What benefits can be expected from mask ventilation in ALS?

Mask ventilation is initiated in ALS when symptoms of respiratory insufficiency develop or measurement parameters indicate that respiratory dysfunction is present. The expectation of mask ventilation depends on which of these two starting points is present. In the case of stressful symptoms of respiratory effort, it is to be expected that the symptoms will be alleviated by adjusting the breathing mask. Night-time mask ventilation relieves the respiratory muscles so that a recovery effect and easier breathing can be felt during the day.

Another effect of mask ventilation occurs in the lying position or during sleep. Breathing while lying down can be difficult (orthopnoea) and wearing the mask can be experienced as an immediate relief. By improving sleep (with improved gas exchange and a reduced concentration of carbon dioxide in the blood), daytime tiredness can be reduced and a “refreshing effect” of night-time sleep can be restored. Further positive effects of mask ventilation can include reduced bronchial mucus formation: Improved ventilation of the airways and unfolding of the lung tissue through positive pressure ventilation can reduce secretion retention in the bronchi again. This effect can also be expected when using a cough assistant. In patients who start mask ventilation due to reduced respiratory parameters (vital capacity below 70 %) and do not show any subjective symptoms, a positive effect of ventilation therapy can still be expected. In this constellation, the effect is to be understood as prophylactic.

Early use of mask ventilation can prevent or reduce the undesirable effects of inadequate ventilation (lack of lung tissue development, accumulation of bronchial secretions; reduction in gas exchange and accumulation of carbon dioxide). Clinical studies on mask ventilation have shown that early and consistent use of mask ventilation is associated with an improved prognosis (length and quality of life).

These positive effects of mask ventilation should also provide “motivation” for patients who do not experience symptoms of respiratory dysfunction to use mask ventilation continuously and sufficiently (ideally more than eight hours per day).