International studies have shown that the increase in blood pressure known as deep vein thrombosis (DVT) in Covid-19 patients in hospitals is 14-28%.
Covid 19: There is growing evidence to suggest that COVID-19 is not only a lung disease as previously thought but also can cause dangerous blood clots that need to be removed immediately to save organs in some cases, experts say.
International research has shown that the increase in blood pressure known as deep vein thrombosis (DVT) in COVID-19 patients in hospitals is 14-28% and is 2% lower in arterial thrombosis.
India’s experience is similar, experts say, emphasizing that the infection is as common in the blood vessels as the lungs.
We deal with five such cases a week on average. This week marked one day of such problems, said Dr Ambarish Satwik, a vascular surgeon at Sir Ganga Ram Hospital in Delhi.
The prevalence of blood clotting in COVID-19 is high in patients with conditions such as Type 2 Diabetes Mellitus, although the disease may not be known, added Dr. Amrish Kumar, coordinator, cardio-thoracic vascular department, Aakash Healthcare southwest of Delhi Dwarka Area.
While DVT is the most serious condition that occurs when a blood clot is inserted into a deep vein, arterial thrombosis is a clot that grows in a vein. Arteries are blood vessels that carry oxygen-rich blood from the heart to the body, while the arteries carry oxygen-rich blood from the body to the heart.
Satwik referred to a Covid-clot link in a tweet earlier this week in which he posted a picture of blood drawn from the veins of a COVID-19 patient’s lower limbs.
What Covid clots look like. Covid produces blood clots. The incidence of a heart attack, or organ loss due to vascular obstruction in Covid varies from 2 to 5 percent. We have removed this from the Covid patient’s lower extremities. We were able to save the limb, Mr Satwik said on May 5.
Explaining his tweet, which attracted a lot of attention and questions as well, Mr Satwik said the patient’s COVID-19 was severely restricted to blood circulation due to clots, the organ was threatened.
So we had to undergo a physical operation to remove the tumors, otherwise there would have been a serious wound, and he would have been amputated. We were able to successfully remove the clots and preserve the organ, explains the surgeon.
Authors of a Lancet paper published in November last year said studies suggested there is an increased association between COVID-19 and the risk of thromboembolism (TE) or obstruction of a blood vessel by a blood clot.
The authors of the paper concluded that TE rates of COVID-19 are high and associated with a higher risk of death.
We have been understanding the pathophysiology of COVID-19 for over a year now. When it first hit China and the global west, it was thought that it was typical viral pneumonia. Severe cases of acute COVID-19 were being labelled as similar to the acute respiratory distress syndrome (ARDS), which leads to respiratory failure, Satwik noted.
However, a series of post-mortem examinations of COVID-19 patients and their lungs revealed that what the doctors saw was not standard ARDS.
…moreover, they were getting clots in the microcirculation of the lungs. It was therefore well understood that COVID is as common as cardiovascular disease as pneumonia, adds Satwik.
In a patient with COVID-19, where the blood vessels are damaged, it produces a protein that attracts platelets and other clotting factors, Mr. Kumar added.
Studies have shown that about 20 to 30 percent of patients in COVID-19 hospitals have developed this problem, he told PTI.
Because blood vessels are everywhere in the body, these clots can form anywhere, says Satwik. Some of these clusters have large blood vessels and become large blood clots.
But otherwise we see small clusters scattered throughout the small circulation of organs in various organs, he noted.
According to a University of Oxford study published in April, the risk of abnormal blood pressure following COVID-19 is almost 100 times higher than normal.
The research found that the rare blood clotting known as cerebral venous thrombosis (CVT) — a blood clot of a cerebral vein in the brain — is more common after COVID-19 than in any of the comparison groups, with 30 per cent of these cases occurring in the under 30s.
The study covered 500,000 COVID-19 patients. The risk would be 39 in a million, according to its finding.
The signals that COVID-19 is linked to CVT, as well as portal vein thrombosis a clotting disorder of the liver is clear, and one we should take note of, said Oxford’s Maxime Taquet, one of the authors of the study.
Explaining how the virus causes blood clots in COVID-19 patients, Satwik said the virus is known to attach itself to the inner lining of the lung, and right next to these air sacs are very thin blood vessels or capillaries.
The virus invades these blood vessels and starts affecting the inner lining of these blood vessels which produces a dysfunction within the blood vessels which produces these clots, the surgeon said.
As a result, he said, some clinicians were using blood thinners as part of the treatment and getting success.
What we have understood is these micro clots need immediate retrieval in order to save the limbs, Satwik added.
He also said it is very difficult to know the prevalence of clots in the entire population infected with COVID-19.
Although it is difficult to determine the vulnerability of COVID-19, individuals with existing cardiovascular morbidities are the ones who will suffer thrombotic complications, Satwik said.
According to Kumar, in COVID-19 patients, the clots seem to form in the tiny vessels of the lungs rather than the major vessels, adding that clots in the lungs usually happen in the case of typical strokes or heart attacks or deep vein thrombosis.
Risk of COVID-19 patients associated with blood clots are stroke (clot in the cerebral artery), clots in the lungs, heart attack, deep vein thrombosis, and thrombosis in both upper and lower limb arteries. Stroke can cause paralysis, but we have not seen any such so far in our hospital, Mr Kumar added.