Intratracheal oxygen administration increases FIO2 and PaO2 compared with intranasal administration in healthy, standing horses.

This research study compares the effectiveness of two different methods of oxygen delivery – intranasal and tracheal – in horses, concluding that tracheal delivery resulted in better oxygenation.

Study Design

The researchers designed a randomized crossover trial involving six healthy adult horses, with the aim of measuring the impact of different oxygen delivery methods on the horses’ inspired fraction of oxygen (FIO2).

• Each horse was blindly assigned to receive oxygen either through a nasal cannula (group N) or a transcutaneous tracheal catheter (group T).
• This design allowed each horse to serve as its own control, ensuring that variables affecting the outcome of the study were consistent between the two treatment groups.

Procedure

After setting up all necessary equipment and controls, the horses underwent the oxygen delivery procedure.

• Baseline measurements of FIO2 and arterial oxygen partial pressure (PaO2) were first taken while the horses were at rest.
• The horses then received oxygen at a rate of up to 25 mL/kg/min for one hour. The oxygen was delivered either intranasally or via tracheal catheter, depending on the group the horses were randomized to.
• Subsequently, FIO2 and PaO2 were measured at several time intervals during and after the oxygen delivery.
• A statistical analysis was conducted to determine the significant difference between the two groups.

Results

The study found significant improvements in both FIO2 and PaO2 levels as a result of oxygen administration, but with differing impact between the two treatment groups.

• Group T (those receiving tracheal catheter oxygen) showed notably higher FIO2 and PaO2 results compared to group N (those receiving intranasal oxygen).
• It was noted that the time needed for FIO2 and PaO2 to reach equilibrium was less than 10 minutes.

Conclusions

Based on the results, the researchers concluded that the intratracheal approach to oxygen delivery resulted in better oxygenation in horses compared to the intranasal method. Therefore, they recommend consideration of the intratracheal method for horses experiencing severe respiratory difficulties. The study also discovered that equilibration between FIO2 and PaO2 is rapid in adult horses, a finding that could have significant implications for oxygen therapy in veterinary medicine.