Influence of air movement, facemask design and exercise on upper airway, transpulmonary, and transdiaphragmatic pressures in thoroughbred horses.

This research article investigates how air movement, exercise, and facemask design affect upper airway, transpulmonary, and transdiaphragmatic pressures in thoroughbred horses. Although no clear-cut significances were detected, certain trends suggested that biased airflow might influence respiratory functions during physical activity, warranting further exploration.

Research Design and Objectives

• The study aimed to discern the impact of facial airflow, different facemask designs, and exercise on gas exchange and pressures in the upper airway, transpulmonary, and transdiaphragmatic areas in horses.
• It captures data from 6 thoroughbred horses subjected to varied protocols involving different facemask designs and exercise conditions.

Methodology

• The research involved an incremental exercise test performed by the horses on an inclined treadmill (at 10%).
• Each test involved a 2-minute walk, followed by two 2-minute sessions of exercise at intensities that led to 40% and 80% of maximal oxygen consumption.
• Each horse underwent the test four times representing four protocols: no facemask (A); with a mask no controlled airflow (B); with an expiratory bias of 6300 L/min (C); with an inspiratory bias of the same magnitude (D).

Findings and Observations

• No statistically significant changes were detected in arterial blood gases, upper airway (Pu), transpulmonary (PTP), or transdiaphragmatic (PTD) pressures across the different protocols.
• However, certain trends indicated possible physiological importance. For example, the least severe hypoxemia and hypercapnia resulted from protocols A and D, and the most severe from protocol B.
• The protocol D also demonstrated the lowest transpulmonary (PTP) and upper airway (Pu) pressures of all those requiring the use of a mask.

Implications and Conclusions

• The study shines a light on the potential impact of biased airflow on the respiratory function of horses during exercise, though it does not clearly establish this due to lack of clear significant results.
• The difference in respiratory functions across different facemasks and paced exercise could have practical implications for horse training and care, especially when using treadmills.
• These preliminary findings underline the need for more comprehensive studies at greater exercise intensities and with added methodologies to provide a clearer understanding of the issue.