Outcomes of thrombosis are favorable.

1. Aseptic autolysis (thrombus dissolution).

• It is carried out mainly by the fibrinolytic system:

1) circulating proenzyme, plasminogen and plasminogen activator (secreted by endothelium) bind to fibrin;

2) plasminogen is converted into plasmin (the main fibrinolytic enzyme);

3) dissolution of fibrin using plasmin (fibrinopeptide products of fibrin degradation appear in the blood).

• Proteolytic enzymes of macrophages and leukocytes are also involved in the dissolution of a thrombus.

2 The organization of a blood clot, i.e. replacement of a blood clot by connective tissue that grows up from the intima; the process may be accompanied by sewage and vascularization (restoration of the vessel’s patency).

3. Calcification (in the veins there are stones - phleboliths).

Thrombosis outcomes are adverse.

1. The separation of a blood clot with the development of thromboembolism.

2. Septic melting of a thrombus that occurs when pyogenic bacteria are injected into the thrombotic masses, which can lead to thrombobacterial embolism of the vessels of various organs and tissues (with septicopyemia).

The value of thrombosis is determined by the speed of its development, localization and prevalence. Occlusive blood clots in the arteries lead to the development of heart attacks and gangrene. Vein thrombosis can lead to death from pulmonary thromboembolism.

Embolism - circulation in the blood (or lymph) of particles not found in normal conditions and blockage of vessels by them. The particles themselves are called emboli.

 

Emboli can move along the blood flow (orthograde embolism), against blood flow (retrograde embolism), through the defects in the heart walls of the embolus from the veins of the great circle, bypassing the lungs, can enter the arteries of the large circle (paradoxical embolism). Depending on the nature of the emboli, there are thromboembolism, fat, air, gas, tissue (cell), microbial emboli and embolism by foreign bodies.

1. Thromboembolism occurs when a blood clot or part of it is torn off. This is the most common type of embolism.

Pulmonary embolism.

• The source is usually the blood clots of the lower extremities, the veins of the tissue of the small pelvis that occur during venous stasis, as well as blood clots of the right heart.

• One of the most common causes of sudden death in patients in the postoperative period and in patients with heart failure.

• In the genesis of death in pulmonary thromboembolism, both the closure of the vessel lumen with the development of acute right ventricular insufficiency and the pulmonary-coronary reflex are important: a spasm of the bronchial tree, branches of the pulmonary artery, and coronary arteries of the heart.

• At an autopsy, usually in the general trunk of the pulmonary artery, loosely lying gray-red color of worm-like masses with a dull surface is visible.

• Thromboembolism of the small branches of the pulmonary artery usually develops a hemorrhagic pulmonary infarction.

b. Arterial thromboembolism (arteries of the systemic circulation).

• The source of arterial thromboembolism is more often blood clots that form in the left half of the heart (with endocarditis, malformations, myocardial infarction, etc.) and in the aorta (or large arteries) with atherosclerosis.

• Organs develop heart attacks and gangrene.

Thromboembolic syndrome with heart attacks in many organs often develops.

 

Fat embolism.

Develops when fat enters the bloodstream:

a) in case of traumatic damage to the bone marrow (at the fracture of long tubular bones);

b) at crushing of subcutaneous fatty tissue;

c) in case of erroneous intravenous administration of oil solutions of medicinal or contrast agents.

• Fat droplets that enter the veins occlude the capillaries of the lungs and through the arteriovenous anastomoses enter the circulation, obturating the capillaries of the kidneys, brain and other organs.

• Massive fat embolism leads to acute pulmonary insufficiency: when examining histological lung preparations stained with Sudan III, droplets of orange-red color are detected in the capillaries of the interalveolar septa.

• Fatal outcome can also occur in adipose embolism of brain capillaries, which leads to the appearance of numerous point hemorrhages in the brain tissue.

 

Air embolism.

• It develops when air enters the bloodstream when the veins of the neck are wounded (which is facilitated by negative pressure in them), after childbirth or abortion, if the sclerosing lung is damaged, and if intravenous air is accidentally injected along with the drug.

• air bubbles trapped in the blood cause an embolism of the capillaries of the pulmonary circulation; If air bubbles get into the systemic circulation, brain capillary embolism may develop.

• At the autopsy, an air embolism is recognized by the release of air from the right side of the heart when piercing them, if you pre-fill the cavity of the heart shirt with water. The blood in the cavities of the heart has a foamy appearance.

Gas embolism.

• Characteristic of caisson disease: it develops with rapid decompression (i.e., a rapid transition from elevated atmospheric pressure to normal atmospheric pressure).

• The bubbles of nitrogen released from high pressure in a dissolved state cause blockages in the capillaries of the brain and spinal cord, liver, kidneys and other organs, which is accompanied by the appearance of small foci of ischemia and necrosis (especially often in the brain tissue).

• A characteristic symptom is myalgia.

A special tendency to the development of caisson disease is noted in obese people, since most of the nitrogen is retained by fatty tissue.

Tissue embolism.

It may occur during tissue destruction due to injury or pathological process leading to the entry of pieces of tissue (cells) into the blood. Amniotic fluid embolism in parturients can be accompanied by the development of disseminated intravascular coagulation syndrome and lead to death.

Embolism by malignant tumor cells underlies the metastasis of tumors: in the organs, numerous round tumor nodes often come to light with depressions in the center (necrosis).

Microbial embolism.

Occurs in cases where bacteria circulating in the blood (as well as fungi, animal parasites, protozoa) occlude the lumen of the capillaries. Often, bacterial emboli are formed when a thrombus is purulently melted. Thrombobacterial embolism.

At the site of the blockage of the vessel with bacterial emboli, metastatic abscesses are formed. An example of bacterial embolism is the embolic purulent nephritis that is often found in septicopyemia: the kidney is enlarged; multiple small yellowish foci (foci of purulent inflammation) are visible in the cortex and medulla.

Embolism by foreign bodies. It is observed when catheters, fragments of metal objects (projectiles, bullets, etc.) enter the blood. Foreign bodies also include embolism with lime and cholesterol crystals of atherosclerotic plaques, which propogates in the vessel lumen when they are ulcerated.

Shock

Shock - circulatory collapse, accompanied by hypoperfusion of tissues and a decrease in their oxygenation.

Causes of shock.

1. Reduction of cardiac output (more often with blood loss or severe heart failure).

2. Common peripheral vasodilation (usually with sepsis or severe injury, accompanied by hypotension).

Types of shock.

1. Hypovolemic shock. The basis is an acute decrease in the volume of circulating blood (severe blood loss, fluid loss from burns, indomitable vomiting and diarrhea, etc.).

2. Cardiogenic shock occurs due to a decrease in cardiac output (with extensive myocardial infarction and other conditions leading to acute heart failure).

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