Thin blood: A delicate balance

I was at the hospital late last night. A 55-year-old gentleman who was here on vacation hit his eyelid with a paper clip, and it had swollen to the size of a football. The eyelids were full of blood and very tense. They were so tight that we couldn’t open the eyes at all. I was concerned that all the swelling might be choking off the blood supply to the eye and the eye could lose all its vision.

How could someone get into so much trouble from a paper clip? The answer lies in this man’s heart. He had a heart valve replaced several years ago. One of the miracles of modern medicine is that we can stop a beating heart, keep the person alive while the heart is stopped, replace a diseased valve, and then restart the heart and help the person live a normal life. One of the things that make this possible is the existence of a blood thinner called “Coumadin.” You see, when we put something foreign into the body, like an artificial heart valve, the body forms clots around it. A clot in a beating heart can break loose and fly off into other parts of the body like the brain, causing strokes or even death. So, by prescribing blood thinners, we can prevent the clots from forming and prevent the strokes and other problems associated with loose clots. If you have one of these types of heart valves, you need to be on a blood thinner the rest of your life. The blood thinner keeps you alive, as much as the new valve does.

Of course, clotting is a natural thing. If you didn’t clot at all, you would bleed to death from the tiniest cut. The bleeding just wouldn’t stop until you ran out of blood. Clotting is part of the design of your body to keep you from bleeding to death. Some people have genetic deficiencies in clotting, and so they have a tendency to bleed. This is called “hemophilia.” People with hemophilia can have severe bleeding even with minor injuries, because their blood doesn’t clot normally. When we use blood thinners, we are causing, in essence, a form of hemophilia. We’re interfering with the blood’s natural ability to clot.

When we use blood thinners, we need to strike a delicate balance. We need the blood to be thin enough so clots don’t form easily, but not so thin that the person will bleed from minor trauma or bleed spontaneously. We can measure the clotting times of the blood and we must monitor them carefully to keep the balance between bleeding and clotting. The clotting times need to be monitored on an ongoing basis.

Heart valves aren’t the only reason people are placed on blood thinners. Some people have a tendency to form clots deep in their veins (“deep venous thrombosis”), which can then fly off to the lungs and cause breathing problems and death (“pulmonary embolism”). So these people need blood thinners too. We also use a very mild blood thinner—aspirin—to make the blood less sticky and help prevent blood clots around the heart and brain (which cause heart attacks and strokes). We recommend aspirin and other mild blood thinners to almost all of our patients that have some risk of heart disease. But these mild blood thinners don’t need to be monitored routinely.

When I saw the massive injury this man sustained from a tiny paper clip, I immediately suspected that the balance had been lost—that the blood was too thin. When we checked the blood, we found that it was so thin that it was taking 20 times longer than normal to clot. The gentleman had simply stopped going to the doctor and was no longer having his blood monitored regularly. The blood had become very thin, and a simple trauma caused a massive injury.

Because of the severity of the problem, and the risk to many parts of his body, I involved five other doctors, including his doctor in his home country, and the gentleman’s family in making decisions about his care. We did an emergency CT scan of the eyes to make sure that there was no bleeding behind them, which could choke them off very quickly. We gave a transfusion of clotting factors so that the blood could clot again and decrease his risk of spontaneous bleeding. During the time that the blood was too thin, even a tiny bump on the head could have led to a massive bleeding inside the brain. His sight is still in danger. But for now, his clotting times are controlled and he is safe enough to travel home. If you are on a blood thinner like Coumadin, make sure you are getting your blood monitored regularly. By keeping your clotting times in a safe zone, you will be making sure that a paper clip or a simple bump on the head doesn’t result in a massive life-threatening injury.

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David Khorram, MD is a board certified ophthalmologist, and director of Marianas Eye Institute. Questions and comments are welcome. Call 235-9090 or email eye@vzpacifica.net. Copyright © 2005 David Khorram.