Oxygen Requirement and Associated Risk Factors in Post-COVID-19 Patients Admitted to a Tertiary Care Center: A Cross-Sectional Study.

Background: COVID-19 commonly affects the lungs and may lead to mild to severe hypoxemia. The supplemental oxygen requirement gradually reduces with the improvement in lung pathology. However, a few patients may have exertional desaturation, and ongoing oxygen needs at the time of hospital discharge. The objective of this research was to study the requirement of oxygen therapy in the immediate post-COVID-19 period and its associated risk factors.

Materials And Methods: An analytical cross-sectional study was conducted on the admitted post-COVID-19 patients who had recently tested real-time polymerase chain reaction (RT-PCR) negative in a tertiary care center from August 2021 to mid of October 2021. Nonprobability consecutive sampling was used, and the sample size was 108. The data were analyzed using the Statistical Package for the Social Sciences (IBM-SPSS), version 23. The mode of oxygen therapy (nasal cannula, face mask, reservoir mask, or mechanical ventilation) in the first two weeks of the study was presented appropriately in a table. The nonparametric statistical tests were applied to determine the association between the duration of post-COVID-19 oxygen therapy and several other risk factors such as age, gender, comorbidities, smoking status, exposure to firewood, COVID-19 vaccination, and severity of COVID-19.

Results: 95 (87.96%) cases required oxygen therapy in their immediate post-COVID-19 period. The overall median duration of oxygen therapy was 6.00 (4.00-10.00) days. The nasal cannula was the most commonly used mode of oxygen supplement. The duration of oxygen therapy was significantly higher in patients aged more than 60 years (6.00 [5.00-11.00],  = 0.013), chronic obstructive pulmonary disease (10.00 [6.00-12.75],  = 0.006), history of chronic smoking (9.00 [5.50-13.00],  = 0.044), and severe COVID-19 infection (7.00 [5.00-10.50],  = 0.042).

Conclusions: The proportion of patients requiring oxygen therapy in the immediate post-COVID-19 period was higher than that reported in other studies. In addition, old age (>60 years), chronic obstructive pulmonary disease, chronic smoking, and severe COVID-19 infection significantly increased the duration of oxygen therapy. So, these factors should be assessed while discharging patients from COVID-19 facilities, and oxygen supplementation should be planned for needy patients.