As the Covid -19 pandemic is in the sixth month in India, Dr Randeep Guleria, Director of AIIMS, explains about key learnings from managing it, and new aspects that have emerged.
In the beginning, the virus was only causing respiratory infection, pneumonia. Now there are patients with blood clots; the virus is targeting the transport of oxygen, choking off its supply to other organs which means covid is becoming more of a vascular disease. When it started, it was felt it was like any other viral pneumonia: as we see with influenza, it causes predominantly upper respiratory problems and in some people it goes to the lower respiratory tract and leads to fall in oxygen saturation.
It becomes a hypercoagulable state which promotes clotting and patients are dying due to blocked blood vessals.In the beginning, it was thought ,all this wasn’t a major issue but as we see more cases, it has become an issue. So the treatment has to be holistic.
Effect on Brain?
There is not much data on this. Doctors have tried to culture the virus from Brain. Whether it causes encephalitis, where does the virus enter the brain and does it cause inflammation in the brain or whether it causes inflammation of vessels supplying blood to the brain – all these are being looked at. Probably, it is a little bit of both.
There could be viremia, the virus traveling from the blood to the brain, and causing some changes; but a large amount of effect that happens is because of vessel involvement. You can see that in patients, they are not only presenting stroke even while in the ICU and being treated for Covid-19; but it happens even later on, over the course of the disease when the viral load may have come down but the inflammation persists.
Effect on Kidney?
The kidney can fail under multiple ways; one, when we have vessel involvement, and often in advance-stage patients, (there is) septic shock which leads to a decrease in blood supply to kidney causing kidney failure. Also, found, in around one-third of patients who are critically ill — they do have acute kidney injury and require dialysis.
It has been reported from multiple places in the US and is seen in individuals, who sort of recovered and then they have a fever, hyperinflammatory syndrome which affects the skin, intestine, and has cardiac dysfunction. Many of these patients require ICU care to support blood pressure. This is a syndrome that is still evolving and mimics another similar disease,Kawasaki Disease