Radiological and functional lung sequelae of COVID-19: a systematic review and meta-analysis

Abstract

Background The coronavirus disease 2019 (COVID-19) causes a wide spectrum of lung manifestations ranging from mild asymptomatic disease to severe respiratory failure. We aimed to clarify the characteristics of radiological and functional lung sequelae of COVID-19 patients described in follow-up period. Method PubMed and EMBASE were searched on January 20th, 2021 to investigate characteristics of lung sequelae in COVID-19 patients. Chest computed tomography (CT) and pulmonary function test (PFT) data were collected and analyzed using one-group meta-analysis. Results Our search identified 15 eligible studies with follow-up period in a range of 1–6 months. A total of 3066 discharged patients were included in these studies. Among them, 1232 and 1359 patients were evaluated by chest CT and PFT, respectively. The approximate follow-up timing on average was 90 days after either symptom onset or hospital discharge. The frequency of residual CT abnormalities after hospital discharge was 55.7% (95% confidential interval (CI) 41.2–70.1, I2 = 96.2%). The most frequent chest CT abnormality was ground glass opacity in 44.1% (95% CI 30.5–57.8, I2 = 96.2%), followed by parenchymal band or fibrous stripe in 33.9% (95% CI 18.4–49.4, I2 = 95.0%). The frequency of abnormal pulmonary function test was 44.3% (95% CI 32.2–56.4, I2 = 82.1%), and impaired diffusion capacity was the most frequently observed finding in 34.8% (95% CI 25.8–43.8, I2 = 91.5%). Restrictive and obstructive patterns were observed in 16.4% (95% CI 8.9–23.9, I2 = 89.8%) and 7.7% (95% CI 4.2–11.2, I2 = 62.0%), respectively. Conclusions This systematic review suggested that about half of the patients with COVID-19 still had residual abnormalities on chest CT and PFT at about 3 months. Further studies with longer follow-up term are warranted.

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.…”

“…These percentages vary depending on the time of follow-up and the initial severity. Residual lung injuries in COVID-19 may exceed those seen in Middle East respiratory syndrome-related coronavirus (MERS-CoV) [ 21 ].…”

“…Regarding pulmonary functional tests in the follow-up, alteration of the diffusion capacity of carbon monoxide is the most frequently described abnormality [ 21 ], which is associated with an interstitial or lung microvasculature involvement. This might correspond to microthrombus of small-caliber pulmonary arteries, as shown in autopsies [ 27 ].…”

COVID‐19 pneumonia can cause irreversible lung damage in dermatomyositis with pre‐existing interstitial lung disease

“…Our present case suggests that COVID‐19 pneumonia can cause irreversible lung damage and critically affect the quality of life of patients with dermatomyositis with pre‐existing interstitial lung disease. Recent studies have reported that half of the survivors of COVID‐19 showed residual lung damage on chest computed tomography at 3‐month follow‐up 2 . Not only SARS‐CoV but also MERS‐CoV were reported to cause irreversible lung damage in survivors 3 .…”

“…Not only SARS‐CoV but also MERS‐CoV were reported to cause irreversible lung damage in survivors 3 . This nature of coronavirus is obviously distinct from other viruses such as influenza virus which usually show complete radiologic resolution of pneumonia after treatment 2 . How is COVID‐19 pneumonia pathologically different from other virus‐related pneumonias?…”