Humidification for home non-invasive ventilation

INTERVENTION: Patients prescribed to receive noninvasive ventilation in the home will receive humidification delivered at 31 degrees and 32 mg H2O/L. They will receive this humidification therapy for 6 months, then swap over to the other therapy for 6 months. CONDITION: Stable hypercapnic patients affected by either COPD, neuromuscular disorders or restrictive thoracic disease PRIMARY OUTCOME: Compliance to nocturnal noninvasive ventilation assessed subjectively by a tolerance score and objectively by hours of noninvasive ventilation actually delivered to the patient. SECONDARY OUTCOME: Incidence of colonization of the circuitry. Rate of improvement of ABG. Rate of upper and lower airway infections. Side‐effects associated with chronic use of noninvasive ventilation. INCLUSION CRITERIA: Need for long term noninvasive mechanical ventilation.Informed consent. pH > 7.35 and PaCO2 > 50 mmHg (while breathing room air).