Use of prototype bi-nasal prongs for noninvasive ventilation in foals

Noninvasive ventilation (NIV) provides effective respiratory support in foals, but face masks are poorly tolerated and associated with hypercapnia. Bi-nasal prongs might be a more effective device interface in foals.

To compare bi-nasal prongs and masks for NIV in foals with pharmacologically induced respiratory insufficiency.

Six healthy foals.

In a randomized cross-over study, sedated foals received NIV delivered by mask or bi-nasal prongs, with the treatment repeated using the alternative device interface after a 3-day rest period. After periods of spontaneous ventilation through the allocated interface, with and without supplementary O₂ (T2-T3), foals were subject to 10-minute treatment periods of NIV at different pressure support (5 or 10 cmH₂O) and end-expiratory pressure settings (5 or 10 cmH₂O), with and without supplementary O₂ (T4-T7). Vital signs, arterial blood gases, spirometry, and gas exchange data were measured in the final 2 minutes of each treatment window.

Bi-nasal prongs were well tolerated and required less manual positioning or monitoring compared to the mask. Partial pressure of carbon dioxide did not increase during NIV with bi-nasal prongs and was lower than observed with masks (mean difference, 8.2 mmHg [95% confidence interval, 4.1-12.2 mmHg] at T6). Oxygenation and respiratory mechanics were improved in all foals and not different between device interfaces.

Nasal prongs were well tolerated, had similar effects on respiratory function, and appeared to ameliorate hypercapnia observed previously during NIV in foals.