How Do the Aerosols of Coronavirus Cause Hypoxia (low oxygen in tissues)?

Inhalation of isolated coronavirus particles allows more than 65% of them to reach the deepest region of our lungs (upper and lower right lung more than the left) where damage to cells can lead to low blood oxygen levels, as per a study "SARS CoV-2 aerosol: How far it can travel to the lower airways" at the University of Technology, Sydney, published in the journal Physics of Fluids.

"Our lungs resemble tree branches that divide up to 23 times into smaller and smaller branches. Due to the complexity of this geometry it is difficult to develop a computer simulation, however we were able to model what happens in the first 17 generations, or branches, of the airways. Depending on our breathing rate, between 32% and 35% of viral particles are deposited in these first 17 branches. This means around 65% of virus particles escape to the deepest regions of our lungs, which includes the alveoli or air sacs," says Dr. Saidul Islam, from the University of Technology Sydney.

‘Inhalation of isolated coronavirus particles allows more than 65% of them to reach the deepest region of our lungs (right lung more than the left) where damage to cells can lead to low blood oxygen levels (hypoxia). It is thereby important to develop targeted drug delivery devices that would allow the drugs to reach the targeted position of the lower airways. ’

The ability to absorb oxygen critically depends upon the alveolar system (terminal branches) of the lungs. Viral inflammation can severely damage this region thereby causing hypoxia followed by an increased risk of death.

Why Aerosols are Serious in COVID-19?

The reason why more virus particles are deposited in the right lung is due to the highly asymmetrical anatomical structure of the lungs and the flow of air through it. The study team had created a model of three different flow rates - 7.5, 15, and 30 liters per minute.

They had observed that the model had shown greater virus deposition at lower flow rates. The study also implicates the development of targeted drug delivery devices. This may allow the drugs to reach the targeted position of the lower airways, especially with diseases like COVID-19, and understand how SARS CoV-2 aerosols affect individual patients.

The aerosols from a diseased person have more potency to infect those nearby. Hence the World Health Organisation recently updated its advice about the importance of aerosol transmission, warning that because aerosols can remain suspended in the air, crowded indoor settings and areas with poor ventilation pose a significant risk for transmission of Covid-19.

The study further seeks to apply portable devices (that measures the concentration of pollutants and various gases in air) to model the impact of these on our lungs.

Source: Medindia