Thromboembolism

Thromboembolic syndrome is a symptom complex that develops during acute thrombus formation in blood and lymphatic vessels or the introduction of an embolus (blood clot, lymph, air) into them, leading to the development of infarctions (strokes, if it concerns the brain or spinal cord) and gangrene.

Thromboembolism affects the vessels of the brain, lungs, intestines, heart, and extremities. This article discusses only arterial thromboembolism.

Cerebral thromboembolism

Arterial thromboembolism of the cerebral vessels is most often observed, mainly in the elderly against the background of atherosclerosis, hypertension, but can also occur in young people against the background of heart defects, vasculitis, obliterating endarteritis, etc.

Thrombosis may occur at any time of the day, but is most often observed during sleep or immediately after sleep. General cerebral symptoms are not pronounced or are absent; consciousness is preserved in most cases, some confusion, increased drowsiness, and disorientation are observed. Focal neurological symptoms develop slowly over several hours or even days. Their manifestations depend on the basin of the affected vessel, the extent of the stroke, and the state of collateral circulation. But in all cases, meningeal syndrome or pontocerebellar syndrome is formed. Brain tumors give the same picture, so patients should be hospitalized in neurosurgical departments. Thrombosis of the sinuses of the dura mater may develop, more often with purulent otitis, mastoiditis, eye diseases, soft tissues of the face, and sepsis. In this case, against the background of a pronounced local purulent process, intoxication syndrome, the clinic of meningeal syndrome develops.

Tactics: patients with cerebral thromboembolism are hospitalized in departments according to the primary pathology for treatment of the underlying cause, but they are treated in the intensive care unit, with the involvement of a neurologist in the treatment in the postoperative period.

Pulmonary embolism

Pulmonary embolism is an acute occlusion of the pulmonary trunk or branches of the pulmonary arterial system by a thrombus formed in the veins of the systemic or pulmonary circulation.

Primary thrombus formation in the pulmonary arteries is extremely rare, in 75-95% of cases the source of thrombi is the inferior vena cava system (mainly the ileocaval segment), in 5-25% of cases thrombi come from the cavities of the heart and in 0.5-2% of cases from the superior vena cava system. Streamlined floating thrombi, loosely connected at one end to the venous wall, pose a particular threat. They break off during straining, coughing, physical exertion, etc. The clinical picture develops suddenly and rapidly. If fulminant death does not occur, which happens with thromboembolism of large branches or bilateral thromboembolism of the pulmonary artery, the clinical picture is variable; depends on the prevalence of embolism and the patient's condition before thromboembolism, but in all cases, in various variations and according to dominant manifestations, the following occur: respiratory failure syndrome, hypoxia, hypertension of the pulmonary circulation, impaired consciousness such as hypoxic coma.

Thromboembolism of small branches of the pulmonary artery proceeds more or less dynamically, when the process develops over several hours or even days. The disease begins with the occurrence of pain behind the sternum like angina, but they do not have a characteristic irradiation and are associated with breathing (increase with inhalation). At the same time, dyspnea develops up to 30-60 breaths per minute, but, unlike pulmonary heart, it does not require taking a vertical or semi-sitting position. Hemoptysis often occurs. Tachypnea leads to hyperventilation of the lungs with the development of hypoxemia (oxygen tension in arterial blood at the level of 70 mm Hg, but at the same time, due to the washing out of carbon dioxide, respiratory alkalosis is formed, only subsequently does acidosis develop. Arterial pressure is persistently reduced; tachycardia, heart rhythm disturbances. With severe hypotension, there may be oliguria, proteinuria, microhematuria. With the development of pulmonary infarction, hemopleurisy often develops.

These patients have the opportunity to conduct instrumental and laboratory studies. A characteristic feature is the presence of hypercoagulation. X-rays reveal expansion and deformation of the lung root, high position of the diaphragm dome and limitation of its mobility, depletion of the pulmonary pattern and increased transparency in the area excluded from the blood flow (symptom of oligemia). As the pulmonary infarction develops, a decrease in pneumatization of the lung area is noted, foci of infiltration appear, intensive darkening of a round, triangular, conical shape with the apex facing the lung root is possible. Radionuclide research using iodine-131 albuminate on scintigrams reveals areas of loss of accumulation of the drug in the capillaries. Angiopulmonography has a greater diagnostic potential, but it is not always possible.

Tactics: emergency care for patients with pulmonary embolism involves hospitalization or transfer to the intensive care unit with the involvement of a thoracic surgeon or cardiac surgeon in the treatment.

Thromboembolism of arteries of the extremities

Thromboembolism occurs when a blood clot or other substrate (a piece of valve, a lost catheter, etc.) moves into a peripheral artery from the proximal parts of the arterial system - the left heart cavity, aorta, iliac artery. The most common cause is heart defects, especially mitral stenosis. Most often, a thrombus forms in the bifurcation zone of the aorta and arteries (femoral and popliteal). The entry of a primary embolus, sometimes quite small, leads to distal and proximal spasm of the vessel and the growth of an ascending and descending thrombus on it, the so-called "tails".

The clinical picture depends on the level of vessel occlusion and the state of blood flow in the limb. Thromboembolism at the level of the aorta is accompanied by bilateral limb damage and occurs as Leriche syndrome. Thromboembolism at the level of the iliac artery is accompanied by unilateral limb damage, with ischemia and lack of pulsation noted throughout the limb, including the common femoral artery on this side. With lower thromboembolism, the level is determined by the absence of pulsation in the limb segments, but... with its presence on the common femoral artery. Depending on the state of the blood supply to the limb, 3 degrees of impaired blood supply and ischemia of the limb are distinguished.

• 1st degree - relative compensation of blood supply - is characterized by a fairly rapid disappearance of pain, restoration of sensitivity and function of the limb, normal skin color, capillary pulsation (determined by capillaroscopy).
• 2nd degree - subcompensation of blood supply - is provided by the maximum tension of collateral blood flow, which maintains the life support of soft tissues at a critical level; accompanied by severe pain syndrome, swelling of the limb, pallor of the skin, a decrease in its temperature, sensitivity, capillary pulsation, but active and passive movements are preserved. Any violation of collateral blood flow at any time can lead to decompensation of blood supply.
• 3rd degree - decompensation of blood supply - the outcome depends on the duration of ischemia. There are 3 phases of the course of absolute ischemia:
  • reversible changes (within 2-3 hours) - manifested by sharp pains in the distal parts of the limb, which quickly disappear, pronounced waxy pallor of the skin, absence of all types of sensitivity and active movements with preserved passive ones, absence of capillary and trunk pulsation;
  • increasing irreversible changes in soft tissues (up to 6 hours from the moment of occlusion) - joint stiffness is added to the clinical picture described above;
  • irreversible changes, i.e. biological death of soft tissues - muscle contracture of the limb is added, brown spots appear on the skin, indicating the onset of gangrene.

Tactics: the ideal option is immediate hospitalization in a vascular surgery center, but due to time constraints this is rarely possible; hospitalization in the intensive care unit for anticoagulant and antiplatelet therapy with a vascular surgeon called in to resolve the issue of thrombectomy.

Mesenteric artery thromboembolism

It is rare, diagnosed before surgery, very rare, since clinically it is accompanied by suddenly developed sharp pains in the abdomen and the presence of peritoneal symptoms, such patients, as a rule, are admitted with diagnoses of peritonitis, perforated gastric ulcer and undergo emergency surgery, thromboembolism is an operational finding.