- Decreased arterial blood oxygen levels is known as hypoxemia
- COVID-19 patients with silent hypoxemia often suffer a sudden imbalance
- Normally individuals with hypoxemia report a feeling of shortness of breath
Washington: One of the physiopathological characteristics of COVID-19 that has most baffled the scientific and medical community is what is known as “silent hypoxemia” or “happy hypoxia”. A recent study sheds light on the explanation for the lack of blood oxygenation detected in many COVID-19 patients. The study was published in the journal function. Patients suffering this phenomenon, the causes of which are still unknown, have severe pneumonia with markedly decreased arterial blood oxygen levels (known as hypoxemia). However, they do not report dyspnea (subjective feeling of shortness of breath) or increased breathing rates, which are usually characteristic symptoms of people with hypoxemia from pneumonia or any other cause.
Patients with “silent hypoxemia” often suffer a sudden imbalance, reaching a critical state that can be fatal. Normally, individuals (healthy or sick) with hypoxemia report a feeling of shortness of breath and a higher breathing rate, thus increasing the body’s uptake of oxygen. This reflex mechanism depends on the carotid bodies. These small organs, located on either side of the neck next to the carotid artery, detect the drop in blood oxygen and send signals to the brain to stimulate the respiratory centre.
A group of researchers from the Seville Institute of Biomedicine – IBiS/University Hospitals Virgen del Rocio y Macarena/CSIC/the University of Seville, led by Dr Javier Villadiego, Dr Juan Jose Toledo-Aral and Dr Jose Lopez-Barneo, specialists in the physiopathological study of the carotid body, have suggested in the journal Function, that “silent hypoxemia” in COVID-19 cases could be caused by this organ being infected by the coronavirus (SARS-CoV-2).
This hypothesis, which has attracted the interest of the scientific community for its novelty and possible therapeutic significance, comes from experiments that have revealed a high presence of the enzyme ECA2, the protein the coronavirus uses to infect human cells, in the carotid body. In patients with COVID-19, the coronavirus circulates in the blood. Therefore, researchers suggest that infection of the human carotid body by SARS-CoV-2 in the early stages of the disease could alter its ability to detect blood oxygen levels, resulting in an inability to “notice” the drop in oxygen in the arteries. If this hypothesis, which is currently being tested in new experimental models, is confirmed, this would justify the use of activators of the carotid body independent of the oxygen sensing mechanism as respiratory stimulants in patients with COVID-19.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.[corona_data_new]