Thick Blood May Lead to COVID-19 Complications

After noticing unusual blood clotting in many patients diagnosed with COVID-19,

doctors believe there may be a connection to the thickness of their blood, known as hyperviscosity, with inflammation and clotting. “It has been a mystery why so many patients with COVID-19 have had atypical blood clots. We realized we needed to think beyond our typical testing strategies to understand why this might be happening,” says lead author Cheryl Maier, assistant professor of coagulation and transfusion medicine in the Pathology and Laboratory Medicine department at Emory School of Medicine and medical director of the Special Coagulation Laboratory. “Blood needs to flow smoothly for proper circulation throughout the body. Imagine the difference between something flowing like molasses or honey, instead of like water.”

The correspondence, which links hyperviscosity and severity of illness, appears in The Lancet.

The researchers tested plasma viscosity (thickness of blood plasma) in 15 critically ill COVID-19 patients with pneumonia who were admitted to Emory Healthcare intensive care units (ICUs). 

All of them had plasma viscosity levels above the normal range. The sickest patients had the highest plasma viscosity, more than double normal levels, and were also more likely to have a blood clot.