Gas exchange after Covid-19 pneumonia

ABSTRACT

Introduction: Functional follow-up of patients after Covid-19 pneumonia is essential, not only to adapt patient care but also to better understand the medium and long-term consequences of the virus on respiratory function. Among the respiratory function tests, DLCO allows to evaluate the sequelae on the quality of gas exchanges. Methods: The DLCO was measured as part of a respiratory function assessment, 3 months after recovery from Covid-19 pneumonia in a group of 469 patients. Result(s) Study population was composed of 262 males and 207 females. Mean age and body mass index (BMI) were respectively 59.45+/-12.85 years-old and 31.24+/-5.83 kg/m2. Smoking was reported in 32.9% of cases. Hospitalization was needed on 92.3%, oxygen supply in 91.8% and respiratory aid in 11.1% of cases. Mean DLCO was 74.24%+/-17.7 and was abnormal in 43% of cases whereas restriction and obstruction were found respectively in 14.8% and 4.9% of spirometry. DLCO was correlated with age (r=0.236;p<10-3), BMI (r=-0.097;p=0.036), dyspnea severity according to the mMRC score (r=-0.318;p<10-3), duration of hospitalization (r=-0.13;p=0.008), respiratory aid (r=-0.159;p=0.01), duration of oxygen need (-0.364;p<10-3), extension of pneumonia on the CT scan (r=-0.245;p<10-3), FVC (r=0.521;p<10-3), FEV1 (r=0.479;p<10-3) and TLC (r=0.290;p<10-3). Conclusions: DLCO seems to be one of the first functional parameters to be altered after Covid-19 pneumonia, which justifies its regular measurement in patient follow-up.