Efficacy of Positive vs Negative Pressure Ventilation in Unloading the Respiratory Muscles: Discussion (5)

The fact that PPV is able to substantially reduce diaphragmatic work in both awake and sleeping subjects suggests that this may be the preferred method of AV to be used in future studies. Other questions that must be examined include the effect of PPV during both non-REM and REM sleep, and patient acceptance of and comfort with the nasal mask. Previous experience in patients with suggests that long-term nasal nocturnal PPV is well tolerated. In these studies, PPV was delivered nightly for three to five months. In one study, PPV was delivered to patients with both COPD and restrictive disease for three to nine months. Improvements in control of oxygenation and quality of sleep were superior in the restricted vs the obstructed patients. However, both groups demonstrated an improvement in arterial gas tensions and good acceptance of the nasal masks.
Since submission of this article, a study by Carrey Z, Gotfried SB, and Levy RD, “Ventilatory Muscle Support in Respiratory Failure with Nasal Positive Pressure Ventilation,” (Chest 1990; 97:150-58) has appeared. The results showed that positive pressure ventilation applied through a nasal mask reduced inspiratory muscle activity in normals and patients with restrictive and obstructive pulmonary disease.

Category: Lung function

Tags: neuromuscular, neuromuscular disease, patients copd, ventilatory muscle