Hypoxemia in COVID-19
Silent hypoxemia in COVID-19 was initially described in elderly patients
but shortly was reported in younger, previously healthy individuals(1).
Although perplexing at first glance, silent hypoxemia can be elucidated
through the lens of the basic principles of respiratory physiology(2).
In contrast, normocapnia until later stages of the disease is less
understood(3). With progressive hypoxemia, increased minute ventilation
and cardiac output occur as a compensatory mechanism. As the ventilatory
response is limited due to normocapnia, the cardiovascular system
becomes the central adaptive mechanism. Its failure to compensate is the
proximal cause of tissue injury in profound hypoxemia(4).