Pulmonary embolism (PE): classification

Depending on the localization of the embolic process, the following clinico-anatomical variants of pulmonary embolism (PE) are distinguished:

• massive - in which embolus is localized in the main trunk or main branches of the pulmonary artery;
• Embolism of lobar or segmental branches of the pulmonary artery;
• Embolism of small branches of the pulmonary artery, which is more often bilateral and, as a rule, does not lead to death of patients.

Depending on the volume of the switched-off arterial channel, a small one (25% off channel volume), submaximal (volume of the switched off channel up to 50%), massive (volume of the switched off pulmonary artery channel more than 50%) and fatal (volume of the switched off channel more than 75%).

The clinical picture of thromboembolism of pulmonary artery PE is determined by the number and caliber of obturated vessels, the rate of embolism, the degree of obstruction of the pulmonary artery. There are 4 main variants of clinical course of pulmonary embolism (PE): acute ("fulminant"), acute, subacute (prolonged), chronic recurrent.

1. The most acute "fulminant" course is observed when the embolom of the main trunk or both main branches of the pulmonary artery is completely blocked by the embolus.

Severe clinical symptoms are associated with profound impairments of vital functions (collapse, acute respiratory failure, respiratory arrest, often ventricular fibrillation), the disease proceeds catastrophically quickly and in a few minutes leads to death. Infarctions of the lungs in these cases, as a rule, are not detected (do not have time to develop).

2. Acute flow (in 30-35% of patients) is observed with rapidly growing obstruction (obturation) of the main branches of the pulmonary artery with involvement of a greater or lesser number of fractional or segmental branches in the thrombotic process. The development of a pulmonary infarction for this variant is not typical, but it occurs.

The acute course of thromboembolism of the pulmonary artery (PE) lasts from several hours to several days (maximum 3-5 days). It is characterized by a sudden onset and a rapid progressive development of the symptoms of respiratory, cardiovascular and cerebral insufficiency.

3. Subacute (protracted) course is observed in 45-50% of patients with embolism of large and medium pulmonary pulmonary arterial branches and is often accompanied by the development of multiple pulmonary infarctions. The disease lasts from one to several weeks. The acute manifestations of the initial period somewhat weaken, the disease takes a slowly progressive nature with the increase in right ventricular and respiratory insufficiency. Against this background, there may be repeated embolic episodes characterized by exacerbation of symptoms or the appearance of signs of a lung infarction. Often there is a fatal outcome - suddenly from repeated embolism of the main trunk or main branches or from progressive cardiopulmonary insufficiency.
4. Chronic recurrent course (observed in 15-25% of patients) with repeated embolism of lobar, segmental, subpleural branches of the pulmonary artery is clinically manifested by recurrent pulmonary infarctions or recurrent pleurisies (more often bilateral) and gradually increasing hypertension of the small circle with development of right ventricular failure. Recurrent PE is more likely to occur on the background of cardiovascular diseases, malignant neoplasms, after operations on the organs of the abdominal cavity.

Classification of PE (Yu. V. Anshelevich, TA Sorokina, 1983)

PE form	Level of defeat	Course of the disease
Heavy	The pulmonary trunk, the main branches of a.pulmonalis	Lightning fast (super-fast)
Medium-heavy	Equity, segmental branches	Acute
Lightweight	Small branches	Recurrent

Severe form of pulmonary artery thromboembolism (PE) is recorded in 16-35% of patients. Most of them in the clinical picture are dominated by 3-5 of the above clinical syndromes with their extreme severity. In more than 90% of cases, acute respiratory failure is combined with shock and cardiac arrhythmias. 42% of patients have cerebral and pain syndromes. In 9% of patients, debut of PE is possible in the form of loss of consciousness, convulsions, shock. Life expectancy from the onset of clinical manifestations can be minutes - tens of minutes.

The medium-heavy form is observed in 45-57% of patients. The clinical picture is less dramatic. The most commonly combined: dyspnea and tachypnea (up to 30-40 per minute), tachycardia (up to 100-130 per minute), moderate arterial hypotension. The syndrome of the acute pulmonary heart is observed in 20-30% of patients. Pain syndrome is noted more often than with severe form, but is moderately expressed. Pain in the chest is combined with pain in the right upper quadrant. Pronounced acrocyanosis. Clinical manifestations last several days.

The mild form with a recurrent course (15-27%). The clinic is little expressed and mosaic, PE is often not recognized, flowing under the mask of "exacerbation" of the underlying disease, "congestive pneumonia." When diagnosing this form, the following clinical signs should be considered: repeated unmotivated syncope, collapse with a feeling of lack of air; transient paroxysmal dyspnea with tachycardia; a sudden feeling of pressure in the chest with shortness of breath; repeated "pneumonia of unclear etiology" (pleuropneumonia); rapidly transient pleurisy; the appearance or intensification of the symptoms of the pulmonary heart, which can not be explained by objective research data; unmotivated fever. The significance of these symptoms increases if they are observed in patients with congestive heart failure, malignant tumors, after operations, fractures of bones, after childbirth, strokes, and signs of phlebothrombosis.

In 1983, VS Saveliev and co-authors. Suggested the classification of pulmonary embolism (PE), which takes into account the localization of the lesion, the degree of violation of lung perfusion (lesion volume), the severity of hemodynamic disorders and the complications of the disease that determine the prognosis of the disease and the method of treatment.

Classification of thromboembolism of pulmonary artery PE (VS Soloviev, 1983)

Localization

1. Level of embolic occlusion:
   • Segmental arteries
   • Fractional and intermediate arteries
   • Major pulmonary arteries and pulmonary trunk
2. Side of defeat:
   • Left
   • Right
   • Two-sided

Degree of pulmonary perfusion disorder

Power	Hagiographic index, points	Perfusion deficiency,%
I (easy)	Up to 16	Up to 29
II (medium)	17-21	30-44
III (severe)	22-26	45-59
IV (extremely severe)	27 and more	60 and more

Complications

• Lung infarction (infarct pneumonia)
• Paradoxical embolism of the great circle of blood circulation
• Chronic pulmonary hypertension