non-invasive ventilation

Due to the partially breathing via the oral route, during non-invasive ventilation and respiratory therapy using face masks or similar devices the normal nasal, pharyngeal and laryngeal spaces are only partially accessible for humidification and heating of the inspired air. Since most devices for gas conditioning available today use contin-uous and/or excessively high gas flow (i.e. CPAP), in case of dry and cold inspiratory gas there is an increased risk to exsiccate and undercool the upper airway which may result in mucosal irritation and inflammation. This has a negative impact on patient compliance, leading to a major reduction in treatment efficiency. Thus also in those applications respiratory gas conditioning is of major importance ([1], [2]).

[1] Sanner BM et al. Effects of CPAP-therapy on infectious complications in patients with obstructive sleep apnea syndrome. Respiration 2001; 68 (5): 483-7

[2] Wiest GH et al. In vivo efficacy of heated and non-heated humidifiers during nCPAP-therapy for obstructive sleep apnoea. Respir Med 2000;94(4): 364-8