The Long-Term Impact of COVID-19 Pneumonia on the Pulmonary Function of Survivors

Background: The sequelae of COVID-19 pneumonia on pulmonary function and airways inflammation are still an area of active research. Objective: This research aimed to explore the long-term impact of COVID-19 pneumonia on the lung function after three months from recovery. Methods: Fifty subjects (age 18– 60 years) were recruited and classified into two groups: the control group (30 subjects) and the post-COVID-19 pneumonia group (20 patients). Pulmonary function tests, spirometry, body plethysmography [lung volumes and airway resistance (R aw )], diffusion capacity for carbon monoxide (DL CO ), and fractional exhaled nitric oxide (FeNO), were measured after at least 3 months post-recovery. Results: Significant reduction in total lung capacity (TLC), forced vital capacity (FVC), forced expiratory volume (FEV 1 ), FEV 1 /FEV, and diffusing capacity for carbon monoxide (DL CO ) was observed in post-COVID-19 subjects compared to controls. Restrictive lung impairment was observed in 50% of post-COVID-19 cases (n = 10) compared to 20% in the control group (n = 6, P = 0.026). In addition, mild diffusion defect was detected in 35% (n = 7) of the post-COVID-19 group compared to 23.3% (n = 7) in the controls ( P = 0.012). Conclusion: COVID-19 pneumonia has an impact on the lung functions in terms of restrictive lung impairment and mild diffusion defect after three months from recovery. Therefore, a long-term follow-up of the lung function in post-COVID-19 survivors is recommended.