Physiological and functional anatomical principles of humidified high flow therapy (HHFT)

Abstract

When delivering inspiratory gas flows in excess of the physiologic demands while maintaining a positive inspiratory pressure with a humidified high flow herapy via nasal canulas, washout of nasopharyngeal dead space and lower resistances occur. In addition, a positive expiratory pressure inside the pharyngeal vault favours oxygenation, thereby improving respiratory and upper respiratory airway mechanicsThis constant positive pressure inside the pharynx at both inspiratory and expiratory phases decreases energy expenditure through the precise control of warming and humidification of gases.