What are the pathophysiological mechanisms of exercise limitation and hyperventilation in patients recovering from COVID-19 at hospital discharge?
Exercise limitation in COVID-19 survivors at hospital discharge is primarily driven by peripheral factors (myopathy and anemia) and enhanced chemoreflex sensitivity rather than pulmonary vascular pathology.
At the time of hospital discharge, patients with COVID-19 present with reduced functional capacity and exercise hyperventilation. Peripheral factors, namely reduced oxygen extraction (myopathy) and anemia, which are not fully compensated by a supernormal cardiac output response, account for exercise limitation before exhaustion of the respiratory reserve. Enhanced chemoreflex sensitivity, rather increased dead space, mainly accounts for exercise hyperventilation. The pulmonary vascular response to exercise circulation of survived patients with COVID-19 does not present major pathological changes.
Baratto et al. (Thu,) studied this question.