A Follow-Up Study of Lung Function and Chest Computed Tomography at 6 Months after Discharge in Patients with Coronavirus Disease 2019

Abstract

We aimed to investigate changes in pulmonary function and computed tomography (CT) findings in patients with coronavirus disease 2019 (COVID-19) during the recovery period. COVID-19 patients underwent symptom assessment, pulmonary function tests, and high-resolution chest CT 6 months after discharge from the hospital. Of the 54 patients enrolled, 31 and 23 were in the moderate and severe group, respectively. The main symptoms 6 months after discharge were fatigue and exertional dyspnea, experienced by 24.1% and 18.5% of patients, respectively, followed by smell and taste dysfunction (9.3%) and cough (5.6%). One patient dropped out of the pulmonary function tests. Of the remaining 54 patients, 41.5% had pulmonary dysfunction. Specifically, 7.5% presented with restrictive ventilatory dysfunction (forced vital capacity <80% of the predicted value), 18.9% presented with small airway dysfunction, and 32.1% presented with pulmonary diffusion impairment (diffusing capacity for carbon monoxide <80% of the predicted value). Of the 54 patients enrolled, six patients dropped out of the chest CT tests. Eleven of the remaining 48 patients presented with abnormal lung CT findings 6 months after discharge. Patients with residual lung lesions were more common in the severe group (52.6%) than in the moderate group (3.4%); a higher proportion of patients had involvement of both lungs (42.1% vs. 3.4%) in the severe group. The residual lung lesions were mainly ground-glass opacities (20.8%) and linear opacities (14.6%). Semiquantitative visual scoring of the CT findings revealed significantly higher scores in the left, right, and both lungs in the severe group than in the moderate group. COVID-19 patients 6 months after discharge mostly presented with fatigue and exertional dyspnea, and their pulmonary dysfunction was mostly characterized by pulmonary diffusion impairment. As revealed by chest CT, the severe group had a higher prevalence of residual lesions than the moderate group, and the residual lesions mostly manifested as ground-glass opacities and linear opacities.

Long-Term Impact of COVID-19: A Systematic Review of the Literature and Meta-Analysis

“…This review identified a total of 24 articles that explore persistent effects of COVID-19 beyond 3 months of follow-up on patients lung imaging, lung function, respiratory symptoms, fatigue, functional capacity, HRQoL, and/or the ability to return to work [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. The studies were completed in China (7), Canada (3), France (2), Norway (2), Italy (3), USA (2), Switzerland (1), Austria (1), Iran (1), the Netherlands (1), and the UK (1).…”

“…Thirteen articles report the results of chest CT scans in post COVID-19 patients at a mean of 3.8 (SD 1.3) months follow-up [ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 36 , 37 , 40 , 41 , 43 , 45 ] ( Supplementary Table S2 and Figure S1 ). Persistent chest CT abnormalities attributable to COVID-19 were identified in 59% of the patients (95% CI 44–73, I 2 = 96%) ( Table 2 ).…”

“…One study reports a higher prevalence of fatigue in patients with severe COVID-19 [29], and another found a lower prevalence of dyspnea (mMRC) in patients with moderate-to-critical illness compared with patients with mild disease [45]. However, disease severity is not significantly associated with the prevalence of fatigue or respiratory symptoms at follow-up in other studies [30,35,41,42,44].…”

“…Thirteen articles explored the effect of COVID-19 on lung function at follow-up [27][28][29][30][31][32]36,37,40,41,43,45,46] (Supplementary Table S3 and Figure S2). Abnormal pulmonary function tests (PFT) were identified in 39% (95% CI 24-55, I 2 = 94%) of the patients (Table 2).…”

Importance of Lung Ultrasound Follow-Up in Patients Who Had Recovered from Coronavirus Disease 2019: Results from a Prospective Study

“…However, only a few studies have analyzed the evolution of lung lesions over time. It has been reported that fibrotic changes and ground glass opacities might persist in 20–45% of patients 3–6 months after onset of the disease [ 20 , 21 , 22 , 23 , 24 ]. These percentages vary depending on the time of follow-up and the initial severity.…”