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Interactive Learning : HealthCast Transcripts

Episode 12 : More About Deep Vein Thrombosis

Release Date: February 13, 2007

Dr. David Meyerson: Hi, I'm Dr. David Meyerson, cardiologist at Johns Hopkins and your host for Vascular Disease Foundation's HealthCast. We are privileged to bring you excellent quality and important medical information from peer-reviewed sources as a public service. In each of our HealthCasts, it's our goal that you learn something new or improve your understanding of something you thought you knew so that you might save your life, preserve your functional capacity or do this for someone that you love. Knowing when to seek medical care, when not to ignore warnings and when to possibly push your physician just a bit harder to investigate a problem may save you great pain and function. Very often the outcome is dependent upon a person responds to the warnings they receive and how they communicate them to the medical profession. We want you to understand these red flags and when appropriate, to act on them. This is part two of our discussion on venous thrombo embolic disease, deep vein thrombosis, the blood clots that form in the deep veins in the legs and the potential sequella, the pulmonary embolism, the blood clot that goes to the lungs. These are life threatening medical problems that can be prevented, recognized and treated and with me continuing on in a wonderful series is Dr. Robert B. McLafferty. He is Professor of Surgery in the Division of Vascular Surgery at Southern Illinois University School of Medicine. He is coming to us today from Springfield, Illinois. Dr. McLafferty, thank you so much for continuing on in this very critical public education area.

Dr. Robert McLafferty: Thank you. I'm happy to be here and I enjoyed our previous discussion.

Dr. David Meyerson: Well, I did as well and I think it has benefit -- even if you were a healthcare professional or a lay person, I think we're giving information for both sides of the coin, wouldn't you say?

Dr. Robert McLafferty: Yes I agree. We had stated previously that not only is the public not really aware of the devastation that can occur with deep venous thrombosis or blood clots in the veins, or pulmonary embolism, but also the medical profession and Allied Healthcare professionals also need to get up to speed about how common this disease is.

Dr. David Meyerson: So keeping this high on everybody's radar can actually save lives. I believe that you said in our opening segment, that the frequency of deep vein thrombosis and pulmonary embolism can be as high as the incidence of breast cancer.

Dr. Robert McLafferty: That's correct, so we often hear the quote of one in nine, or one in ten women will develop breast cancer over their lifetime and deep venous thrombosis is as common, in fact, that similar number is that one in twenty people over their lifetime will develop a deep venous thrombosis and the year incidence per hundred thousand population is the same as breast cancer.

Dr. David Meyerson: And again, the risk of this deep vein thrombosis, a blood clot forming in the vein of the legs is that it can break off and travel to the lungs, occlude the flow to the lungs, make somebody either terribly short of breath or frankly, be a life threatening event.

Dr. Robert McLafferty: Essentially these -- you know, when people hear the term blood clot, they often think of different areas depending on the medical news or writings that they've read and this blood clot occurs in the veins, in the deep veins of the leg.

Dr. David Meyerson: Now we talked about earlier, that it travels up to the lungs Why doesn't it go to the brain or other areas? Now I know the answer to this, of course, but I'd like our listeners to be clear about that.

Dr. Robert McLafferty: Well, there's essentially two major sets of blood vessels. The blood clots in the veins are -- if they develop, can travel towards the heart in the same direction or tube that's carrying the blood back to the heart in order for the lungs to oxygenate it again, so if a blood clot is in the legs, in the deep veins of the leg and it breaks off, it travels into the deeper veins of the pelvis, then into the abdomen, and then up to the heart and the chest and then that portion of the heart will pump into the lungs the blood and possibly the blood clot that broke off and when that blood clot becomes lodged in the lungs, it can keep the patient from having other blood go into the lungs to get oxygen.

Dr. David Meyerson: So again, so what you're saying is that if the blood clot is in the legs, and it travels up the inferior vena cava which is the huge vein in the abdomen and then it goes to the heart and the heart then pumps it from the right atrium to the right ventricle, out the pulmonary artery and then to the lungs, that's about as far as it can go because then the blood vessels of the lungs get so tiny, they act as a filter and that's where the blood clot would lodge.

Dr. Robert McLafferty: Yes, I think that's excellently stated and you know, people can die from this condition and sometimes they can be silent as well which is an indicator that they may have another one that can be a major problem. If you look at, for instance, autopsy data in the United States, about fifteen percent of all autopsies have evidence of pulmonary embolism in spite the fact that the patient had died of something else, but nevertheless, this is a very serious problem that can affect people both at home and particularly in the hospital.

Dr. David Meyerson: So when we mentioned the people riding in an airplane for many, many hours on end, and maybe the circulation being compressed by the seat, hitting the back of the leg, any kind of compression of flow of the veins, very tight hosiery for example, that would constrict, maybe even an orthopaedic device after a knee injury or something of that nature, could predispose somebody. We talked about orthopaedic injuries, we talked about certain people with cancers, people that bed rest for a long period of time, so there are -- people really have to have this on their radar and doctors as well. So we talked about teaching the interns and the residents and the medical staffs, the nursing staff, etcetera in the hospital to keep this on their radar. What should patients look for when they're at home or just doing their day to day business? What symptoms might they encounter that should get them to seek attention?

Dr. Robert McLafferty: Well, I think that -- first of all, it's important to tell the public and people that any acute change that is clearly different than the status quo regarding their limbs, their chest or their breathing, is a potential warning sign that a blood clot could be looming. Now there are more common symptoms and typically having one leg swell is a sign, having pain develop in that leg acutely clearly is a sign, developing chest pain, developing shortness of breath. Any of those symptoms should not be ignored and one should report to their doctor immediately.

Dr. David Meyerson: And of course, if you have an episode where somebody passes out or as Dr. McLafferty said, you have terrible shortness of breath that's new in onset and often it comes on like a flash, like an immediate onset, it doesn't have to, but it can and when you go to the hospital emergency room to be evaluated for chest pain, this should be on the doctor's radar. But one of the things you mentioned I think is so critical that one-sided swelling of a leg, when one leg is swollen and the other one is not. Let's explore that a little bit more. Sometimes we see patients, for example, who've had bypass surgery and who've had the superficial vein taken out to be used in the bypass procedure. Sometimes those people can have a little bit more swelling. Sometimes we see people who've had a knee operation or an injury and one leg is a little bit more swollen on a chronic basis. That's not exactly what we're talking about, is that right?

Dr. Robert McLafferty: No, and again with those types of procedures or a baseline of swelling, one can still think about DVT if there's an exacerbation of that entity. So if someone has a little bit of swelling from their vein being taken out for their heart surgery, but then two weeks later develops much more massive swelling in that, that is a clear change and really it's really about knowing your body and using your common sense to say, "Hey this has changed, I should talk to my doctor about this."

Dr. David Meyerson: So if you're four or five days out of an arthoscopic knee procedure, and your starting to feel great, and the knee doesn't hurt you as much as it did, and you think the doctor did a great job. But all of the sudden the lower part of the leg is swelling when it shouldn't. What would you say?

Dr. Robert McLafferty: I would say that that person needs to contact their doctor, either their primary care doctor or their orthopedic surgeon, or go to the emergency room and make sure that it gets checked out immediately. There are numerous cases in orthopedic surgery which is one of the types of surgery that puts patients at very high risk of getting blood clots in their leg. Unfortunately people dropping dead from blood clots going to their lungs, so –

Dr. David Meyerson: Absolutely.

Dr. Robert McLafferty: -- anytime you have orthopedic surgery and there is an acute change in the swelling of the leg. That needs to be addressed immediately.

Dr. David Meyerson: And I would say that in general the orthopedic surgeons in our institution are very, very sensitive. They realize that this is a high risk environment for blood clots to the legs which can then break off and go to the lungs and cause pulmonary embolism and they have all types of devices, they have a mechanical compression device, they give blood thinners and things of that nature, but let's go Dr. McLafferty, a little bit more. So we have a patient who is in their home or at work or not in a hospital setting and so one of the things that we mentioned is that one sided leg swelling, when the other is not is potential warning. What other warnings could you find? Could the leg be hot or painful?

Dr. Robert McLafferty: Yes. The leg can feel maybe not that swollen, but very, very mildly swollen, but feel very hot. The color can change in the leg. It can have kind of a bluish or reddish hue to it. Pain is also another key thing. For instance, feeling like your leg now has developed a charlie horse for no reason at all could be a warning sign that you've developed a blood clot and these things should be addressed, so I think --

Dr. David Meyerson: So let me back up for a second.

Dr. Robert McLafferty: Sure.

Dr. David Meyerson: So we have a higher risk people. People who've had orthopedic injuries, people who have been at bed rest for a while even though they're at home, people wearing an orthopedic appliance, people with certain types of cancers, prostate cancer for example or any other cancer of the pelvis could cause some of this. So what do you tell the patient to do because how it gets treated and how it gets evaluated is going to determine the outcome and we talked about the physical examination by even an excellent doctor, not being able to demonstrate with certainty whether there's a blood clot present or not.

Dr. Robert McLafferty: So, if there's a suspicion of blood clot, there are some tests that can be done to determine, simple tests, that can determine whether it actually is the case and the most commonly used test to determine whether someone has a blood clot in their leg is an ultrasound procedure. That's the procedure where there's some jelly that's put on the leg and a probe and it produces a picture and the technologist can see the veins and use certain maneuvers to see if there's blood clot in the vein and that is the most common test performed to diagnose and is very reliable and accurate test.

Dr. David Meyerson: And this is absolutely harmless, painless and totally safe.

Dr. Robert McLafferty: That's correct. It's a completely safe procedure. There's no needles involved and it's extremely reliable test. It can be done rather quickly, within probably fifteen to thirty minutes to determine whether someone has a blood clot in their leg.

Dr. David Meyerson: And again, if you're a healthcare provider listening or if you're a potential listening, the examination, the physical examination when the doctor's going to evaluate your leg to see whether there's a blood clot in the deep veins of the leg. They miss it half the time, don't they Dr. McLafferty?

Dr. Robert McLafferty: That's right, I --

Dr. David Meyerson: And that's not an exaggeration, that's about the number.

Dr. Robert McLafferty: That's exactly right. They miss it, one because they're not thinking about it or the physical exam itself is not that reliable in terms of the signs that we may look for to determine if there's a blood clot.

Dr. David Meyerson: So I think that's an important point again for the public to understand. Even if you have the best doctor and the best environment, the physical examination can only give you these clues about half the time. The other time, you have to run on instinct and your intuition and your index of suspicion. Something that Dr. McLafferty said more than once, he said, "You have to have a high index of suspicion that these diseases are out there and you just cannot diagnose somebody as a muscle strain when they could have a blood clot to the leg because it could be life threatening."

Dr. Robert McLafferty: That's right.

Dr. David Meyerson: Now let's say, Dr. McLafferty, that the ultrasound examination does show a lower extremity blood clot, what do we do next?

Dr. Robert McLafferty: Well, the large majority of people who have a diagnosis of a blood clot in their leg, will immediately be put on a medication to thin their blood and most commonly it is a medication called Heparin and there are different forms of Heparin both intravenous and from small shots that can be given under the skin. From that, patients can be transitioned to a pill. Typically it's called Warfarin or Coumadin and they have to take that for a prescribed period of time, typically three to six months. In some patients who have had more than one blood clot, they may have to take the medication for life.

Dr. David Meyerson: So let's start then, the right thing then would be to protect somebody immediately and whether that means hospitalizing them with intravenous Heparin going or giving them another form of Heparin which can be self administered called Lovenox would be another way, but again for our medical professionals listening, there are two levels of treatments. One Lovenox level for example would be to prevent and one Heparin level would be to prevent deep vein thrombosis, but anther level would be to actually treat it. So it would be that higher level that you need to actually treat the blood clot of the legs and prevent it from going upstairs. Isn't that right?

Dr. Robert McLafferty: That's right. In fact, when the diagnosis of deep venous thrombosis is made, it is extremely important to give the right dosing of that Heparin or Lovenox immediately to prevent complications such as pulmonary embolism from occurring over the short-term in the next four to twelve hours, so it's incredibly important to get the right amount of medication on board and that's clearly different from dosages that may be given to prevent this occurrence.

Dr. David Meyerson: And just for our listeners sake, why would it be wrong just to treat them with Coumadin alone or Warfarin alone?

Dr. Robert McLafferty: The reason that patients just don't start the pill are a couple fold. First is that Coumadin takes about two to four days to take effect.

Dr. David Meyerson: So you don't get protection, even if you start Coumadin at time zero, there's no protection for possibly three to four days.

Dr. Robert McLafferty: There's no protection. And the second thing is that for a very brief period of time when Coumadin starts to take effect, the body's reaction is to actually make the blood thicker, so a person needs to be on Heparin. I often describe Heparin as the light switch anticoagulant. You can turn it on and turn it off which is really a good thing when someone needs to be anti coagulated or have their blood thinned at high doses.

Dr. David Meyerson: And if somebody is unfortunate enough to have a recurrence of a blood clot in their legs that has gone up to their lungs, and again some of these are not -- a lot of them are not fatal, some of them are, so we want to prevent blood clots traveling. If they have a recurrent events on adequate therapy, you have some mechanical devices that can be used in certain of these patients, is that right?

Dr. Robert McLafferty: Yes. If someone develops a blood clot while they are anti-coagulated or while their blood is thinned, typically one would recommend or the doctor would recommend having a filter placed and that is a small mechanical device, somewhat shaped like an umbrella that allows the blood to flow through it, but it can catch blood clots. It's typically placed in the vena cava which is the large vein in the abdomen that catches all the drainage of the vein in the legs, so this can be placed as an outpatient. It takes about thirty minutes to do.

Dr. David Meyerson: It's a catheter procedure, right?

Dr. Robert McLafferty: It's a catheter procedure that can be done either through the groin or through the neck and rarely sometimes through the arms, but mostly through the groin or neck.

Dr. David Meyerson: So I think what we've tried to do today is to really enlighten both our listeners and hopefully some of our listeners who are also medical professionals about why this has to be so high on health care providers' radar and on patients' radar and at sometimes, sometimes the patient can be the one who educates the doctor and sometimes the patient who can bring it back onto the radar screen, even for a good doctor. Dr. McLafferty, what would be the most important advice that you would like to give to the public today?

Dr. Robert McLafferty: I think that we've said it very nicely in our two discussions thus far and that is to not be afraid to bring this topic up with your doctor. In any instance where you the public may feel you are at risk. Any time you go into the hospital for an overnight stay. Anytime you have surgery. Any other medical condition that you may be in the process of being treated for. It is incredibly imperative to ask your doctor, do I need to have anything done to prevent blood clots from forming in the veins in my legs and that simple question may start a cascade of events that can prevent you from dying from pulmonary embolism.

Dr. David Meyerson: I can't echo that sentiment enough. It is so critical that we be partners with our doctors. Not to take the job away from the doctors, but the sooner it gets on the radar, the sooner you can prevent heartache, no pun intended,

Dr. Robert McLafferty: Yeah.

Dr. David Meyerson: -- and this again, this is preventable disease. It's of the same frequency as breast cancer in our society and women and their loved ones are appropriately fearful of breast cancer and the frequency is so high, this is at the same level and this is preventable disease. There are deaths that are preventable, disability that's preventable and I think we've done a good public service today, Dr. McLafferty. Knowing when to seek medical care, when not to ignore warnings and when possibly to push your physician just a bit harder. To investigate a problem may save you great pain and function and as we have said before, very often the outcome is dependent upon how you respond to the warnings you receive and how you communicate to them to your physicians and to other in the medical profession. We want you to understand these red flags and when appropriate, to act on them. My very special guest today has been Dr. Robert McLafferty. He is Professor of Surgery of the Division of Vascular Surgery at Southern Illinois University School of Medicine in Springfield, Illinois, a national expert on venous thrombo embolic disease, deep vein thrombosis and pulmonary embolis. This is such an important education issue. Please listen, maybe even listen again. If you'd like to look at our website, it's, that's Vascular Disease Special, special information that will save your life and save the life of your loved ones. Again, for the Vascular Disease Foundation, I'm Dr. David Meyerson. Have a great day.


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