Chest
Clinical InvestigationsPhysiologic Evaluation of Pressure Support Ventilation by Nasal Mask in Patients with Stable COPD
Section snippets
Subjects
Studies were carried out on eight male patients (mean age, 64.6±11.6 [SD] years; weight, 64.0±8.5 kg; height, 162±9 cm), all of whom were smokers or exsmokers with chronic hypercapnia. The physiologic characteristics of the studied population are shown in Table 1. Patient 5 also suffered from a fibrothorax. During the study, the patients were in a stable condition, without exacerbations of respiratory symptoms or any relevant acute disease. All of the patients received long-term oxygen therapy,
RESULTS
One subject (No. 8) was unable to tolerate both ventilators. He suffered from a more severe degree of hyperinflation than the other patients (Table 1). This subject was not included for further analysis. The other seven patients tolerated NPSV with both ventilators without discomfort or complications and all tolerated a PIP of 22 cm H2O. The actual pressure delivered measured at the mask ranged from 17 to 20 cm H2O without any differences between the two ventilators.
Changes in ventilatory
DISCUSSION
The results of this study show that NPSV may be of clinical utility in COPD patients with chronic hypercapnia.
Noninvasive ventilatory support for patients with chronic respiratory failure has been widely used in patients with neuromuscular or chest wall disease1, 2, 3, 4, 5, 6 or with COPD.20, 21 Intermittent negative-pressure ventilation (INPV) with body ventilators has given conflicting results in COPD patients, the sustained improvements in ventilatory function observed by some authors being
ACKNOWLEDGMENTS
The authors wish to thank Antonio Braschi, M.D., for useful talks and Miss Jacqueline McKay for kindly reviewing the English of the manuscript.
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