Patients with Chronic Paralytic/Restrictive Ventilatory Dysfunction (1)
There have been reports on the long-term use of negative-pressure body ventilators (BVs) for assisting the ventilation of patients with paralytic/restrictive ventilatory insufficiency’ and for respiratory muscle rest for patients with chronic obstructive pulmonary disease (COPD). There have, however, been isolated reports of upper airway obstruction associated with apneas and severe episodic oxyhemoglobin desaturation (dSa02) in patients ventilated in this manner, particularly during rapid eye movement (REM) sleep. buy birth control online
The suggested pathophysiology has included collapse of the upper airway during the BV inspiratory maneuver. Guilleminault et al reported failure of chest-shell ventilators to significantly decrease the number of apneas and hypopneas occurring in five severely kyphoscoliotic patients with symptomatic obstructive sleep apnea syndrome (OSAS). Five normal subjects also demonstrated a not statistically significant increase in apneas and hypopneas while using a BV (pneumowrap ventilator) by comparison with unassisted breathing during sleep. In one of these cases, dSa02 to as low as 69 percent occurred during use of the BV. Obese patients and those with pharyngeal muscle weakness due to neuromuscular disease may be at greater risk for obstructive dSa02 during BV use.