Cardiopulmonary measurements in six horses with naturally-acquired colic (acute abdominal crisis).

The study investigates whether horses with naturally acquired colic exhibit severe cardiopulmonary compromise identical to decrease in cardiac index (CI) and mean arterial blood pressure (MAP). The research involved a sample of six horses requiring surgery due to acute abdominal crises, and their cardiovascular measurements were taken at various stages. The findings revealed that not all horses with naturally acquired colic show evidence of cardiopulmonary compromise.

Methodology

• Six horses presented with acute abdominal crises requiring surgery were selected for the study.
• These horses were equipped for cardiovascular measurements, including the determination of cardiac output by thermodilution.
• Data were gathered or measured at eight distinct time periods, some of which included when the animals were awake, anesthetized, pre-incision, spontaneous ventilation, and post decompression or correction of the lesion.

Results

• The study revealed considerable individual variation, as expected with a clinical study.
• Heart rate, CI, MAP, and PaCO2 were all measured at the different time periods.
• The results revealed significant decreases in MAP and significant increases in PaCO2 during anesthesia and surgery. However, the CI did not exhibit significant changes throughout the study.

Findings

• Before anesthetization, and after treatment with various analgesics, the horses with colic had CI values around 37% lower than clinically normal horses. However, this was only about 12% lower than that observed in sedated clinically normal horses.
• During anesthesia and surgery, horses with colic had CI values around 10% lower than clinically normal anesthetized horses, and similar to CI values reported in two experimental models of colic.
• Some horses with naturally acquired colic showed evidence of cardiopulmonary compromise as indicated by decreased CI and MAP, but this was not universally observed.
• MAP was found not to be a reliable predictor of CI.

Conclusions

• The research provides important insights into the cardiovascular impacts of colic in horses.
• These findings could have implications for how horses with colic are treated and managed in order to mitigate any cardiopulmonary risks.
• Further research on a larger sample size could provide more definitive findings.