Pulmonary Function Among COVID-19 Patients in Home Isolation Program

Authors

Narongkorn Saiphoklang, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Pitchayapa Ruchiwit, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Apichart Kanitsap, Department of Internal Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Pichaya Tantiyavarong, Department of Clinical Epidemiology, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Pasitpon Vatcharavongvan, Department of Community Medicine and Family Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Srimuang Paluangrit, Department of Community Medicine and Family Medicine, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand
Kanyada Leelasittikul, Medical Diagnostics Unit, Thammasat University Hospital, Pathum Thani, Thailand
Apiwat Pugongchai, Medical Diagnostics Unit, Thammasat University Hospital, Pathum Thani, Thailand
Orapan Poachanukoon, Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathum Thani, Thailand

Keywords

COVID-19, Home isolation program, Pulmonary function, Small airway disease

Abstract

Introduction: Patients with mild coronavirus 2019 disease (COVID-19) are usually treated in an outpatient setting. Pulmonary functions in this setting have not been observed. This study aimed to determine abnormal lung functions in COVID-19 patients under a home isolation program.

Methods: A prospective study was conducted in COVID-19 patients with asymptomatic or mild disease at Thammasat-Khukot Medical Center and Thammasat University Hospital, Thailand, between November 2021 and May 2022. Demographics, smoking, symptoms,
pulmonary functions including forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), forced expiratory flow at 25 - 75% of FVC (FEF_25-75), and bronchodilator test were collected. Spirometry was performed after disease resolution at baseline and 3-month follow-up. Abnormal lung functions were defined as restrictive lung pattern (FVC< 80%), airway obstruction (FEV₁/FVC < 70%), small airway disease (FEF_25-75 < 65%), or bronchodilator response (increase in FEV₁ or FVC ≥ 12% and 200 mL).

Results: A total of 199 patients (56% female) were included. Mean age was 39.8 ± 15.4 years. Smoking history was 22% (6.8 ± 9.1 pack-years). Asymptomatic patients were 8.5%. Common symptoms were fever (53.5%), cough (55.0%), and dyspnea (30.5%). Abnormal lung functions were restrictive lung pattern in 15.5%, airway obstruction in 3.5%, small airway disease in 20.0%, and bronchodilator response in 3.0%. There was significant decrease in FEV₁ (40 mL), FEV₁/FVC (0.93%), and FEF_25-75 (6.7%) between baseline and 3-month follow-up. Linear regression analysis showed that age, sex, body weight, height, smoking history, and previous respiratory diseases were not associated with lung function decline.

Conclusions: Abnormal pulmonary functions, especially, small airway disease, were common among COVID-19 patients under a home isolation program. There was significant reduction in FEV₁, FEV₁/FVC, and FEF_25-75, regardless of age,sex, weight, height,smoking, and previous respiratory diseases. These findings indicate that mild COVID-19 patients might develop airway obstruction in the future.

Recommended Citation

Saiphoklang, Narongkorn; Ruchiwit, Pitchayapa; Kanitsap, Apichart; Tantiyavarong, Pichaya; Vatcharavongvan, Pasitpon; Paluangrit, Srimuang; Leelasittikul, Kanyada; Pugongchai, Apiwat; and Poachanukoon, Orapan. 2022 Pulmonary Function Among COVID-19 Patients in Home Isolation Program. Asian Medical Journal and Alternative Medicine. 22, 4 (Aug. 2022 ), Saiphoklang, N., Ruchiwit, P., Kanitsap, A., Tantiyavarong, P., Vatcharavongvan, P., Paluangrit, S., Leelasittikul, K., Pugongchai, A. and Poachanukoon, O. 2022. Pulmonary Function Among COVID-19 Patients in Home Isolation Program. Asian Medical Journal and Alternative Medicine. 22, - (Aug. 2022), S98. DOI:https://doi.org/10.14456/2022s10707.-.
Available at: https://doi.org/10.70933/2773-9465.1223

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