It has occurred to me for some time that very often, when patients have been asked about the conditions from which their relatives died, answers have been given which have been highly suggestive of one of the complications of this problem. That complication is pulmonary embolism, which I will discuss later in this session.
DEFINITION
Put simply, we are talking about thrombosis of the deep veins of the lower extremity. A thrombus is a fancy word we physicians use for a blood clot. Your lower extremity is your limb, that is your leg, to put it in the most correct of the many ways it is thought of.
In fact, let’s clarify that between your hip and your knee is your thigh, between your knee and your ankle is your leg, and from your ankle downwards is your foot. Ever since I was a boy, everything from the groin downwards was referred to as the foot and, of course, many people still use that today. Now you know.
We all know what a vein is. It is that from which blood comes when you get a cut or have to give blood for a test. We can see them just under our skin, the smaller ones having a blue colour. Veins carry blood to the heart, arteries carry blood from it. The veins we shall be discussing are not the ones you can see or feel, but the ones deep within and between your muscles. Further, not to complicate matters too much, I am going to focus on the veins of the calf, because it appears, in Dominica at least, that deep vein thrombosis (DVT) occurs there more than higher up on the limb. Certainly, people seem to know, and want to know, much more about DVT in the calf.
I must tell you that the venous system in the limb is rather a complicated affair in terms of its anatomy, so in order not to totally lose you, I’ll try to keep it quite simple. I am faced with a dilemma in that although I recognize that DVT can be a serious condition, too many people lose sleep over getting any pain in their calf, just as many of us think that any pain in our chest means we’re getting a heart attack or breast cancer. In fact, many, many cases of calf muscle pain is of muscular origin, and this is not life-threatening. So the best I think I can do is give you some simple facts to educate yourself, make you a little more aware of your body, so that you know when to panic and when not to.
ETIOLOGY
By this we mean cause. What cause(s) DVT in your calf veins? Multiple factors play roles, but the predominant ones follow; broad categories with some specifics.
(1) INJURY TO THE ENDOTHELIUM OF THE VEINS.
What is the endothelium? Of the few layers making up this vessel, tube, called your vein, this is the innermost, the one which you blood makes contact with as it courses through. Among some of the reasons injury occurs are the following.
(a) Indwelling catheters: That is what they put in your veins to give you drips or drugs. Some minor injury in this situation can become bigger and dislodge a small clot to your calf where conditions for a clot formation may be favourable.
(b) Injection of irritating substances: Some drugs, for example, Aminophylline for asthmatics, and Benzylpenicillin for infections, can be quite uncomfortable. Irritation of the endothelium can be a precursor to DVT.
(c) Thromboangiitis obliterans: Does this sound like something we should tackle? Naah. It’s just one of those things to make you sound really smart, so just remember the name for that reason.
(d) Septic phlebitis: Sepis means an overwhelming disease- causing multiplication of bacteria in your blood. Phlebitis implies infection involving the veins. And why not? That’s where the blood is going through. Makes sense, right?
(2) HYPERCOAGULABILITY OF THE BLOOD:
This is when the blood is quick to clot. One can, in fact, say the blood sort of
becomes thick. This may occur in circumstances such as
a) malignant tumours, that is cancers. The number of these that may contribute would require DNO to abandon all its story for today.
b) Blood dyscrasias: This means any of a number of abnormalities involving the various blood cells, one of the more important ones being Polycythemia rubra vera. This is like a too- high haemoglobin value, unlike a too-low one that a good many of us have. In any event, it makes your blood thick and sluggish in its flow. Certainly you can see why it might clot.
c) ORAL CONTRACEPTIVES: I capitalize this because too many of you gals pick them up at the Pharmacy without asking any doctor if they’re O.K. to use, or anything. We always ask you about risk factors for clots, if you’ve had any before, or even if your family members have had them or may be at risk. Be careful.
d) Idiopathic thrombophlebitis: Sound smart again.
(3) STASIS OF BLOOD.
This means blood tending to be stagnant, or which pools.
(a) Post – operative states: many of you who have had surgery, especially below the waist, will remember the little injection, not just antibiotics, that you got every now and then. These are blood thinners, like heparin, to keep your blood from clotting or dissolve clots trying to take hold.
(b) Post-partum states: Especially for those of you women who have to be in hospital after you deliver, be aware.
(c) Stroke. We all know about this
(d) Trauma, especially fractures of the lower extremity.
(e) Congestive Heart Failure: When you heart can’t pump your blood properly, it won’t flow as fast as it should, so it might clot.
(f) Prolonged bed rest for any reason puts you at significant risk.
(g) Varicose thrombophlebitis: Varicose veins. We all know about these. Enough said.
(4) OBESITY
If you think that this puts you at risk for hypertension, diabetes, heart and liver disease, and nothing else, add DVT to the list.
SYMPTOMS AND SIGNS
How might you know you have a DVT of your calf veins? You may have no symptoms (rare) or, over the involved area, variable combinations of pain, tenderness, warmth, bluish discoloration, prominence of superficial veins, or swelling of the leg, ankle, and foot.
You may find that there is soreness or pain on standing or walking, usually relieved by elevating the limb.
What the doctor will find on examination for a DIAGNOSIS includes engorgement of the veins of your foot even after elevation to 45 degrees. He may find 3 dilated veins over your skin (tibia), or, when he asks you to cough or sneeze ( we keep some black pepper in the office for this), you’ll experience pain which disappears with pressure higher up.
If he taps over the surface of the skin (tibia) there may be tenderness of the bone in up to 65% of sufferers.
With your knee flexed and you foot abruptly flexed upward, pain may be felt in the calf. Unfortunately, this test is overused and relied upon almost exclusively but is neither specific nor sensitive. The diagnosis is accurate in less than 40 %.
DIAGNOSTIC TESTS
Depending on where you are, that is let’s say Harward Medical Centre as opposed to Princess Margaret Hospital, a number of different diagnostic tests can be done, all of which have limitations. One may be preferred over the other for a number of technical reasons. I’ll just mention some names to familiarize you.
Some include venography, contrast venography, ultrasound, and Doppler ultrasound with compression, (these latter two are done here), magnetic resonance imaging (MRI), plethysmography, and radionuclide scintigraphy. Despite all these tests, some of them very sophisticated, a high index of suspicisen and a good thorough examination will clinch the diagnosis.
TREATMENT
Hospitalization is a must. The foot of your bed should be elevated six inches. A blood thinner called Heparin or one like it will be started by injection. After a while, a tablet will also be introduced, called warfarin, as the condition improves. Once your condition is stable enough, you will be taken off heparin, and continued on warfarin but be monitored for some time after discharge. Of course, while in hospital, blood will be taken daily to see if you’re getting enough or too much of these drugs. Remember we can’t thin your blood too much, or you will just bleed.
COMPLICATIONS
A clot can dislodge from your calf veins and embolize (travel) to your lungs (Pulmonary Embolism), obstruct flow of blood from your lungs to you heart, and literally stifle you. Ventilation-perfusion scans or angiography can be done to assess if this has occurred. This is a life-threatening complication, as are the other main ones, heart attack and stroke. The mechanism is the same, essentially, and we all know what these complications do, don’t we? Let’s stop here for now. There may be one or two more bits of info we can touch on later, if you’re interested.
See you next week.
Excellent article!!
Dr. Emanuel you always seem to have an article that strikes home or close to home. Keep the information coming, we surely appreciate it!!!
Well thank you Dr for your very informative column. I have always heard about this disease but never actually took the time to read up on it…now I know more.
Please tell… does occasional pain in the knee which comes and goes also a symptom? Thanks once again for all the wonderful info. Blessings.
These weekly explanations are very interesting and important. I pray that the day will come when we can go into a doctor’s office and simply pas through a scanner and take the read out to the doctor, so he can have everything covered. All of this is a lot to look out for. Sometimes I go to the doctor and dont tell him all the things that bother me about my state of health because I fear it will sound psychosomatic.