DÃÂaz-Lobato S, Galarza-Jiménez, Barbero-Herranz E and Mayoralas-Alises S
High flow nasal cannula (HFNC) is a new therapeutic approach to patients with several forms of respiratory failure. Studies have shown that HFNC generates a low level of positive airway pressure, improves oxygenation, increases the end-expiratory lung volume, reduces airway resistance, increases functional residual capacity and alveolar recruitment and flushes nasopharyngeal dead space, thus helping to decrease the work of breathing. There is a better control of FiO2 and the gas humidification ensures a better patient tolerance and comfort. Due to a better mucociliary clearance, pulmonary defense mechanisms are restored. The low levels of pressure generated by HFNC may suggest that perhaps could play a role in the treatment of sleep apnea. Some studies have demonstrated a positive effect of HFNC on the apnea-hypopnea index showing us that HFNC could be an alternative to conventional treatment of obstructive sleep apnea in children and adults with fruitful results. We present a review of available evidence.