Effect of body position on intra-abdominal pressures and abdominal perfusion pressures measured at three sites in horses anesthetized with short-term total intravenous anesthesia.

The research primarily studies how the body position of a horse, during anesthesia, can affect the intra-abdominal pressure (IAP) and abdominal perfusion pressure (APP). The study deduces that body positioning indeed influences IAP and APP, and these factors should be kept in consideration during the application of anesthesia to horses, particularly, for horses with abdominal diseases.

Research Methodology

• The study was conducted on nine healthy adult horses.
• In order to measure the blood pressure, the horses standing yet unsedated, were inserted with an arterial catheter and three intraperitoneal cannulas for measuring IAP. The cannulas were inserted in three different regions – left flank, right flank, and ventral abdomen.
• The baseline values for heart rate, respiratory rate, systolic arterial blood pressure, mean arterial blood pressure (MAP), diastolic arterial blood pressure, and IAP were measured initially.
• The horses were then sedated with Xylazine and their IAPs and blood pressures were again measured.
• Post this, anesthesia was introduced with a combination of ketamine-diazepam, maintained with a ketamine-guaifenesin infusion. The horses were then positioned twice into left lateral recumbency, right lateral recumbency, or dorsal recumbency.
• Measurements were taken of hemodynamic pressures and accessible abdominal pressures for each recumbency position.
• The APP was then calculated using the equation MAP – IAP.

Results

• From the analysis, it was observed that baseline hemodynamic and IAPs were unchanged after Xylazine administration.
• In dorsal recumbency, there was a substantial decrease in the IAP and MAP for ventral abdomen measured horses.
• Regardless of the changes in position, the ventral abdomen APP remained consistent.
• In the instances of lateral recumbencies, it was observed that flank IAP was lower when compared to the measures during dorsal recumbency, whereas APP was higher than measurements recorded at similar sites during dorsal recumbency.

Conclusion

• The positional change in body affected both the IAP and APP in the healthy anesthetized horses.
• As such, when exploring IAP acquisition methods targeted for horses with abdominal diseases, it is important to consider these effects.