Effects of early pulmonary rehabilitation exercise on the lung function and indicators of arterial blood gas analysis in patients with severe chronic obstructive pulmonary disease (早期分阶段肺康复锻炼对重症慢性阻塞性肺疾病患者肺功能及血气指标的影响) - XU Nannan (徐楠楠); HONG Hanhan (洪涵涵) (中西医结合护理, 2024)