Coronavirus disease 2019 (COVID-19) has spread worldwide, having a dramatic impact on healthcare systems. The aim of this study is to evaluate mid-term clinical impact of COVID-19 on respiratory function.

379 patients were evaluated 4 months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis. Patients were divided in two groups based on the presence of pneumonia during COVID-19. Clinical conditions, quality of life, symptomatology, 6-min walk test, pulmonary function test with spirometry and diffusing capacity of the lung for carbon monoxide were analysed. Data were compared to clinical evolution during COVID-19 (development of acute respiratory distress syndrome, need of invasive mechanical ventilation, partial oxygen saturation (S_pO2)/inspiratory oxygen fraction (F_IO2) ratio and pneumonia severity index (PSI)).

After a median 135 days, 260 (68.6%) out of 379 patients referred at least one symptom. Patients who developed pneumonia during COVID-19 showed lower S_pO2 at rest (p<0.001), S_pO2 during 6-min walk test (p<0.001), total lung capacity (p<0.001), airway occlusion pressure after 0.1 s (P_0.1) (p=0.02), P_0.1/maximal inspiratory pressure ratio (p=0.005) and higher Borg category-ratio scale (p=0.006) and modified Medical Research Council breathlessness scale (p=0.003), compared to patients without pneumonia. S_pO2/F_IO2 ratio and PSI during SARS-CoV-2 pneumonia were directly associated with mid-term alteration of S_pO2 at rest (p<0.001) and during 6-min walk test (p<0.001), residual volume (p<0.001), total lung capacity (p<0.001 and p=0.003, respectively) and forced vital capacity (p=0.004 and p=0.03, respectively).

Lung damage during COVID-19 correlates to the reduction of pulmonary function 4 months after acute infection.

2019 年冠状病毒病 (COVID-19) 已在全球蔓延，对医疗保健系统产生了巨大影响。本研究的目的是评估 COVID-19 对呼吸功能的中期临床影响。

379 名患者在严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）诊断 4 个月后接受了评估。根据 COVID-19 期间是否存在肺炎，将患者分为两组。分析临床情况、生活质量、症状学、6分钟步行试验、肺功能检查（肺活量计）和肺对一氧化碳的弥散能力。将数据与 COVID-19 期间的临床演变（急性呼吸窘迫综合征的发展、需要有创机械通气、部分氧饱和度 ( S _{pO 2} )/吸入氧分数 ( F _{IO 2} ) 比率和肺炎严重指数 (PSI)）进行比较.

中位 135 天后，379 名患者中有 260 名 (68.6%) 提到了至少一种症状。在 COVID-19 期间发生肺炎的患者在休息时表现出较低的S _{pO 2} (p<0.001)、在 6 分钟步行试验期间的S _{pO 2} (p<0.001)、总肺活量 (p<0.001)、0.1 后的气道阻塞压力s ( P _0.1 ) (p=0.02)、P _0.1 /最大吸气压力比 (p=0.005) 和更高的 Borg 类别比量表 (p=0.006) 和修改后的医学研究委员会呼吸困难量表 (p=0.003)，与没有肺炎的患者。S _{pO 2} / F _{IO 2}SARS-CoV-2 肺炎期间的比率和 PSI 与休息时 (p<0.001) 和 6 分钟步行试验期间 (p<0.001)、残余体积 (p<0.001)的S _{pO 2}的中期改变直接相关，总肺活量（分别为 p<0.001 和 p=0.003）和用力肺活量（分别为 p=0.004 和 p=0.03）。

COVID-19 期间的肺损伤与急性感染 4 个月后肺功能的降低有关。