Embolism - Fatty, Air, Pulmonary, Gas And Embolism Of Arteries And Vessels

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-17 02:10

Fat, air, pulmonary and gas embolism

What is embolism?

Embolism is a pathology, exclusively, of the arterial vascular bed, which is based on the overlap of its lumen at a certain level with a partial or complete cessation of blood flow caused by factors not related to the pathology of the affected vessel. Emboli are those substances of the internal environment of the body or the environment that block the vascular lumen. It means that:

1. Embolism is caused by the ingress or migration of emboli into the arteries of the large or pulmonary circulation from other parts of the vascular bed;
2. Emboli can be of a different nature: blood clots, thrombi, detached atherosclerotic plaques, fat cells and oily solutions, air;
3. The sources of emboli can be arterial and venous vessels of any localization, as well as the heart;
4. The diameter of the embolus determines the caliber of the artery that it will block;
5. It is impossible to predict which pool of the arterial vascular bed the embolus will fall into.

The pathogenesis of embolism can take place in three ways:

1. The source of emboli is arterial vessels. In this case, the pool in which the breakdown occurred is affected. In this case, a thrombus or an atherosclerotic plaque, breaking away from its place in a large-diameter vessel, becomes an embolus and migrates to smaller vessels in the basin of its branching;
2. The source of emboli is the venous vessels. Blood clots, air, fat cells can act in their role. Their migration is a little more difficult, since they first enter from the veins into the heart, from where they are thrown in any direction (brain, limbs, intestines, kidneys, etc.);
3. The source of emboli is the heart. These are, as a rule, small blood clots that form against the background of arrhythmias. After they come off the usual place of localization, they migrate to any arterial vessels.

Embolism is always an acute condition that requires urgent action. The ingress of emboli into arterial vessels leads to the cessation of blood flow. This is fraught with ischemia, which can turn into gangrene or organ infarction (within 6-12 hours). This feature distinguishes it from arterial thrombosis, which is a chronic process that compensates for lost blood flow due to collateral (additional) vessels.

Types of embolism

The classification of emboli is based on the type of embolus and its final localization after the cessation of migration. The main types of embolism are shown in the table.

Embolism by localization of the embolus
Thromboembolism (thrombi of arteries, veins and heart act as an embolus)	Pulmonary embolism; Thromboembolism of the carotid arteries and their branches; Thromboembolism of the subclavian arteries and its branches (upper limbs); Thromboembolism of the visceral branches of the aorta (mesenteric and renal arteries); Thromboembolism of the iliac, femoral arteries and their branches (lower extremities); Concomitant multiple lesions of the arterial bed in several basins.
Air and gas embolism (emboli form when air enters a vein or from bubbles of blood gases)
Fat embolism (emboli are fat cells or substances)

It becomes obvious from the table that, regardless of the nature of the embolus, its final localization can be any of the arterial type vessels.

Fat embolism

Fat embolism occurs as a result of the penetration of droplets of fat from melted or destroyed body fat cells into the venous bed. This is possible with massive injuries (trauma to the bones and soft tissues of the extremities, pancreatic necrosis). Another source of fatty embolism can be intravenous fatty solutions that are not intended for this route of administration. Once in the bloodstream, the fat drops are unable to dissolve in the blood. Their dispersal throughout the arterial bed leads to the accumulation of fatty particles in certain places. If there are more of them than the diameter of the vessel, this leads to signs of impaired blood flow. As a rule, fatty embolism is relatively easy, since it affects small vessels.

Air and gas embolism

It is the overlap of the lumen of arterial vessels by air or gas bubbles. This is possible with damage to large veins, especially in the neck. If such a wound is not closed in time, and the vein is compressed, this may result in air being sucked into its lumen, which will enter the heart with the blood flow and spread throughout all arterial basins. As for the possibility of air embolism from air entering the syringe or system during intravenous manipulations, this is practically impossible. For the onset of clinical manifestations of air embolism, its amount should be about 20 ml.

Gas embolism occurs without violating the integrity of the vessels. Sharp changes in atmospheric pressure are to blame for its origin. This is possible in scuba divers and is called decompression sickness. If a diver quickly rises from a great depth, the gas mixture he inhales does not have time to assimilate as quickly as it did at high depths. The result is undissolved air bubbles that block small arterial vessels throughout the body.

Pulmonary embolism

One of the most common and formidable embolisms is pulmonary embolism. In most cases, it is represented by thromboembolism. Regardless of the specific nature of the embolus, the manifestations of the disease in case of damage to vessels of a certain diameter will be identical. On this basis, pulmonary embolism is classified as follows:

1. Embolism of the central trunk of the pulmonary artery;
2. Embolism of large branches of the pulmonary artery;
3. Embolism of small branches of the pulmonary artery.

The first type of disease is considered the most formidable condition. This is due to the possibility of reflex cardiac arrest at the time of the onset of embolism as a result of the pulmonary coronary reflex. This is possible, exclusively, with thromboembolism, when large heart thrombi become emboli and are fixed in the mouth of the pulmonary artery. Air and fat embolism only affects the small branches of the pulmonary artery and does not cause severe manifestations. The exception is cases of massive ejection of small blood clots with a constant new ejection from the heart. The defeat of large branches of the pulmonary artery is often fatal due to the development of acute cardiopulmonary failure or pulmonary infarction.

Embolism of arteries and vessels

The most dangerous of its types are thromboembolic lesions of the arteries of the brain, intestines and kidneys. In all cases of lesions of large great vessels, necrosis of the corresponding organ occurs within a short time (kidney infarction, intestinal gangrene, cerebral stroke). This will lead to either deep disability or death. Embolism of peripheral arteries of extremities proceeds much easier. Usually, they are easy to diagnose, since such conditions occur very acutely and are accompanied by a vivid clinical picture. A timely surgical intervention prevents serious consequences. Otherwise, limb gangrene occurs.

Embolism causes

Each type of embolism has its own causes.

With thromboembolism:

1. Atrial fibrillation and other heart rhythm disturbances;
2. Myocardial infarction;
3. Endocarditis;
4. Left ventricular aneurysm;
5. Hypercoagulation of blood;
6. Diseases of the venous system of the pelvis and extremities (thrombophlebitis, varicose veins, post-thrombophlebitis syndrome);
7. Large operations on the pelvic organs, abdomen and limbs;

For air embolism:

1. Traumatic injuries of large veins;
2. Decompression sickness;
3. Gross violations of the technique of intravenous manipulation;
4. Surgical interventions in gynecology with violation of the technique of their implementation, abortion and difficult childbirth.

With fat embolism:

1. Massive injuries to the limbs;
2. Intravenous administration of prohibited fat-containing drugs;
3. Severe pancreatic necrosis.

Embolism symptoms

Embolic symptoms are well described in the table below:

Symptoms
Pulmonary artery	Sudden pain in the chest or in one half of the chest; Profuse sweating; Drop in blood pressure (90/50 and below); Shortness of breath and rapid breathing (more than 20); Tachycardia (more than 100) and heart rhythm disturbances; Great general weakness; Cough and hemoptysis (join later).
Carotid artery	Headache; Dizziness; Impaired coordination of movements; Movement disorders such as paresis and paralysis; Speech impairment; Clouding of consciousness.
Mesenteric artery	Violent burning pain in the abdomen; Bloody, liquid bowel movements; Bloating; Tachycardia and decreased blood pressure; Lack of rumbling and intestinal peristalsis;
Renal artery	Pain in the projection of the affected kidney; Red urine; Oliguria (the amount of urine is below normal).
Limb arteries	Sudden pain at the site of localization of the embolus, which then spreads to the entire limb; Pallor of the skin of the limb; Coldness of the affected segment and its numbness; Impossibility of active and passive movements; Signs of gangrene (blisters with dark fluid, black spots).

Embolism treatment

Since embolism is an acute illness, its treatment requires urgent measures. The sooner they are provided, the better the prognosis for the patient. Differentiated treatment tactics are shown in the table.

Complex of therapeutic measures
Thromboembolism	Emergency surgery - thromboembolectomy. It is indicated early after the onset of the disease (preferably up to 6 hours). It is performed on all arteries of large and medium calibers, including the arteries of the intestine and the brain. On the pulmonary and renal arteries, thromboembolectomy is practically not performed due to technical difficulties and the severity of the patient's condition (high operational risk). On the limbs, the intervention is performed under local anesthesia and is not difficult. The main criterion for its feasibility is the absence of limb contracture. During the intervention, thromboemboli are removed from the arteries using a special Fogarty probe; Emergency fibrinolysis. The most common type of treatment when thromboembolectomy is not possible. Its focus is the dissolution of thromboemboli. For these purposes, pharmacinase, alteplase, arixtra are used; Anticoagulant therapy - blood thinning. It is best to use ordinary heparin, which is later replaced by analogs (fraxiparine, clexane); Improving the rheological properties of blood and metabolic therapy for affected tissues (rheosorbilact, refortan, trental, actovegin, corvitin, metamax, ascorbic acid); Symptomatic measures. They are aimed at maintaining the main parameters of homeostasis - hemodynamic parameters and respiration. For this, cardiac glycosides (strophanthin, corglikon), glucocorticoid hormones (prednisolone, dexamethasone), diuretics (furosemide), nitrates (nitro-mic, isoket), aminophylline, oxygen instillation, cerebroprotectors (ceraxon, piracetam), are introduced; After the relief of the critical condition, an adequate amount of nutrition (including parenteral) is prescribed, antibiotic prophylaxis of complications of an infectious nature, stress ulcers and bleeding;
Air embolism	Give the lower end of the body an elevated position. At the same time, the head drops slightly; If a central venous catheter is in place, try to aspirate air with a syringe; With a progressive deterioration of the condition, it is recommended to transfer patients to artificial ventilation of the lungs and perform resuscitation measures; Treatment in a pressure chamber and hyperbaric oxygenation; Oxygen instillation; Stabilization of hemodynamic parameters and infusion therapy.
Fat embolism	Stabilization of vital parameters in case of their violation (mechanical ventilation, resuscitation measures); Instillation of oxygen mixture; Drugs that help dissolve fat emboli (Essentiale, Lipostabil, Decholin); Glucocorticoid hormones (dexamethasone, hydrocortisone, prednisolone); Anticoagulants (heparin, clexane); Cardiac glycosides and other symptomatic drugs, depending on the prevailing clinical picture.

Prevention of embolism

Preventive measures are divided into several sections.

Prevention of thromboembolism:

1. taking anticoagulants (aspirin, cardiomagnet, warfarin);
2. Monitoring of blood clotting parameters (APTT, PTI INR), especially in persons at risk for thromboembolic complications;
3. Timely and adequate treatment of cardiac arrhythmias;
4. Elimination of venous pathology of the lower extremities;
5. Installation of kava filters for people at risk;
6. Elastic compression of the legs and prophylactic doses of anticoagulants in at-risk individuals who are to undergo surgery;
7. Dosed physical and mental stress.

Prevention of air embolism:

1. Compliance with the rules of smooth ascent from high depths by divers;
2. Correct and fast treatment of wounds with damage to venous vessels;
3. Correct placement of women on the operating table during gynecological operations, careful and quick ligation of damaged veins;
4. Strict adherence to the technique of performing intravenous injections;

Prevention of fat embolism:

1. Prevention of injuries;
2. Fast and stable immobilization of the injured limb;
3. Early surgical interventions or other methods of reduction, leading to the stabilization of bone fragments;
4. Compliance with the rules of intravenous administration of drugs.

The author of the article: Volkov Dmitry Sergeevich | c. m. n. surgeon, phlebologist

Education: Moscow State University of Medicine and Dentistry (1996). In 2003 he received a diploma from the Educational and Scientific Medical Center of the Presidential Administration of the Russian Federation.