Effects of nasal high flow on ventilation in volunteers, COPD and idiopathic pulmonary fibrosis patients.

A high flow of air applied by large bore nasal cannulae has been suggested to improve symptoms of chronic respiratory insufficiency. In pediatric patients, nasal high-flow (nHF) ventilation was similarly effective compared to noninvasive ventilation with a face mask. The aim of this study was to describe changes in respiratory parameters. We measured pressure amplitudes during the respiratory cycle and mean pressures in patients with idiopathic pulmonary fibrosis (IPF) and COPD. In order to achieve tidal volume and minute volume measurements, we used a polysomnography device. Capillary blood was taken for blood gas analysis before and after nHF breathing (8 h). nHF led to an increase in pressure amplitude and mean pressure in healthy volunteers and in patients with COPD and IPF in comparison with spontaneous breathing. In COPD, nHF increased tidal volume, while no difference in tidal volume was observed in patients with IPF. Interestingly, tidal volume decreased in healthy volunteers. Breathing rates and minute volumes were reduced in all groups. Capillary pCO2 decreased in patients with IPF and COPD. nHF resulted in significant effects on respiratory parameters in patients with obstructive and restrictive pulmonary diseases. The rise in pressure amplitude and mean pressure and the decrease in breathing rate and minute volume will support inspiratory efforts, helps to increase effectiveness of ventilation and will contribute to a reduction in the work of breathing. A CO2 wash-out effect in the upper airway part of the anatomical dead space may contribute to the beneficial effects of the nHF instrument.

Bräunlich J ，Beyer D ，Mai D ，Hammerschmidt S ，Seyfarth HJ ，Wirtz H ... -  《-》

Nasal highflow improves ventilation in patients with COPD.

Bräunlich J ，Köhler M ，Wirtz H 《International Journal of Chronic Obstructive Pulmonary Disease》

Nasal high-flow therapy reduces work of breathing compared with oxygen during sleep in COPD and smoking controls: a prospective observational study.

Patients with chronic obstructive pulmonary disease (COPD) endure excessive resistive and elastic loads leading to chronic respiratory failure. Oxygen supplementation corrects hypoxemia but is not expected to reduce mechanical loads. Nasal high-flow (NHF) therapy supports breathing by reducing dead space, but it is unclear how it affects mechanical loads of patients with COPD. The objective of this study was to compare the effects of low-flow oxygen and NHF therapy on ventilation and work of breathing (WOB) in patients with COPD and controls during sleep. Patients with COPD (n = 12) and controls (n = 6) were recruited and submitted to polysomnography to measure sleep parameters and ventilation in response to administration of oxygen and NHF. A subset of six patients also had an esophageal catheter inserted for the purpose of measuring WOB. Patients with COPD had similar minute ventilation (V̇e) but lower tidal volumes than matched controls. With oxygen, [Formula: see text]was increased and V̇e was reduced in both controls and patients with COPD, but there was an increase in transcutaneous CO2 levels. NHF produced a greater reduction in V̇e and was associated with a reduction in CO2 levels. Although NHF halved WOB, oxygen produced only a minor reduction in this parameter. We conclude that oxygen produced little change in WOB, which was associated with CO2 elevations. On the other hand, NHF produced a large reduction in V̇e and WOB with a concomitant decrease in CO2 levels. Our data indicate that NHF improves alveolar ventilation during sleep compared with oxygen and room air in patients with COPD and therefore can decrease their cost of breathing. Nasal high-flow (NHF) therapy can support ventilation in patients with chronic obstructive pulmonary disease during sleep by decreasing the work of breathing and improving CO2 levels. On the other hand, oxygen supplementation corrects hypoxemia, but it produces only a minimal reduction in work of breathing and is associated with increased CO2 levels. Therefore, NHF can be a useful method to assist ventilation in patients with increased respiratory mechanical loads.

Biselli PJ ，Kirkness JP ，Grote L ，Fricke K ，Schwartz AR ，Smith P ，Schneider H ... -  《-》

Nasal high flow reduces minute ventilation during sleep through a decrease of carbon dioxide rebreathing.

Pinkham M ，Burgess R ，Mündel T ，Tatkov S ... -  《-》

[Comparison of volume preset and pressure preset ventilators during daytime nasal ventilation in chronic respiratory failure].

Perrin C ，Wolter P ，Berthier F ，Tamisier R ，Jullien V ，Lemoigne F ，Blaive B ... -  《-》