Cardiopulmonary bypass -special medical equipment that is capable of supporting human life processes if the heart or lungs cease to fully or partially perform their functions. The idea of the possibility of realizing the "preservation of any part of the body in the living state" appeared in 1812, but the first primitive device, which consisted of the mechanism of blood injection and oxygenation, appeared only in 1885.
The first open heart surgery where there wasthe heart-lung machine was used in 1930. Since then, several basic methods of using AIC have been used: artificial circulation of the whole organism, regional, where a certain organ or area is supplied with biological fluid, and various variations of the secondary blood circulation.
Общим искусственным кровообращением называется complete replacement of the functions of the heart muscle and gas exchange in the lungs with special mechanical devices and devices. It is widely used in heart surgery.
Blood circulation is called regionalspecific organ or part of the body. This method is used to introduce a significant amount of drugs in the area of purulent infection or a malignant tumor.
Regional artificial circulation hasan option used for short heart surgeries combined with deliberately reducing the body temperature of a person (hypothermia). This method is called coronary carotid perfusion.
Modern cardiopulmonary bypass, the principle of operation of which will be discussed below, must meet the following requirements:
Any cardiopulmonary bypassconsists of a physiological (arterial pump, oxygenator, circulatory circuit) and a mechanical unit. From the patient's body, venous blood enters the oxygenator, where it is enriched with oxygen and cleansing from carbon dioxide, and then with the help of an arterial pump, it returns to the bloodstream.
Before the blood goes back, it passesthrough special filters that trap blood clots, air bubbles, pieces of calcium from the valve system, as well as through a heat exchanger that maintains the required temperature. If the blood in the body is in the cavities, it is sent to the heart-lung machine using a special pump.
AIC has the following structural elements:
Аппарат искусственного кровообращения HL 20 - one of the best examples. The perfusion system in this mechanism meets the highest standards and requirements. It combines safety and reliability, a perfect data collection system, flexibility and the ability to adapt to any manipulation.
Перед использованием обязательно необходимо check the readiness of the mechanism to work. AIC (cardiopulmonary bypass) must have absolute purity and sterility of those surfaces that are in direct contact with blood.
Все структурные элементы, входящие в physiological block, treated with detergents or solutions of alkalis of high concentration with further washing with water. After carry out sterilization. After complete assembly and filling of the apparatus with blood, it is connected to the patient at a certain stage of the operation.
To return blood to the body more often useaccess from the femoral or iliac artery, sometimes through the ascending aorta. The biological fluid enters the apparatus through the drained vena cava. Before blood is supplied to the oxygenator, heparin is administered to the patient (2-3 mg per kilogram of body weight). So that the patient is safe, access to the arterial system is carried out before the catheterization of the venous bed.
Using the cardiopulmonary bypass during operations has certain peculiarities, therefore, anesthesia during this period is different.
When using the apparatus of artificialblood circulation the human body is in unusual conditions. Pathological reactions to perfusion may develop, since retrograde blood flow in the aorta, reduction of pressure in the heart cavities, lack of work of the pulmonary circulation are conditions that are not characteristic of the normal state of the body.
During the intervention manis in a state close to hemorrhagic shock. There is a decrease in blood pressure and general peripheral resistance. Under normal conditions, such a reaction is considered protective, but under the conditions of use of AIC, this interferes with the normal restoration of blood circulation.
The result is the development of hypoxia and metabolic acidosis in the blood. Prevention of complications is based on the improvement of microcirculation, the elimination of the phenomenon of protective redistribution of blood.
The main complications are:
Devices are constantly exposedimprovement to reduce possible complications during the procedure. Modern innovations, technologies and high qualifications of the medical team are the key to successful intervention.
