Diffusion capacity abnormalities for carbon monoxide in patients with COVID-19 at 3-month follow-up
Wei Qin, Shi Chen, Yunxia Zhang, Fen Dong, Zhu Zhang, Bingzhu Hu, Ziyang Zhu, Fajiu Li, Xiaojiang Wang, Yimin Wang, Kaiyuan Zhen, Jing Wang, YuLei Wan, Hongbo Li, Ismaı̈l Elalamy, Chenghong Li, Zhenguo Zhai, Chen Wang
Abstract
Objective To evaluate pulmonary function and clinical symptoms in coronavirus disease 2019 (COVID-19) survivors within 3 months after hospital discharge, and to identify risk factors associated with impaired lung function. Methods and material COVID-19 patients were prospectively followed-up with pulmonary function tests and clinical characteristics for 3 months following discharge from a hospital in Wuhan, China between January and February 2020. Results 647 patients were included. 87 (13%) patients presented with weakness, 63 (10%) with palpitations and 56 (9%) with dyspnoea. The prevalence of each of the three symptoms were markedly higher in severe patients than nonsevere patients (19% versus 10% for weakness, p=0.003; 14% versus 7% for palpitations, p=0.007; 12% versus 7% for dyspnoea, p=0.014). Results of multivariable regression showed increased odds of ongoing symptoms among severe patients (OR 1.7, 95% CI 1.1–2.6; p=0.026) or patients with longer hospital stays (OR 1.03, 95% CI 1.00–1.05; p=0.041). Pulmonary function test results were available for 81 patients, including 41 nonsevere and 40 severe patients. In this subgroup, 44 (54%) patients manifested abnormal diffusing capacity of the lung for carbon monoxide ( D LCO ) (68% severe versus 42% nonsevere patients, p=0.019). Chest computed tomography (CT) total severity score >10.5 (OR 10.4, 95% CI 2.5–44.1; p=0.001) on admission and acute respiratory distress syndrome (ARDS) (OR 4.6, 95% CI 1.4–15.5; p=0.014) were significantly associated with impaired D LCO . Pulmonary interstitial damage may be associated with abnormal D LCO . Conclusion Pulmonary function, particularly D LCO , declined in COVID-19 survivors. This decrease was associated with total severity score of chest CT >10.5 and ARDS occurrence. Pulmonary interstitial damage might contribute to the imparied D LCO .