Colonic luminal pressure in horses with strangulating and nonstrangulating obstruction of the large colon.

The research investigated the pressure inside the colon in horses with severe or mild obstruction of the large colon, finding that higher internal pressure typically corresponded to more severe conditions and a lower survival rate. These findings suggest that colonic luminal pressure could be used to predict survival outcomes in horses with large colon obstructions.

Study Setup

• The study included a total of 106 horses that were suffering from either strangulating obstruction (SO) or non-strangulating obstruction (NSO) of the large colon.
• The degree of obstruction was considered severe (SO) if there was 270 degrees or more of large colon volvulus (twisting of the large intestine).
• Minor obstructions (NSO) were defined as having less than or equal to 180 degrees of volvulus or a non-strangulating displacement.
• The colonic luminal pressure was measured for each of the horses during a surgical procedure known as a ventral midline celiotomy.

Findings

• It was observed that horses with severe obstructions had notably higher colonic luminal pressures compared to horses with minor obstructions.
• A survival analysis ran across the 59 horses with SO that either survived to hospital discharge or met the metrics specified for categorisation as nonsurvivors.
  • It was found that nonsurviving horses exhibited significantly higher colonic luminal pressures compared to the surviving ones.
• Through the response operating characteristic curves, a luminal pressure of 38 cm H2O was determined as the optimal pressure to separate the SO horses into survivor and nonsurvivor groups.
  • The sensitivity, specificity, and positive and negative predictive values for a colonic luminal pressure greater than 38 cm H2O in predicting nonsurvival were reported as 0.89, 0.91, 0.72 and 0.97, respectively.

Conclusion

• The findings suggest that measuring the colonic luminal pressure can be useful in forecasting survival in horses with large colon volvulus. Higher degrees of colonic luminal pressure were largely indicative of more intense obstructions and were strongly linked to non-survival.