Research Article

[Retracted] Effect of Noninvasive Positive Pressure Ventilation on Prognosis and Blood Gas Level in COPD Patients Complicated with Respiratory Failure

Figure 3

Blood gas analyzer results. Comparison of FEV1 (a), FVC (b), and FEV1/FVC (c). Note: and # have the same meaning as in Figure 2.
(a)
(b)
(c)