Physical Medicine Interventions for Duchenne Muscular Dystrophy, the Including Avoiding Invasive Airway Tubes

17 If symptoms are not entirely eliminated and sleep O2 sat baseline night normal, excessive insufflation air leakage using nasal NVS can be avoided by switching to lip cover interfaces like the Oracle TM or using oronasal systems that provide essentially closed NVS support. Such interfaces deliver air via the mouth and nose during sleep. NVS ventilator settings range from 650 to 1500 ml with the patient choosing. Most eventually set the ventilator for 1100 to 1300 ml. Patients vary the volumes of air taken in from cycle to ventilator cycle and from breath to breath to vary the volume of speech and to maximize cough flows as well as to air stack to expand the lungs. Pressure assist control of about 20 cm H2O is used if there is too much air swallowing during sleep. No PEEP/EPAP or supplemental O2. B. Intermittent Abdominal Pressure Ventilator (IAPV) Another daytime noninvasive interface is the IAVP. This involves the intermittent inflation of an elastic air sac that is contained in a corset or belt worn beneath the patient’s outer clothing (Figure 8) (Dano Carbone, Porta-Lung Inc., Colorado; Dima Italia LLC, Italy). The sac is cyclically inflated by a positive pressure ventilator. Inflation of the air chamber moves the diaphragm upwards to assist breathing as the diaphragm returns back down due to gravity. Thus, a trunk angle of 30° or more from the horizontal is necessary. If the patient has any inspiratory capacity, or is capable of frog breathing, he or she can add volumes of air to that taken mechanically. The IAVP generally augments breath volumes by about 300 ml, but volumes as high as 1200 ml have been reported. 24 Patients with less than 1 hour of breathing tolerance, especially when socially active, usually prefer the IAVP to mouthpiece or nasal NVS since it can be all but impossible to know they use a ventilator. Figure 7 - NVS via nasal pillows interface.