Baylor Study Recommends TEG Tests to Identify Clot Risk in ICU Patients With COVID-19

June 5, 2020—Baylor College of Medicine announced the publication of findings supporting the use of thromboelastography (TEG) to test for the risk of forming blood clots in patients with COVID-19 admitted to an intensive care unit (ICU). The investigators recommended the use of TEG after determining that more than half of the patients tested under these conditions developed clinically significant blood clots that went undetected using routine screenings.

Jared Robert Mortus, MD, et al published the research letter online in the Journal of the American Medical Association open network. The investigators are from the Baylor College of Medicine and the Michael E. DeBakey VA Medical Center in Houston Texas. Todd Rosengart, MD, who is chair and professor of the Michael E. DeBakey Department of Surgery at Baylor, is the senior author of the paper.

“As the surgical critical care team at Baylor St. Luke’s Medical Center was discussing their work in the ICU a few weeks ago,” commented Dr. Rosengart. “I was amazed to hear them express that one of their greatest challenges was that the central intravenous and arterial lines and the dialysis catheters kept unexpectedly clotting in COVID-19 patients in the ICU. I’d never seen or heard anything like this in my 30 years as a surgeon, even in our sickest patients.” This caused Dr. Rosengart and colleagues to look at what types of tests could be performed to identify these otherwise undetected blood clots.

As reported in the Baylor announcement, the investigators observed 21 patients with confirmed COVID-19 infection admitted to the Baylor St. Luke’s Medical Center ICU between March 15 and April 9. They found that the standard clotting profile or screening of the patients was fairly normal. The patients were then moved to the next level of more specific clotting tests, which included analyzing a patient’s fibrinogen and D dimer levels.

For the COVID-19 patients in the ICU, the levels of fibrinogen were more than three times the normal range, indicating that the body was churning out this protein. Looking at these two results together, there was no clear indication that these patients were at increased risk of forming blood clots.

The investigators then looked to TEG tests, which are not regularly used in most ICU patients, to evaluate how quickly a clot forms and its strength and stability.

The TEG test showed (1) the patients who were clotting their central intravenous and arterial lines and dialysis catheters had abnormally high clotting function compared with the patients who did not have clotting issues; and (2) the clot breakdown function was significantly higher in the patients who were clotting less than others. Thirteen (62%) of the 21 patients in the study developed 46 blood clots that could only be detected through the TEG test.

For patients who are at a higher risk of blood clots as indicated by the TEG test, the investigators recommend administering additional blood thinners. They are now looking at whether these undetected blood clots could be related to the unexplained deaths they are seeing in COVID-19 patients.

In the Baylor announcement, Dr. Rosengart concluded, “The TEG test should be performed on all COVID-19 ICU patients immediately to find those who are at a higher risk of clotting. At the point where physicians discover that their central line and catheter is clotting, the horse is out of the barn.”

This study follows an American College of Surgeons (ACS) announcement on May 15 of the publication of a study by Franklin L. Wright, MD, et al online in Journal of the American College of Surgeons that also used TEG to determine that critically ill patients infected with COVID-19 were at high risk for developing renal failure, venous blood clots, and other complications associated with blood clots, such as stroke. Those investigators are from the University of Colorado Anschutz Medical Campus in Aurora, Colorado.