ABSTRACT
Fatigue is a common, debilitating, and poorly understood symptom post-COVID-19. We sought to better characterize differences in those with and without post-COVID-19 fatigue using cardiopulmonary exercise testing. Despite elevated dyspnoea intensity ratings, VÌO2peak (ml/kg/min) was the only significant difference in the physiological responses to exercise (19.9 ± 7.1 fatigue vs. 24.4 ± 6.7 ml/kg/min non-fatigue, p = 0.04). Consistent with previous findings, we also observed a higher psychological burden in those with fatigue in the context of similar resting cardiopulmonary function. Our findings suggest that lower cardiorespiratory fitness and/or psychological factors may contribute to post-COVID-19 fatigue symptomology. Further research is needed for rehabilitation and symptom management following SARS-CoV-2 infection.
Subject(s)
COVID-19 , Cardiorespiratory Fitness , Cardiorespiratory Fitness/physiology , Exercise Test , Fatigue/etiology , Humans , SARS-CoV-2ABSTRACT
The purpose of this study was to examine the physiological mechanisms of persistent dyspnoea in COVID-19 survivors. Non-critical patients (nâ¯=â¯186) with varying degrees of COVID-19 severity reported persistent symptoms using a standardized questionnaire and underwent pulmonary function and 6-minute walk testing between 30 and 90 days following the onset of acute COVID-19 symptoms. Patients were divided into those with (nâ¯=â¯70) and without (nâ¯=â¯116) persistent dyspnoea. Patients with persistent dyspnoea had significantly lower FVC (pâ¯=â¯0.03), FEV1 (pâ¯=â¯0.04), DLCO (pâ¯=â¯0.01), 6-minute walk distance (% predicted, pâ¯=â¯0.03), and end-exercise oxygen saturation (pâ¯<â¯0.001), and higher Borg 0-10 ratings of dyspnoea and fatigue (both pâ¯<â¯0.001) compared to patients without persistent dyspnoea. We have shown that dyspnoea is a common persistent symptom across varying degrees of initial COVID-19 severity. Patients with persistent dyspnoea had greater restriction on spirometry, lower DLCO, reduced functional capacity, and increased exertional desaturation and symptoms. This suggests that there is a true physiological mechanism that may explain persistent dyspnoea after COVID-19.