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.