Effect of passive pneumoperitoneum on oesophageal pressure, cardiovascular parameters and blood gas analysis in horses.

The research explores the impact of passive pneumoperitoneum (inflation of the abdomen with gas during surgery) on breathing, cardiovascular parameters, and blood gas analysis in horses. The study concludes that it does not negatively influence breathing mechanisms or hemodynamic variables under experimental conditions.

Methods

• The study was conducted on eight healthy mature horses that were equipped with carotid artery and thoracic vena cava catheters (a thin tube placed in a vein to allow access to the bloodstream) and an intraluminal manometry system (a method to measure pressure within the gastrointestinal tract).
• Pneumoperitoneum was established by paralumbar puncture using an 8 gauge needle.
• Several measurements were taken before and at intervals of +5, +10, +15 and +30 minutes after the establishment of pneumoperitoneum. These included vital signs, oesophageal pressure, gastric pressure, arterial and central venous blood pressures, and arterial and mixed venous blood gas analyses.

Results

• The study did not yield significant changes in oesophageal pressure, central venous pressure, and the results of arterial and mixed venous blood gas analysis.
• The arterial diastolic and mean pressures and rectal temperature showed a slight increase (P ≤ 0.05).
• However, these changes in arterial pressure may have occurred in response to the passive pneumoperitoneum or could be related to the handling stress of the horses during the experiment.
• The minor variations in rectal temperature were not clinically significant and are likely a result of the stress associated with restraint during the procedure.

Conclusions

• Under the experimental conditions used in this study, the passive pneumoperitoneum did not impact the breathing mechanics or haemodynamic variables adversely in horses.
• The experiment concludes that it is unlikely that mature horses will show signs of respiratory difficulty due to the development of passive pneumoperitoneum during standing laparoscopy (a surgical procedure where a fiber-optic instrument is inserted through the abdominal wall to view the organs in the abdomen or to permit a surgical procedure).