Effect of Lung-clearing and Phlegm-removing Herbal Medicine Combined with Positive-pressure Noninvasive Ventilation on Respiratory Failure Patients with Chronic Obstructive Pulmonary Diseases

• 清肺化痰中药配合呼吸机无创正压通气救治慢性阻塞性肺病伴呼吸衰竭的疗效观察