PHYSICAL CAPACITY AND TISSUE OXYGENATION IN POST-COVID-19 PATIENTS
Exercise Tolerance; Coronavirus Infections;
Spectroscopy, Near-Infrared
Introduction: Scientific and clinical evidence points to a persistent impairment of physical capacity in post-COVID-19 individuals. Such residual effects may persist for months and may be influenced by the severity of the infection and the need for hospital admission and use of ventilatory support.
Objective: To assess physical capacity in addition to analyzing the behavior of tissue muscle oxygenation during exercise capacity tests in post-COVID-19 patients.
Methodology: This is a cross-sectional study in patients diagnosed with COVID-19 who were hospitalized or not, aged over 18 years of both sexes. We compared the performance and responses of vastus lateralis oxygenation during the one-minute sit-and-stand test (1-STS) and the
Six-Minute Walk Test (6MWT) in 20 people who were hospitalized (COVID-I), in 16 people who did not require hospitalization (COVID-NI) and11controls.NIRS-(PortamonArtinisMedicalSystems,BV,
Netherland) near-infrared spectroscopy signals (oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), total hemoglobin (tHb) and tissue saturation index (TSI) of vastus lateralis were recorded before, during and two minutes after the tests (recovery). Data were presented as median and interquartilerange,forintra group comparisons of variables were performed using Friedman while intergroup comparisons by Kruskal-Wallis using the statistical program Graph Pad Prism 8.0 (GraphPad Software Inc SanDiego California, USA) with significance levelsp<0.05 and a 95% confidence interval.
Results:There was a statistically significant difference in the performance of COVID-I9 compared to COVID-NIandthecontrol (p<0.0001) in the 6MWT. Such difference was not observed in 1-STS. Despite lower performance, post-COVID-19 versus control patients showed no differences between NIRS variables during testing and recovery.
Conclusion: The 6MWT was able to prove a difference in performance between the groups and seems to be more efficient in detecting lower functional capacity in post-COVID-19 patients when compared to the 1-STS. Despite the performance differences, post-COVID-19 patients