Explained: Why does blood clotting happen in Covid patients? How is it treated?

About Author: Dr. Devender Singh is a Consultant-Vascular & Endovascular Surgeon at Yashoda Hospitals in Hyderabad. Dr Singh is one of the first few qualified (Board certified) practicing vascular and endo vascular surgeon with special expertise in arterial as well as venous surgery. He has authored 32 articles in various national and international journals and delivered over 50 guest lectures around the globe. He is a distinguished national and international faculty and has authored 3 chapters in handbook of vascular surgery.

Covid-19 can cause blood clots, and is found in individuals who are hospitalized with extreme Covid infection. It is unclear how Covid-19 prompts blood clots. But, the disease has been found to initiate cells that are associated with the clotting process. Blood clots because of Covid-19 can prompt complications like stroke and coronary failure and this can happen across all age groups.

Blood clotting among Covid-19 patients involves a variety of organs including lungs, heart, limbs, brain, stomach and intestine, which require urgent attention. This deadly infection is identified to produce clots and the occurrence of heart attack, strokes or limb loss (due to clots) is on the rise, especially during the pandemic. Covid infection is a vascular disease, the virus damages the vessels of any of the lungs leading to clotting (thrombosis) of vessels which can lead to sudden death. The virus attacks both venous and arterial systems leading to poor outcome. A clot in the vein is called Deep Vein Thrombosis (DVT), typically identified with severe pain , redness and discoloration of skin, which can travel to the lung and cause a condition called Pulmonary Thromboembolism (PTE), which is a probable cause of sudden death.

Tingling sensation, numbness, coolness, discolouration of skin, excruciating pain in the limb with weakness and loss of pulse are alarming signs of possible Vascular clotting and hence needs to be looked for with thorough physical examination. 30-50% of moderate to severely Covid infected patients have a tendency to develop vascular clotting. He also pointed out that diabetics, smokers, hypertensive patients, pregnant ladies, immunocompromised patients, kidney failure and obese patients are more prone to the sudden clotting in the blood vessels in Covid-19 infection.

These patients carry very high risks and should be monitored carefully for the occurrence of blood clotting. In the blood investigations, increasing levels of D-Dimer, platelets, fibrinogen, indicates a high risk for blood clotting and so the physician should be careful and these patients be considered for a full dose of anticoagulation.

Prevention of blood clotting

Patients with pre-existing vascular issues or with Covid infection should take more precautionary measures such as keeping adequate hydration and active mobilization. Patients who have recovered from Covid infection are advised to continue blood thinners for at least 3 months.

For initial treatment, patients have to ensure timely referral to a vascular surgeon who can save the life and limb in these patients. Early detection of these clots can be managed with simpler procedures like embolectomy, which can be done under local anaesthesia, at bedside for very sick patients. Percutaneous procedures and thrombolysis is also an option in few cases.

Patients with moderate to severe covid infection should be discharged on anticoagulation to avoid these catastrophic events of limb loss and permanent disability.