Upper airway function during maximal exercise in horses with obstructive upper airway lesions. Effect of surgical treatment.

The research paper investigates changes in upper airway pressure in racehorses with upper airway obstructions during maximum exercise and how surgical interventions affect pressure levels.

Study Method and Subjects

• The research was conducted on 10 Thoroughbred racehorses. Each of these animals was naturally affected by some form of upper airway obstruction.
• During the study, the horses were subjected to maximum exercise, and their upper airway pressure was measured.

Findings Based on Types of Obstruction

• The researchers found that upper airway obstruction due to left laryngeal hemiplegia and arytenoid chondropathy resulted in substantial increases in inspiratory upper airway pressure (30-40 cm H2O).
• On the other hand, complicated aryepiglottic entrapment and subepiglottic cysts only caused modest increases in pressure (15 cm H2O).
• The least significant increase in upper airway pressure (3-5 cm H2O) was caused by uncomplicated aryepiglottic entrapment and grade IV pharyngeal lymphoid hyperplasia.

Surgical Procedures’ Effect on Airway Pressure

• The surgical procedures generally restored airway pressures to normal limits in most types of obstructions.
• However, subtotal arytenoidectomy only managed to improve but not normalize airway pressures in horses with arytenoid chondropathy.
• The pharyngeal lymphoid hyperplasia appeared to have a negligible effect on upper airway function.

Conclusion

• The study concludes that different forms of upper airway obstruction have varying effects on airway pressure during maximum exercise.
• It also shows the potential of surgical interventions in normalizing these pressure changes, with varying levels of success depending on the specific type of obstruction.