Long-term nocturnal mechanical ventilation in patients with restrictive respiratory failure will prevent the nocturnal worsening of their gas exchange and improve their daytime ABG values. Intermittent positive pressure breathing through a closely fitting nasal mask is an effective way to assist ventilation among this population. Despite the mask and associated straps, the quantity and distribution of sleep in our experience is no worse than that measured on the initial night prior to ventilation. Cheap Diskus Advair
The mechanism by which this clinical improvement occurs remains unclear. Rochester et alu measured a significant reduction in diaphragmatic and accessory muscle EMG activity when patients were ventilated with a negative pressure device. Given that most patients have either a marked increase in their work of breathing, weakness of the respiratory muscles, or a combination of both,– they reasoned that the beneficial effects of ventilation are mediated, in part, by a reduction in inspiratory muscle work, thus improving the daytime function of the inspiratory muscles and contributing to the observed clinical improvement. Carrey et al investigated the effects of positive pressure ventilation on inspiratory muscle activity in three normal subjects, four patients with restrictive ventilatory failure, and five patients with obstructive ventilatory failure.