Cause for Sudden Drop in Blood Oxygen During COVID-19 Discovered
"Silent hypoxemia" is one of the physiopathological characteristics of COVID-19 that has most baffled the scientific and medical community; still its causes are unknown. It is typically manifested as severe pneumonia with markedly decreased arterial blood oxygen levels.
However, a group of researchers from the Seville Institute of Biomedicine - IBiS/University Hospitals Virgen del Roc�o y Macarena/CSIC/University of Seville have found that these "silent hypoxemia" in COVID-19 cases could be caused by an organ - carotid bodies, upon infection by the coronavirus (SARS-CoV-2), published in the journal Function.
‘�Silent hypoxemia� is one of the physiopathological characteristics of COVID-19, may be caused due to the alterations made by the coronavirus, in the ability of the carotid body to detect blood oxygen levels. This may enable the use of activators of the carotid body independent of the oxygen sensing mechanism as respiratory stimulants in patients with COVID-19.’
Patients with COVID-19 do not report dyspnea (subjective feeling of shortness of breath) or increased breathing rates. Generally, the healthy or sick individuals with hypoxemia have shortness of breath with a higher breathing rat. This increases the body's uptake of oxygen - a reflex mechanism by carotid bodies.
Carotid bodies are small organs, located on either side of the neck next to the carotid artery, that detect the drop in blood oxygen and send signals to the brain to stimulate the respiratory centre.
Patients with these "silent hypoxemia" often suffer a sudden imbalance, reaching a critical state that can be fatal.
Silent hypoxemia in COVID-19
Experiments have proved increased levels of the enzyme ECA2, the protein used by coronavirus to infect the human cells, in the carotid body. In patients with COVID-19, the coronavirus circulates in the blood. And the virus in the early stages of the disease could alter the ability of the carotid body to detect blood oxygen levels, resulting in an inability to "notice" the drop in oxygen in the arteries.
This hypothesis has attracted the interest of the scientific community for its novelty and possible therapeutic significance that would enable the use of activators of the carotid body independent of the oxygen sensing mechanism as respiratory stimulants in patients with COVID-19.
Source: Medindia