Quantification of post-COVID-19 symptoms and pulmonary functional capacity in children with COVID-19.

Background: Children with coronavirus disease 2019 (COVID-19) present with mild but persistent pulmonary disease. Limited studies have explored post-infection aerobic capacity and quantification of symptoms. This study aimed to quantify post-COVID-19 fatigue, dyspnea, and pulmonary functional capacity while exploring associated factors.

Methods: This prospective cohort study enrolled 6-12-year-old children with COVID-19. Participants' parents completed questionnaires assessing post-COVID-19 fatigue (Pediatric Quality of Life Inventory Multidimensional Fatigue Scale, including general, sleep, and cognition, with high scores indicating less severity) and dyspnea (Modified Medical Research Council Dyspnea Scale). Six-minute walk tests (6MWT) were performed with records of distances to assess pulmonary functional capacity.

Results: This study enrolled 21 children with seven (33 %) exhibiting persistent symptoms post-COVID-19 infection. These children had a lower COVID-19 vaccination rate (57 % vs. 100 %, p = 0.026) and a reduced sleep-related fatigue scale (69.0 vs. 80.4, p = 0.043) than those without persistent symptoms. Nineteen children performed the 6MWT achieving a mean distance of 623 m (standard deviation, SD: 231) and a mean Z-score of 2.8 (SD: 1.4). Linear regression analysis identified older age as a risk factor for fatigue (β-coefficient -0.45, p = 0.040), and the cognitive fatigue scale correlated with the Z-score of the 6MWT distances (β-coefficient: -0.56, p = 0.013).

Conclusion: Children with post-COVID-19 symptoms had lower vaccination rates and higher sleep-related fatigue levels. Older children experienced more severe fatigue and the performance of 6MWT correlated with cognition-related fatigue scale.