Effect of furosemide and subsequent intravenous fluid administration on right atrial pressure of splenectomized horses.

The study investigates the influence of intravenous fluid administration on the reduction in right atrial pressure and blood volume caused by furosemide in splenectomized horses.

Research Methodology

• The research involved five horses that had their spleens removed (splenectomized).
• Right atrial pressure (RAP) was measured by a micro-manometer placed in the right atrium.
• Blood was drawn from the jugular vein to measure hematocrit, plasma total protein concentration, and hemoglobin concentration.
• Measurements were taken before the administration of furosemide (a diuretic drug), then every 15 minutes for the next 240 minutes.
• 120 minutes post furosemide administration, polyionic fluids (specifically Lactated Ringer’s solution) were administrated at a regular interval of 15 minutes for the next 120 minutes.

Research Findings

• Furosemide administration resulted in a statistically significant decrease in RAP and blood Volume (BV).
• The administration of polyionic fluids helped restore both the RAP and BV in horses.
• The volume of polyionic fluids administered was found to be similar to the volume of urine produced, indicating that the furosemide-induced reduction in BV was compensated by fluid administration.
• No clear link was found between changes in BV and RAP before or after fluid administration.

Conclusions

• The effect of furosemide on the RAP of horses is primarily mediated by its ability to reduce blood volume.
• Nonetheless, the study concluded that the impact of furosemide on venous compliance (the ability of the vein to expand and contract with changes in pressure) cannot be excluded as a contributing factor to the observed reduction in RAP.