April 22, 2020 / By Elizabeth Cohen, CNN
(CNN) – Dr. Kathryn Hibbert’s Covid-19 patient in the intensive care unit was not doing well. As his blood pressure plummeted, she tried to insert an intravenous line into an artery in his wrist.
A blood clot clogged the tubing. 
Frustrated, Hibbert tried again with a new needle. A blood clot clogged up that line as well.
It took three tries to insert the IV.
“You just watch it clot right in front of you,” said Hibbert, director of the medical intensive care unit at Massachusetts General Hospital. “It’s rare to have that happen once, and extremely rare to have that happen twice.”
Hibbert and other doctors are finding that some patients infected with the novel coronavirus have a propensity towards developing blood clots, which can be life threatening if the clot travels to the heart or lungs.