Fluorometric evaluation of large and small intestinal ischaemia in the horse.

The research conducted experimentally induced two types of obstructions within the small and large intestines of anaesthetised horses, then investigated differences in fluorescence after administering sodium fluorescein. Fluorescence was measured as a method to evaluate the severity and extent of intestinal ischemia – a condition where blood supply to the intestines is constrained or blocked.

Study Methodology and Procedure

• The research involved eight anaesthetised horses, within whose small intestines two types of obstructions were artificially induced – Arteriovenous (ischaemic strangulating obstruction, ISO) and venous obstructions (haemorrhagic strangulating obstruction, HSO), with each obstruction lasting 70 minutes.
• In the large colon of half the horses, ISO was induced for 2 hours, and in the other half for 3 hours, at the sternal and diaphragmatic flexures of the large colon.
• Following the release of these obstructions after the specific durations, 20% sodium fluorescein was administered intravenously (0.5 mg/kg bodyweight).
• Fluorescence of each of the intestines, including the injured segments and one control segment, was quantitatively measured at intervals of 2, 10, 15, 20 and 30 minutes with the use of a fibreoptic perfusion fluorometer.

Study Findings

The findings of the study were as follows:

• In the small intestine, significant fluorescence differences were observed between HSO and control segments and between ISO and HSO. However, there was no significant difference in fluorescence between ISO and control segments.
• In the large colon, there were significant differences in fluorescence between the ischaemic 3-hour ventral colon and control segments, as well as a trend in differences between the 2 and 3-hour ischaemic segments.
• No significant differences in fluorescence were seen between the 2 versus 3-hour dorsal colon segments, nor between 2 or 3-hour dorsal colon and control segments.

Concluding Remarks

The study provides insights into the effects and severity of intestinal ischemia in horses through the use of fluorescence measurements. This can potentially allow for better assessment and understanding of the condition, which is crucial for appropriate intervention and treatment. However, more research may be required to link these differences in fluorescence with clinical outcomes in the horses, and to further validate the methodology.