Dynamic changes of pulmonary diffusion capacity in survivors of non-critical COVID-19 during the first six months

Mu Chen; Jingwei Liu; Ping Peng; Wenhua Jian; Yi Gao; Liman Fang; Yanhui Yu; Shuxin Zhong; Hui Peng; Xilong Deng; Yuqi Zhou; Sheng Du; Ruchong Chen; Xiaoneng Mo; Nanshan Zhong; Shiyue Li

doi:10.1016/j.eclinm.2021.101255

Dynamic changes of pulmonary diffusion capacity in survivors of non-critical COVID-19 during the first six months

EClinicalMedicine. 2022 Jan:43:101255. doi: 10.1016/j.eclinm.2021.101255. Epub 2022 Jan 6.

Authors

Mu Chen¹, Jingwei Liu², Ping Peng¹, Wenhua Jian², Yi Gao², Liman Fang^{2

3}, Yanhui Yu⁴, Shuxin Zhong^{2

3}, Hui Peng¹, Xilong Deng¹, Yuqi Zhou⁵, Sheng Du², Ruchong Chen^{2

3}, Xiaoneng Mo¹, Nanshan Zhong^{2

6}, Shiyue Li^{2

6}

Affiliations

¹ Guangzhou Eighth People's Hospital, Guangzhou Medical University, Guangzhou 510060, China.
² State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
³ Department of Allergy and Clinical Immunology, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
⁴ Guangdong Second Provincial General Hospital, Guangzhou 510317, China.
⁵ The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China.
⁶ Guangzhou Laboratory, Bio-Island, Guangzhou 510320, China.

Abstract

Background: The dynamic trends of pulmonary function in coronavirus disease 2019 (COVID-19) survivors since discharge have been rarely described. We aimed to describe the changes of lung function and identify risk factors for impaired diffusion capacity.

Methods: Non-critical COVID-19 patients admitted to the Guangzhou Eighth People's Hospital, China, were enrolled from March to June 2020. Subjects were prospectively followed up with pulmonary function tests at discharge, three and six months after discharge.

Findings: Eighty-six patients completed diffusion capacity tests at three timepoints. The mean diffusion capacity for carbon monoxide (D_LCO)% pred was 79.8% at discharge and significantly improved to 84.9% at Month-3. The transfer coefficient of the lung for carbon monoxide (K_CO)% pred significantly increased from 91.7% at discharge to 95.7% at Month-3. Both of them showed no further improvement at Month-6. The change rates of D_LCO% pred and K_CO% pred were significantly higher in 0-3 months than in 3-6 months. The alveolar ventilation (V_A) improved continuously during the follow-ups. At Month-6, impaired D_LCO% pred was associated with being female (OR 5.2 [1.7-15.8]; p = 0.004) and peak total lesion score (TLS) of chest CT > 8.5 (OR 6.6 [1.7-26.5]; p = 0.007). D_LCO% pred and K_CO% pred were worse in females at discharge. And in patients with impaired diffusion capacity, females' D_LCO% pred recovered slower than males.

Interpretation: The first three months is the critical recovery period for diffusion capacity. The impaired diffusion capacity was more severe and recovered slower in females than in males. Early pulmonary rehabilitation and individualized interventions for recovery are worthy of further investigations.

Keywords: COVID-19; Dynamic changes; Pulmonary diffusion capacity.