Diagnosis
Diagnosing pulmonary embolism is difficult, for the following reasons:
- The disorders caused are very similar to those caused by other morbid states.
- Classic diagnostic tests, such as RX-chest or blood tests, are not sufficient to highlight the presence of an occluding blood clot.
- Specific diagnostic tests for pulmonary embolism have a certain margin of risk, therefore they are carried out only if strictly necessary.
Figure: CT scan of a person with pulmonary embolism. The arrows indicate the occluded vessels. From the site: wikipedia.org
During the diagnostic journey, the first step is generally represented by the objective examination, during which the doctor analyzes the signs and symptoms manifested by the patient and collects all the information related to his state of health (clinical history), lifestyle (smoker or non-smoker), work, etc.
Once the physical examination has been completed, more detailed tests and specific examinations for pulmonary embolism are performed.
BLOOD TESTS
The blood tests are aimed at the quantification of D-dimer, a degradation product that forms after the coagulation process (ie the process that forms blood clots).
A high level of D-dimer is generally synonymous with a higher than normal coagulation activity and may therefore indicate that the patient suffers from some thromboembolic disorder.
In contrast, a D-dimer level in the standard excludes that there may be coagulation problems.
The measurement of D-dimer is useful to identify the general characteristics of the pathology in progress (is it a thromboembolic disorder or not?), But it is not very specific: in fact, in the case of high values of D-dimer, it does not clarify what the causes are precise details of this alteration.
CHEST X-RAY
The chest X-ray provides a clear image of the heart and lungs, but is not sufficient in the case of pulmonary embolism.
Nevertheless it is still carried out, in order to make sure that the symptoms accused by the patient are not due to pathological problems of other nature (heart problems, pulmonary fibrosis, etc.).
ecodoppler
Useful in case of suspected deep vein thrombosis, the ecodoppler allows to analyze in real time the anatomical and functional situation of the venous vessels of the legs.
Therefore it clarifies what is the exact dynamics of vascular blood flow (are there occlusions, narrowing or other abnormalities?) And if there are any blood clots inside the vessels.
This is a completely bloodless procedure.
TAC
The CT scan (or computerized axial tomography ) is able to show any abnormalities of the pulmonary blood vessels. Therefore, it is a fairly reliable test.
This is a minimally invasive procedure, as it exposes the patient to a small dose of ionizing radiation.
ANALYSIS OF THE VENTILATION / PERFUSION REPORT: THE PULMONARY DYNOGRAPHY
Pulmonary scintigraphy (or V / Q scan or fan-perfusory scintigraphy ) is divided into two parts or moments.
During the first part, the patient's ventilatory capacity is studied, making him inhale a radioactive gaseous substance, visible with a suitable instrument.
During the second part, instead, lung perfusion is analyzed (that is, how the blood diffuses into the blood vessels that reach the lungs); for this purpose a radioactive substance is injected into the patient's vein, which is also visible with a suitable instrument.
At the end of the second part, the outcomes of each moment are compared: normal ventilation and insufficient perfusion are usually unequivocal signs of a pulmonary embolism
The main drawback of pulmonary scintigraphy is the use of radioactive materials.
PULMONARY ANGIOGRAPHY
Like any type of angiography, pulmonary angiography also allows the visualization of certain vascular districts and the study of their morphology, course and possible alterations.
The examination includes the insertion of a catheter in the venous system and the use of a contrast liquid visible to X-rays; therefore, it is quite invasive.
NUCLEAR MAGNETIC RESONANCE (RMN)
Thanks to the creation of magnetic fields, the MRI provides a detailed image of the internal organs, including blood vessels, without exposing the patient to harmful ionizing radiation.
Because of its costs, it is reserved for special cases, such as pregnant women and people unsuited to scintigraphy.
Treatment
Foreword: the most commonly indicated therapy for pulmonary embolism due to deep vein thrombosis is given below. In the rare cases in which the embolus is not given by a blood clot but by other materials (an air bubble, a lump of fat, a parasite etc.) other types of treatment are necessary.
To treat a pulmonary embolism a pharmacological type therapy is mainly used.
The most commonly used drugs are anticoagulants, such as heparin and warfarin; however, if needed, also thrombolytic drugs could be used.
If the patient is suffering from a massive pulmonary embolism (so it is in an extremely serious condition), and if the aforementioned treatments have been ineffective, it may be necessary to resort to gory and invasive procedures, such as embolectomy and filtering (or filter) cavale.
It is important to remember that care must be given promptly, as the life of a person with pulmonary embolism is put in serious danger.
ANTICOAGULANT THERAPY
The anticoagulant drugs have the power to slow down or interrupt the process of blood clotting, but not to dissolve the blood clots already present. The latter in fact dissolve spontaneously over time.
Usually, patients with pulmonary embolism are given:
- Low molecular weight heparin . Generally, the use of low molecular weight heparin is expected only in the first days of therapy (for a maximum of 5-6 days). Administered intravenously at high doses, it can also be taken at home and not necessarily in hospitals. Today, low molecular weight heparin has taken the place of unfractionated heparin, as the latter requires regular monitoring, then hospitalization.
- Warfarin . Warfarin intake begins at the end of the heparin treatment. Its administration can last several months (at least three) or, if circumstances require it, even a lifetime. Doses vary from person to person; for the right dosage, it may take several attempts and different blood tests to see the response of the blood. Once the adequate amount of warfarin is "found" for a given subject, it must undergo a medical check-up every 30 days.
In order for the medicine to work in the best way, it is good: to adapt to the diet established by the doctor; limit or even not drink alcohol at all; always take the drug at the usual time; contact your doctor before taking any other medication; finally, avoid any pesticides.
| Side effects of low molecular weight heparin | Warfarin side effects |
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THERAPY BASED ON TROMBOLYTICS
Thrombolytic drugs have the ability to dissolve blood clots.
They are administered to a patient with pulmonary embolism when it is necessary to speed up the dissolution of the thrombi present in the blood vessels directed to one of the two lungs.
Since thrombolytics possess dangerous side effects (NB: they predispose to bleeding, even at the intracranial level), their use is usually reserved for cases of massive pulmonary embolism; in the more moderate cases, in fact, it is preferable to resort to anticoagulant therapy.
FILTER (OR FILTERING) CAVAL.
The caval filter, or caval filtering, is a somewhat invasive medical procedure.
Figure: caval filter for inferior vena cava. From the site: wikipedia.org
During its execution, the surgeon inserts in the neck (through the internal jugular vein) or in the upper part of the thigh (through the common femoral vein) a sort of filter that serves to sift the "blood clots" present in the inferior vena cava, in the veins of the legs and in the right side of the heart. The object with which the filter is introduced and guided into the various venous vessels mentioned above is a catheter.
The practice of caval filtering is reserved for patients for whom anticoagulant treatment is not recommended.
PULMONARY EMBOLECTOMY
Pulmonary embolectomy is a surgical operation to remove the emboli or occlude the pulmonary artery and / or its ramifications.
It is a very delicate procedure, not without side effects and still burdened by a high mortality rate. Its execution is reserved for extreme cases or for which pharmacological therapy (eg fatty pulmonary embolism) is considered useless.
Prevention
If for some reason you are at risk of deep vein thrombosis, it is good practice:
- Take anticoagulants . A therapy based on anticoagulants is indicated for hospitalized individuals forced into infirmity, and for those who must observe a period of semi-immobility after surgery on the lower limbs.
They are recommended to those who have undergone surgery or a bone fracture in the lower limbs and to those who travel frequently by plane or car.
As an alternative to compression stockings, there are also inflatable compression bandages.
- Move at regular intervals, even for a few minutes . As in the previous case, this advice is particularly suitable for people who have just undergone surgery on their lower limbs and who travel a lot by plane or car.
Obviously, the newly operated patients are given appropriate exercises, which do not affect the post-operative recovery phase.
Following these recommendations, in addition to preventing deep vein thrombosis, we also protect ourselves against its possible consequences, including pulmonary embolism.
Attention: today, to speed up recovery times and to prevent the formation of blood clots, together with the consequences that may result, doctors strongly advise against excessive post-operative immobility.
OTHER TIPS FOR THOSE WHO TRAVEL MUCH BY AIR OR BY CAR
For those who travel a lot by plane or by car, we recommend:
- Take short walks at regular intervals and for a few minutes. Generally, it is useful to put this advice into practice once an hour.
- When seated, perform special mobility exercises for the legs and hips (for example, lifting the heel by pushing to the ground with the tip of the foot). Furthermore, it is strongly advised against crossing your legs
- Drink water regularly, as dehydration of body tissues contributes to the formation of blood clots. The suggestion to drink regularly is indicated above all for who travels in airplane, to whose inside there is usually a dry air that favors the dehydration.
Prognosis
The prognosis depends on how the pulmonary blood perfusion is compromised (and therefore on the severity of the vessel obstruction), on the speed with which relief is provided (if the situation is very serious) and on any pathologies associated with pulmonary embolism.
