Dr. Flynn: On the danger of a pulmonary embolism and recovery for Patriots’ David Andrews

(Adam Richins for BSJ)

Patriots veteran center David Andrews has been diagnosed with blood clots in his lungs which are called pulmonary emboli (PEs). He was treated and has been released from the hospital. I do not believe that he will return to the Patriots this season and, even after this season, a return to the NFL will be difficult.

A pulmonary embolism (PE) can come from different sources. Some break off of a deep venous clot in the leg or arm and travel to the lung, others form in the heart and travel to the lung, and some form in the lung itself. When a PE enters the blood, vessels in the lung it causes a blockage which prevents a portion of the lung from exchanging oxygen and carbon dioxide. If a PE is tiny, the patient may not even notice symptoms. However, if the PE is large, or if there are multiple PEs, the oxygen levels in the patient’s blood will drop and they begin to notice symptoms such as shortness of breath or chest pain.

A pulmonary embolism that’s big enough to cause symptoms is a medical emergency. Patients are admitted to the hospital and immediately started on blood thinners to prevent new clots from forming and to encourage the PE(s) to dissolve. Once the patient is stabilized they can be transitioned to an oral (or sometimes injectable) blood thinner that they can go home on. The hospitalization can last a few days to a few weeks, depending on how sick the patients is.

Doctors can then turn their attention figuring out why the blood clot occurred. Generally speaking, a PE is thought to be either “provoked” (there was an event that suddenly increased the risk for it to happen) or “unprovoked” (no clear reason). A few of the factors that can provoke a PE include recent surgery, a long flight, dehydration, and immobilization of the leg in a brace or splint.

For provoked PEs, treatment with anticoagulation is recommended for a minimum of 3 months, to get them through the window where they are thought to be at risk of another PE. For unprovoked blood clots, lifelong anticoagulation is considered. In studies, patients with unprovoked PEs who stop anticoagulation after 3-6 months, the risk for another clot is 10 percent in the first year after stopping blood thinners and 5% per year after.

What does this mean for David Andrews?

Andrews has had an up and down preseason. At times he appeared to be physically struggling, pausing to lean over and catch his breath. This was most notable during their week in Tennessee, where the weather was very hot and very humid. Were his symptoms an early sign of pulmonary emboli?

It’s possible that the Patriots center just attributed his shortness of breath to not yet being in regular-season shape. Or maybe he assumed his body was just sensitive to the climate. Remember when the Patriots played a game in Denver and then remained at altitude to train in Colorado Springs before facing the Raiders in Mexico City? Andrews developed an undisclosed illness while in Colorado and ended up missing the next two games. Many believed that this was an altitude illness. So you can understand why a little shortness of breath could have been brushed aside. In high-level athletes, who use their lung reserve very well, small PEs can hide themselves well and are very difficult to detect unless you’re specifically looking for them.

It is a great relief to know that Andrews is home and doing well. This means that his blood clot(s) were likely small and that he is feeling better. In general, patients are kept on blood thinners for a minimum of 3-6 months, depending on severity, whether or not the PE was thought to be provoked, and his personal decision to continue or discontinue treatment. As long as a patient is on anticoagulation medication, he cannot participate in contact sports because of the high risk of internal bleeding.

In 2017, Patriots tackle Antonio Garcia missed his rookie season with the Patriots due to a pulmonary embolism. He was released by the Patriots in May 2018 and eventually landed with the Colts. He was recently suspended the first 4 games of this season for PED use. Garcia was able to make it back to the NFL, but it has not been easy. Even if an athlete like Garcia or Andrews is taken off of blood thinners, it takes a while for the lungs to fully recover and for the athlete to return to regular-season NFL shape. While a diagnosis of a pulmonary embolism does not mean an NFL athlete’s career is over, it’s a very difficult uphill battle that few have successfully overcome.


Dr. Jessica Flynn is a sports medicine physician at Lahey Hospital and Medical Center in Burlington, MA. She writes about injuries in professional sports on her blog, You can follow her on Twitter @jessdeede.

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