1Begin P,Grassino A.Inspiratory muscle dysfunction and c hronic hypercapnia in chronic obstructive pulmonary disease.Am Rev Respir Dis,1991,143:905-912.
2Vitacca M,Porta R,Bianchi L,et al.Differences in spntaneous breathing pattern and mechanics in patients with severe COPD recoving from acute excerbation.Eur Respir J,1999,13:365-370.
3Scano G,Spinelli A,Duranti R,et al.Carbon dioxide responsiveness in COPD patie nts with and without chronic hypercapnia.Eur Respir J,1995,8:75-85.
