Patients with Chronic Paralytic/Restrictive Ventilatory Dysfunction: Discussion (2)
All of the patients in this study had dSa02 due to chronic underventilation, periods of upper airway obstruction, or both during BV use. In our population, chronic underventilation would be most likely to occur with use of the less efficient BVs (;ie, the chest shell and the rocking bed). This was supported by the cases of five patients with decreased mean Sa02 and relatively fewer episodes of obstructive dSaOz per hour.
These five patients did not do as well in general as those with more obstructive dSa02 when switched to NV-PAP As suggested previously, the reflex muscle activity that is necessary during sleep to maintain adequate ventilation while on most forms of NV-PAP may be inhibited by the ventilatory drive depression that occurs when chronic hypercapnia is allowed to progress. Four of these five patients had been on continuous oxygen therapy with exacerbated C02 retention and symptoms of hypoventilation before being introduced to BV use. proventil inhaler
We observed in at least seven patients that respiratory control centers could be reset to normal and patients’ symptoms could be greatly relieved by providing effective noninvasive ventilatory aid during daytime hours as well as overnight.