Weekly cuirass ventilation improves blood gases and inspiratory muscle strength in patients with chronic air-flow limitation and hypercarbia.
We studied the effects of an 8-h, once-a-week schedule of cuirass ventilation (CV) in 5 patients with advanced chronic air-flow limitation and chronic hypercarbia (PaCO2, 58.6 +/- 10.1 mm Hg; mean +/- SD). Repeated measurements of arterial blood gases, maximal inspiratory mouth pressure (P1max), 12-min walking distance, and respiratory cycle were performed during a 1-month run-in period. Quality of life and transdiaphragmatic pressure were measured once. All patients completed the planned 4-month study. Four of them were ventilated for longer periods because CV could not be discontinued at the end of the study. PaCO2 showed a significant fall starting during the first month; PaO2 significantly increased from the second month, whereas P1max significantly rose from the third month on. Maximal transdiaphragmatic pressure increased in the 2 patients with abnormal baseline values. The fall in PaCO2 was associated with an increase in tidal volume because of a longer inspiratory time. Significant improvements in quality of life and in the 12-min walking distance were observed. We conclude that weekly CV improves blood gases, inspiratory muscle strength, and clinical conditions of patients with chronic air-flow limitation and chronic hypercarbia, probably because of correction of chronic inspiratory muscle fatigue.
Gutiérrez
M
M
Departamento de Enfermedades Respiratorias, Facultad de Medicina, Pontificia Universidad Católica de Chile.
Beroíza
T
T
Contreras
G
G
Díaz
O
O
Cruz
E
E
Moreno
R
R
Lisboa
C
C
D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D005069:Evaluation Studies as Topic; D006801:Humans; D006935:Hypercapnia / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D008173:Lung Diseases, Obstructive / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D010100:Oxygen / Q000097:blood*; D012121:Respiration, Artificial / Q000379:methods*; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology*; D013997:Time Factors
D002245:Carbon Dioxide; D010100:Oxygen