There is a growing body of evidence that COVID-19 is a much more complex disease than simply a severe respiratory infection. The newest wrench in battling this deadly illness is undetected blood clots, which can cause strokes, heart attacks, and organ damage.
Researchers at Baylor College of Medicine in Houston, Texas, became aware of the problem when COVID-19 patients in the Intensive Care Unit (ICU) were experiencing unusual clotting problems. This issue was creating complications with central intravenous lines, arterial lines, and dialysis catheters.
“I’d never seen or heard anything like this in my 30 years as a surgeon, even in our sickest patients,” Dr. Todd Rosengart, chair and professor of the Michael E. DeBakey Department of Surgery at Baylor, and senior author of the paper was quoted in a press release.
Search for the Right Test
Typical tests used to determine if a person’s clotting functions include checking prothrombin time (PT), activated partial thromboplastin time (a PTT), and thrombin time (TT). A research team of seven physicians and scientists looked at twenty-one COVID-19 patients who had been admitted to the ICU at Baylor St. Luke’s Medical Center. They found that the standard clotting profile of the patients was reasonably normal. This prompted the team to determine what types of tests would identify these blood clots that would otherwise not be detected.
Blood clots consist of platelets and the protein fibrinogen. Patients’ fibrinogen levels were tested as well as their D dimer levels. (A D dimer test indicates how rapidly a patient’s clots are being broken down.)
The patients in the study had fibrinogen levels that were more than triple what is considered normal. However, the combined results of the fibrinogen levels and the D dimer levels did not indicate which patients were at risk of developing blood clots.
The test that provided researchers with the information they were looking for is called a thromboelastography (TEG) test. This test revealed that the patients who were experiencing clotting of their central IV lines, arterial lines, and dialysis catheters had abnormally high clotting function compared to patients who did not experience clotting issues. Additionally, the clot breakdown function was much higher in the patients who had less clotting.
“The test visually demonstrates the strength and rapidity of clot formation,” Rosengart tells Parentology.
The TEG test is performed for open-heart surgery patients and trauma patients. It is not routinely performed on ICU patients. Rosengart recommends that the TEG test be performed right away on all high-risk patients who test positive for COVID-19 and emphasizes that waiting for admission to the ICU, “May often be ‘after the fact’ of complications occurring.”
Test Results Allow for Earlier Treatment
In the study at Baylor, the test detected blood clots in 62% of the study’s twenty-one patients. Having these results allows for patients to be treated with anticlotting medications. According to Rosengart, patients receive “full therapeutic heparinization.”
As mentioned, blood clots can cause strokes, heart attacks, and organ damage. The research team is now looking at whether these undetected blood clots could be related to unexplained deaths seen in some COVID-19 patients.
Blood Clots and COVID 19 — SOURCES
JAMA Network Open – Thromboelastographic Results and Hypercoagulability Syndrome in Patients With Coronavirus Disease 2019 Who Are Critically Ill
Baylor College of Medicine – Test can identify undetected blood clots in COVID-19 ICU patients