While COVID-19 has struck the world, it is crucial to understand the effects of the virus, which has made it such a severe threat. Researchers are trying to decode the reasons why acute health complications occur in severe cases.
Why Does Oxygen Level Drop in Severe Cases?
Researchers from the Icahn School of Medicine, Mount Sinai, have found out that COVID-19 results in substantial dilution in the capillaries and other blood vessels of the lungs. This tends to lower oxygen saturation drastically, ultimately leading to respiratory failure. This could be the reason why COVID-19 is far more different from typical acute respiratory distress syndrome (ARDS).
Oxygen level drops in classical ARDS when pulmonary inflammation causes fluid to accumulate in the lungs, which in turn reduces the blood-oxygen saturation drastically. However, in COVID-19, patients who experience hypoxia (low level of oxygen in the blood) usually show a disproportionate degree of lung stiffness. This indicates that the mechanism of hypoxia in COVID-19 might be different from that of acute respiratory distress syndrome (ARDS).
Initially, the scientists were actually conducting a study on cerebral blood flow in patients seeking mechanical or assistive ventilation. They used a fully-autonomous robotic TCD (transcranial Doppler) system – The Lucid Robotic System by NovaSignal.
Senior author of the study, Hooman Poor, MD, Assistant Professor of Medicine at the Icahn School of Medicine, Mount Sinai and Director of Pulmonary Vascular Disease, stated:
In this study, scientists injected saline with microbubbles into the COVID-19 patients’ veins. The robotic transcranial Doppler system was then used to determine if these microbubbles appeared into the blood vessels of the brain. In a healthy person, these microbubbles are carried to the right side of the heart. They then enter the pulmonary blood vessels and get filtered by the capillaries. This happens because the diameter of the microbubbles is greater than that of the capillaries.
However, suppose the microbubbles somehow enter the blood vessels in the brain, it indicates that either the person has a hole in the heart or the diameter of the pulmonary capillaries is abnormally large, allowing the bubbles to pass through.
The pilot study was conducted on 18 patients, out of which 83% had microbubbles in the blood vessels of the brain. This indicated the presence of dilating pulmonary blood vessels in these mechanically ventilated people. Furthermore, the number of microbubbles detected shows that the dilations of pulmonary blood vessels explain the disproportionate hypoxemia in severe COVID-19 cases.
After the initial study, the research was expanded to about 80 patients showing low-to-severe symptoms. This will help the team to understand how the microbubbles transit in varying severity of the disease.
A detailed report on the findings has been published in the American Journal of Respiratory and Critical Care Medicine.
COVID-19 Vaccine Update
A piece of news stating that the Serum Institue of India will launch the vaccine in 73 days was surfacing the internet a few hours ago. However, SII has issued a clarification, denying any such report.
As per reports from ANI, SII has stated that the vaccine, Covishield, will be commercialized only once trials are successful and regulatory approval has been granted. SII will confirm the availability once the efficacy of the vaccine is established. As for now, the government has allowed SII to manufacture the vaccine and stock it up for the future.