Blood clot risk seen in Covid-19 patients
Experts here concerned by emergence of such cases even among young adults
Not even healthy young adults are spared from complications linked to the coronavirus, with some of those infected suffering strokes due to blood clots in their brains.
This revelation comes as doctors worldwide come to terms with a startling number of coronavirus patients with clots developing in their blood vessels. Some of them have even died.
Experts here told The New Paper that they are concerned by the emergence of such cases.
A recent study by researchers in the Netherlands showed that 31 per cent of patients in intensive care experienced thrombotic complications arising from clots in the blood vessels, supporting similar findings in Wuhan, China, from earlier in February.
Dr Lim Lay Cheng, a haematologist at the Blood Specialist Clinic in Gleneagles Medical Centre, said: "This is an unusual thing that is happening.
"Somehow with Covid-19, we see a higher incidence of clotting issues than with other viral infections.
"The worrying thing is, previously we thought only those who are severely ill would present such issues, but now we also have young adults getting it."
She was referring to a report published in the US two weeks ago that detailed five cases of patients in their 30s and 40s who suffered strokes due to blood clots.
Strokes are uncommon in younger adults.
Of the five patients, all of whom had only mild coronavirus symptoms and no risk factors for strokes, one died.
Dr Daryl Tan, a haematologist, said some affected patients also suffered heart attacks, while others had pulmonary embolism, a blockage of an artery in the lung that arrests breathing.
There have been at least three cases of people infected with the coronavirus here dying from heart problems, with the latest being a 44-year-old Bangladeshi man who died of a heart attack on Tuesday.
Pulmonary embolisms can be just as fatal - blood clots lodged within an artery in the lungs deprive it of oxygen, potentially suffocating patients, Dr Lim said.
IMPEDE FLOW OF OXYGEN
Citing the example of US actor Nick Codero, she added that blood clots that impede the flow of oxygen to the arms and legs will also cause those body parts to die. The Broadway star suffered clotting issues in his right leg and had to amputate it a few weeks into his fight against the virus.
Dr Tan, who practises at Mount Elizabeth Novena Hospital, said similar blood clotting issues were observed among some Singaporean patients with the severe acute respiratory syndrome (Sars) in 2003.
But the incidence of such cases among Sars patients was lower than what is observed today, he said.
Although the reason for this remains a mystery, experts suspect the coronavirus can trigger an overzealous immune response called a cytokine storm that turns the body against itself.
Dr Tan told TNP: "Cytokines are chemicals that act as a protective mechanism, but this virus may be activating them too much, causing the body to be inflammed.
"This leads to inflammation in the blood vessels and so clots form."
It is also possible that the coronavirus itself attacks blood vessel walls and causes them to swell, Dr Lim said.
To stop clots from getting bigger, doctors administer blood thinners to affected patients.
They have to manage the dose carefully because using blood thinners carry the risk of internal bleeding.
Dr Lim suggested using blood thinners more proactively for coronavirus patients in critical care if they are not assessed to have a high bleeding risk.
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