[Spirometric reversibility to salbutamol in chronic obstructive pulmonary disease (COPD). Differential effects on FEV1 and on lung volumes].
BACKGROUND
In recent years it has been suggested that in COPD, lung volumes can be modified more than expiratory flows, with bronchodilators.


OBJECTIVE
To study the acute effects of salbutamol on FEV1 and lung volumes at rest.


METHODS
Forty stable COPD patients were studied using a single dose of salbutamol (200 microg). Forced expiratory volume in 1 second (FEV1), slow vital capacity (SVC), forced vital capacity (FVC), and inspiratory capacity (IC) were measured at baseline and after salbutamol administration.


RESULTS
After salbutamol, 39/40 patients exhibited a clinically significant increase in volumes (SVC, FVC or IC > or = 10% predicted). A significant increase in FEV1 (> or = 10% predicted) was observed in only 13 patients.


CONCLUSIONS
Our results demonstrate that changes in lung volumes, and consequently in dynamic lung hyperinflation, take place more frequently than changes in maximal expiratory flows during the spirometric test in patients with COPD. Assessment of spirometric reversibility based only on changes in FEV1 underestimates the effect of bronchodilator drugs in these patients.
Manríquez
Jorge
J
Departamento de Enfermedades Respiratorias, Pontificia Universidad Católica de Chile, Santiago.
Díaz
Orlando
O
Borzone
Gisella
G
Lisboa
Carmen
C
D000280:Administration, Inhalation; D000368:Aged; D000369:Aged, 80 and over; D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects*; D006801:Humans; D007320:Inspiratory Capacity / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D013147:Spirometry
D001993:Bronchodilator Agents; D000420:Albuterol
Reversibilidad espirométrica en la enfermedad pulmonar obstructiva crónica. Efecto diferencial del salbutamol sobre el volumen espiratorio forzado del primer segundo y el volumen pulmonar.