Scientists at the University of Seville in Spain have explained a mysterious syndrome in patients with SARS-CoV-2, called silent or “happy” hypoxemia. This phenomenon consists in a noticeable decrease in the level of oxygen in arterial blood against the background of pneumonia, but patients do not suffer from shortness of breath or rapid breathing. This is reported in an article published in the journal Function, and the research is summarized in a press release on EurekAlert !.
“Happy” hypoxemia refers to a potentially dangerous event that can suddenly turn into a critical condition that is fatal. Usually, people with hypoxemia develop shortness of breath, which increases the body's oxygen consumption. This reflex mechanism depends on the work of the carotid bodies located next to the carotid artery and stimulating the work of the respiratory center.
The researchers concluded that silent hypoxemia develops when SARS-CoV-2 attacks the carotid bodies. This is indicated by the high presence of the ACE2 receptor in carotid artery cells. ACE2 serves to attach the coronavirus to the infected cell. If this hypothesis is confirmed, then activators of the carotid bodies that stimulate respiration can be used to help patients.
