Thrombus disease screening

The core value of thrombotic disease screening is to detect the risk of invisible blood clots in blood vessels in advance. Currently, the clinically recognized must-screen groups include carriers of family history of thrombosis, long-term sedentary/bedridden people, patients with chronic diseases such as high blood pressure/atrial fibrillation, women during pregnancy and within 6 months after childbirth, and patients after major surgery. For patients within 1 month, the basic screening combination is four items of coagulation + D-dimer + targeted vascular ultrasound. After standardized intervention for high-risk groups identified in early stages, the risk of thrombotic disease can be reduced by 62% (data from the "China Thrombotic Disease Prevention and Treatment Guidelines 2022").

When I was rotating in the vascular surgery department two years ago, I met a 28-year-old Internet operator who worked on projects continuously and sat 14 hours a day for a week. He had never included coagulation-related items in his annual physical examination before. He waited until his left leg was too swollen to put on jeans. It was found that he had deep vein thrombosis in his left lower limb. The emboli had almost blocked the iliac vein. If it fell and swam into the lungs a few days later, it would be a fatal pulmonary embolism.

To be honest, blood clots are no longer an exclusive disease for the elderly. I also met a 22-year-old college student who passed out immediately after playing games for 36 hours. He was sent to be checked for pulmonary embolism. After he was rescued, he was confused and said that he had never heard of young people being checked for blood clots.

As for whether to add blood clot screening to ordinary healthy people, the academic community has not yet reached a consensus. One group advocates adding D-dimer to routine physical examinations for those over 40 years old. After all, this item only costs a few tens of dollars, and it is worthwhile to screen out a few more high-risk ones. It is always more cost-effective than rescuing them when they become ill. However, the other group, most of the specialists in tertiary hospitals are opposed to it. After all, the false positive rate of D-dimer is really high when it comes to pan-screening - if you stayed up late the night before, ran a half-marathon, or even had a cold and inflammation, the result may be high, which will cause anxiety for no reason, and you will have to do a bunch of additional tests to rule it out.

My own advice to patients in outpatient clinics always depends on the situation: if you belong to the high-risk groups mentioned above, don’t hesitate to get checked at least once a year. Elderly people with atrial fibrillation should also do transesophageal ultrasound to see if there is any thrombus in the left atrial appendage; Oh, by the way, if you have just taken a ten-hour long-distance flight, or are in confinement after giving birth, and suddenly develop unilateral leg swelling, pain when walking, or chest tightness and breathlessness for no reason, don't wait for a scheduled physical examination and go directly to the emergency room. At this time, it is not a matter of screening, but a matter of racing against time to save lives.

Many people think that thrombus is a small blood clot in the blood vessel, which is no big deal. In fact, you think of the blood vessel as an old water pipe at home. Thrombus is the scale accumulated on the wall of the water pipe. It usually sticks to the wall of the pipe without feeling it. If it falls off one day, it will become a flowing debris and blockage. If it blocks the blood vessels in the brain, it means cerebral infarction. If it blocks the cardiovascular system, it means myocardial infarction. If it blocks the pulmonary arteries, it means pulmonary embolism. Each of these is a life-threatening emergency. The significance of screening is to find out when it is still stuck to the wall of the tube and either take medicine to dissolve it or adjust your lifestyle to prevent it from growing.

Before, a mother of a second child came for a follow-up check-up. After giving birth, she listened to her family’s advice and lay down for a whole month without getting out of bed. Later, she was diagnosed with chest pain and it was a mild pulmonary embolism. After she was rescued, she told the mother next to her every time she came for check-ups: Don’t just lie down, and you must add a D-dimer for check-ups 42 days after delivery. In fact, there is no standard answer to screening. Don’t listen to what the Internet says that everyone needs to be screened, and don’t think that nothing will happen to you because you are young. If you are not sure, call up a regular number at the vascular surgery department and chat with the doctor for three to five minutes. It is much more effective than reading popular science posts all afternoon.