1Plant PK, Owen JL, Elliott MW. Early use of non- invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease on general respiratory wards:a multicentre randomized controlled trial. Lancet, 2000,335:1931~ 1935
2Mehta S,Hill NS. Noninvasive ventilation. AM J Respir Crit Vare Med, 2001,163: 540~ 577
3Bronchard L. Non-invasive ventitalion for acute exacerbation of COPD a new standard of care. Thorax,2000,55 :817~818