Abnormalities in oxygenation, coagulation, and fibrinolysis in colonic blood of horses with experimentally induced strangulation obstruction.

The research study experimented on horses to identify key variables for the quick indirect measurement of colonic mucosal damage by assessing the divergence in arterial and venous blood gas, coagulation, and fibrinolysis variables in the ischemic and regular large colons.

Objective and Methodology

• The focal point of the study was to identify variables that can be used for fast, indirect measurement of colonic mucosal damage.
• The researchers observed seven clinically healthy horses between ages 2 and 15 for the experiment.
• The experiment involved a surgical procedure where occlusion of the lumen (interior space) and vasculature (arrangement of blood vessels) of the middle part of the large colon in horses was achieved.
• During the experiment, horses underwent ischemia (restriction in blood supply) in a randomly chosen colonic segment for 3 hours followed by reperfusion for 1 hour. Variables were measured at specific intervals throughout this 4-hour period to ascertain colonic mucosal damage.
• The findings from the ischemic colons were compared with histologic scores (determined through a microscopic study of tissue structure) of colonic biopsy specimens to quantify the extent of damage.

Results of the Study

• Significant differences in venous pH, oxygen saturation, oxygen content, arteriovenous oxygen difference, and lactate and glucose concentrations over time were observed when compared to control values.
• The average histological scores of biopsy samples from the ischemic colons were greater, indicating more damage than the control colons. The degree of damage also significantly increased with the duration of ischemia.
• Moreover, the study concluded that among the variables, venous lactate (a product of anaerobic metabolism), oxygen saturation, and PO2 (partial pressure of oxygen) values were the most significant predictors of the severity of histologic damage within ischemic colons.

Conclusions

• The research concluded that venous blood gas measurements, lactate values in the large colon, can serve as effective predictors of intestinal damage endured during 3 hours of ischemia.
• These variables could potentially prove clinically useful for rapid determination of colonic viability, especially in veterinary surgeries where assessing colonic health may be crucial.