Long-term pulmonary assessment in Iranian severe COVID-19 ICU survivors in 2020-2021: A Cohort Study

Background: Severe coronavirus infections may lead to long-term effects, such as persistent lung dysfunction and residual involvement. This study aimed to evaluate pulmonary function tests (PFT) and chest computed tomography (CT) scans of severe COVID-19 intensive care unit (ICU) survivors one year after discharge. Methods: A cohort study was conducted, assessing spirometry and chest CT scans in patients with severe COVID-19 admitted to the ICU. Patients with pre-existing lung disease were excluded. Initial laboratory tests, clinical information, and medication (antivirals and corticosteroids) were reported in patients with and without fibrosis on chest CTs. Results: Thirty patients (57% female) with a mean (SD) age of 50 (13.5) years were included. Initial pulmonary involvement had a mean score of 16 (±4), with ground-glass opacification (GGO) observed in all patients, consolidation in 88%, and pneumomediastinum in 10% of patients. One-year chest CT scans revealed mild fibrotic changes in 70% of patients, presenting as a fibrotic band (47%) or a fibrotic band with GGO (23%). Patients with fibrosis had lower serum albumin levels, lower platelet counts, and were older. One-year follow-up spirometry showed that 73% had normal results, 20% had mild obstruction, and 7% exhibited a hyperreactive airway pattern. Spirometry parameters did not significantly differ between the fibrosis and non-fibrosis groups. Conclusion: Most patients who survived severe COVID-19 infection showed significant improvement in one-year follow-up chest CT scans, and their PFT was not severely impaired. Importantly, our findings indicate no association between the severity of initial lung involvement, medication use, and follow-up chest CT results.