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

Ayad Mohammed Salem,1 Noor Al Khathlan,2 Abdulelah Fawzi Alharbi,3 Turki Alghamdi,3 Saleh AlDuilej,3 Mohammed Alghamdi,3 Majed Alfudhaili,3 Ahmed Alsunni,1 Talay Yar,1 Rabia Latif,1 Nazish Rafique,1 Lubna Al Asoom,1 Hussein Sabit4 1Department of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 2Department of respiratory care, College of Applied Medical Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 3College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 4Department of Genetics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi ArabiaCorrespondence: Ayad Mohammed SalemDepartment of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, PO Box 2114, Dammam, 31451, Saudi ArabiaEmail ayadsalem@iau.edu.saBackground: 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 (Raw)], diffusion capacity for carbon monoxide (DLCO), 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 (FEV1), FEV1/FEV, and diffusing capacity for carbon monoxide (DLCO) 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.Keywords: COVID-19, pneumonia, PFT, DLCO, FeN