Internal medicine

Organic chemistry

Lung volumes

Fraction of inspired oxygen

Functional residual capacity

Cardiology

Asthma

Chemistry

Mechanical ventilation

Lung

Pneumonia

Spirometry

Oxygen saturation

Respiratory system

Oxygen

Medicine

Pulmonary function testing

European Respiratory Journal

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 (SpO2 )/inspiratory oxygen fraction (FIO2 ) 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 SpO2 at rest (p<0.001), SpO2 during 6-min walk test (p<0.001), total lung capacity (p<0.001), airway occlusion pressure after 0.1 s (P0.1) (p=0.02), P0.1/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. SpO2 /FIO2 ratio and PSI during SARS-CoV-2 pneumonia were directly associated with mid-term alteration of SpO2 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.

Medium-term impact of COVID-19 on pulmonary function, functional capacity and quality of life