Effects of gastric distension on intraabdominal pressures in horses.

The research article is an experimental study on horses that aims to explore how gastric distension impacts intraabdominal pressures. It finds that the intraabdominal pressures significantly rise when more than 5 litres of water is infused into the horse’s stomach.

Research Methodology

• The study was conducted in a university-based equine research facility, where the subjects were ten healthy adult horses – 5 males and 5 females.
• Intraabdominal pressures (IAP) were directly measured from the intraperitoneal space via an intraperitoneal cannula that was zeroed at a height midway between the height of the tuber ishii and point of the shoulder.
• The IAP measurements were taken at six different times: at rest, after the placement of a nasogastric tube, and after instilling each 5 L increment up to a total of 20 L of water.
• Simultaneously, mean arterial pressures (MAP) were obtained using a tail cuff, and abdominal perfusion pressures (APP) were calculated using the measured IAP minus the measured MAP.

Research Findings

• The experiment found that the baseline direct IAP measurements were subatmospheric (-4.5 ± 3.0 cm H2 O).
• Placement of a nasogastric tube did not significantly impact IAPs, with the change being -2.69, 95% confidence interval (CI) of [-3.24, -2.14], and a P-value of = 0.4195, implying the change was statistically not significant.
• IAPs, however, increased significantly after the instillation of 5 L or more of water into the horse’s stomach. Each additional 5L saw increased IAP with P-values of = 0.0015 after 5L, = 0.0001 after 10L, 15L, and 20L, signifying the changes as statistically significant.
• APP was not significantly different, regardless of the volume of fluid infused into the stomach (P = 0.05 for all comparisons), suggesting that the changes in IAP did not translate into changes in APP.

Conclusion

• The study concluded that Intraabdominal pressures increase significantly when more than 5 L of water is introduced into the stomach.
• This has encouraged further exploration and research in the relationship between gastric pressures and the potential development of intraabdominal hypertension in horses.