Feedback-controlled negative pressure ventilation in patients with stable severe hypercapnic chronic obstructive pulmonary disease.
BACKGROUND
In recent studies, the efficacy of intermittent rest of the inspiratory muscles as an option of treating patients with severe chronic obstructive pulmonary disease (COPD) has become questionable.


OBJECTIVE
The aim of our study was to analyze the effects of feedback-controlled intermittent negative pressure ventilation (INPV) on stable, but severely hypercapnic COPD patients.


METHODS
21 clinically stable, hypercapnic patients with severe COPD underwent INPV with chest shells for 3 weeks, 6 h a day. The INPV sessions were optimized by a visual biofeedback system, which enabled control over the decrease in diaphragmatic activity. Respiratory muscle (RM) function parameters, lung function parameters, blood gases and exercise capacity were analyzed.


RESULTS
In the end, 19 patients concluded INPV treatment. They had PaO(2) of 56.5 +/- 11.8 mm Hg, PaCO(2) of 50.2+/-2.7 mm Hg (mean +/- SD) and FEV(1) of 27.8 +/- 4.3% predicted before treatment. There was no statistically significant change in lung function parameters, RM function parameters, physical performance and level of dyspnea after 3 weeks of INPV.


CONCLUSIONS
We conclude that intermittent RM rest induced by INPV can relax inspiratory muscles in most patients with stable severe COPD, but fails to improve RM function and exercise capacity.
Ludwig Boltzmann Institute for Environmental Pneumology, Pulmonary Department, City Hospital Lainz, Vienna, Austria.
W
W
Kössler
H
H
Lahrmann
H
H
Brath
T
T
Wei
W
W
Frank
M
M
Wild
H
H
Zwick
T
T
Wanke
D000368:Aged; D001676:Biofeedback, Psychology; D004576:Electromyography; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology* / Q000628:therapy*; D008168:Lung / Q000503:physiopathology; D008173:Lung Diseases, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance; D012132:Respiratory Muscles / Q000503:physiopathology; D015919:Ventilators, Negative-Pressure