Pulmonary Embolus

small logo
What is Pulmonary Embolus?

The word pulmonary stands for lungs and embolus means blood clot that travels, so Pulmonary Embolus (PE, for short) is a medical condition where clots "swim" in the blood stream towards the lungs, are "filtered" and caught in the pulmonary artery (the main artery of the lungs), causing obstruction of blood flow into the lungs, resulting in hypoxia (diminished oxygen blood level). Pulmonary embolus is a serious condition which could be fatal, if not detected and treated promptly.

What are the signs and symptoms of PE?

The clinical symptoms are usually nonspecific, depending on the severity of the pulmonary artery blockage. There could be chest pains, cough, shortness of breath, tachypnea (fast and shallow breathing), hemoptysis (spitting of blood) lightheadedness, fainting, occasionally with lung wheezing, anxiety and restlessness, and even a sense of impeding doom. Frequently, these patients are asymptomatic (with no symptoms at all). Many times, only a high index of suspicion on the part of the physician would allow for an accurate diagnosis. Lung scan, and in chosen cases, pulmonary arteriogram, are performed to confirm the diagnosis.

Where do traveling blood clots come from?

Blood clots usually form in the legs (among patients with phlebitis, or inflammation of the inner walls of the veins) or in the veins within the pelvis, from similar inflammatory condition. All these veins are interconnected and eventually flow into a common channel known as the inferior vena cava. The "used" blood from the head and neck and upper shoulder areas flow into the superior vena cava. Both of these caval veins drain into the right chambers of the heart and from there, the "used" blood goes to the lungs where it will oxygenated, and the entire cycle goes on, repeatedly, at least 60-70 times a minute. Blood clots could also from within the chambers of the heart and major arteries and veins in the body.

What causes blood to clot?

There are many factors that cause blood clots in the body: idiopathic (cause unknown; some people are more prone to clot formation), smoking, stress, high blood pressure, high cholesterol level, dehydration (where blood thickens), varicose veins (where blood flow is slowed down), lack of physical exercise, a bed-ridden state (after a major surgery), pregnancy, where the enlarged uterus presses upon the pelvic veins, slowing down the circulation and resulting in clot formation.

Why keeps blood in liquid form in our body?

Blood stays liquid in our circulation because our body has a built-in "anti-clot enzyme system." As long as the person is healthy and has no disease or condition that will adversely affect the delicate "balance" in the individual's homeostasis, this inherent protective enzyme system will keep the blood in liquid form and in constant motion. If any one or a combination of the factors listed in the preceding paragraph prevails to thwart the "balance," blood clots will form.

What does an embolus do?

As we have stated earlier, an embolus is a blood clot (or a piece of dislodged cholesterol plaque from the wall of an artery) that travels, from the area where it has formed (in the vein or artery, or even in the heart), to the flow destination of the circulation. Example, blood clots from the leg veins to the lungs, resulting in pulmonary embolism); from the abdominal aorta to the legs (causing gangrene); from the thoracic (chest) aorta to the brain, or, from the heart to the brain, causing a stroke.

How does one prevent blood clots?

The avoidance of the various factors listed earlier is the best way to ward off blood clots. Smoking thickens the blood, and makes it prone to clot formation. And so with high cholesterol blood level and untreated or inadequately treated high blood pressure. An active lifestyle, including daily physical exercises, is a helpful antidote to clot formation. Those prone to leg swelling after a day on their feet need to elevate their legs (feet higher than the knees, and knees higher than the groin) to help the blood stagnant in the legs flow back more efficiently back to the lungs and heart. If needed, support stockings may be used when the individuals are up on their feet. Keeping proper hydration by drinking 6-8 glasses of non-alcoholic fluids (water, milk, juices, etc) helps prevent blood from thickening and clotting. Low fat (red meat-free fish, vegetables and fruit) diet to manage the cholesterol level will also reduces the risk of blood clots. If necessary, the attending physician may prescribe a blood thinner, like aspirin or coumadin, for those with recurrent thrombophlebitis (inflammation of the varicose veins with blood clot formation).

Are there drugs that dissolve clots?

Yes, there are, but they are usually not effective enough to dissolve big clots, especially clots that are a day old or older. These drugs (enzymes) are initially used, with the goal and hope of dissolving clots that are still "young enough" to dissolve, if only to tide the patient over a critical period and to stabilize the vital signs. If the patient's condition responds favorably to the use of these enzymes, no surgery is performed. A regimen of blood thinner therapy and preventive measures are instituted.

How does aspirin reduce clot formation?

Aspirin (acetyl salicylic acid), the wonder drug of many preventive and therapeutic uses, is an anti-platelet agent, a blood thinner. As such, it prevents platelet aggregation (red blood cells clumping together and adhering to each other to form clots). This blood thinner is also known to boost the immune system, and reduce the risk off colon cancer, besides its ability to lessen the risk of heart attack when taken as a mini-dose (81 mg) a day, under physician supervision. While it is a common household drug, aspirin is not devoid of potential adverse side-effects, such as stomach bleeding, which could be life-threatening. The prudent way is to consult your physician before taking any medications, even one as "simple" as aspirin.

What is the treatment of PE?

Prevention is the key in dealing with this potentially deadly condition. When suspected, the condition is first confirmed by a complete history and physical examination, and lung scan. When the vital signs are not stable (low blood pressure, intractable shortness of breath, low oxygen blood level), pulmonary arteriogram may be done. If the blood clots in the pulmonary arteries are too large and not dissolving with intravenous thrombolytic enzymes (clot-dissolving drugs) and intravenous heparin (blood thinner), and if the vitals signs remain unstable, emergency surgery to remove these offending clots is performed, with the aid of a heart-lung machine.

©2003Raoul R. Diez, M.A.O.D.