseline but remained significantly increased three hours after infusion of either of the treatments.
• Following the tromethamine administration, a significant decrease was observed in the plasma sodium concentration, lasting for about 90 minutes. No such effect was noted after sodium bicarbonate administration.
• Both sodium bicarbonate and tromethamine were found to have increased carbon dioxide tension in the venous blood and CSF.
• Despite the venous alkalemia, a condition where the blood pH becomes more alkaline, the pH of the CSF decreased after both treatments.

Conclusions

• The study found that both tromethamine and sodium bicarbonate have similar alkalinizing abilities. However, the administration of tromethamine causes hyponatremia, a condition characterized by low sodium concentration in the blood.
• Both these substances also increased the carbon dioxide tension in the venous blood and CSF.
• According to the authors, if conditions like hyponatremia, hypercarbia (excessive carbon dioxide in the bloodstream), and acidosis of the CSF occur after giving tromethamine to horses with existing metabolic acidosis, some of the theoretical benefits of tromethamine may not be practically applicable.