[Increase in hypercapnia in exercise--an unloading strategy?].
BACKGROUND
Chronic hypercapnia seems to preserve the overloaded respiratory pump from manifest muscle failure. In order to get information about the regulation of the ventilation under exercise we investigated clinical stable hypercapnic patients.


METHODS
Twenty-one patients (20 males, 53.7 +/- 13.2 years) with obesity-hypoventilation syndrome (8), chronic obstructive lung disease (4), scoliosis (3), myopathy (2) and post-Tbc (2) were examined. Ventilation parameters (fb, Vt, VO2), respiratory muscle strength (PImax, PEmax), arterial blood gases (pO2, pCO2), respiratory quotient (RQ) and lactate were measured at rest and at the end of 5 minutes of maximal bicycle exercise. The control group consisted of 10 healthy persons.


CONCLUSIONS
A significant augmentation of the pre-existing hypercapnia under exercise (reflecting hypoventilation in relation to the predicted value) was observed in all patients with chronically overloaded respiratory muscles. This mechanism seems to be wise because it protects the respiratory pump from failure.
Schönhofer
B
B
Fachkrankenhaus Kloster Grafschaft, Zentrum für Pneumologie und Allergologie, Schmallenberg-Grafschaft.
Geibel
M
M
Wenzel
M
M
Rosenblüh
J
J
Köhler
D
D
D000328:Adult; D002245:Carbon Dioxide / Q000097:blood; D005080:Exercise Test; D005260:Female; D006699:Home Care Services; D006801:Humans; D006935:Hypercapnia / Q000209:etiology / Q000503:physiopathology*; D007385:Intermittent Positive-Pressure Ventilation; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008173:Lung Diseases, Obstructive / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D010100:Oxygen / Q000097:blood; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology*; D015656:Respiratory Mechanics / Q000502:physiology*; D012132:Respiratory Muscles / Q000503:physiopathology
D007773:Lactates; D002245:Carbon Dioxide; D019344:Lactic Acid; D010100:Oxygen