Anemic syndrome
Last reviewed: 23.04.2024
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Anemic syndrome is a pathological condition caused by a decrease in red blood cells and hemoglobin in a circulating blood unit. True anemic syndrome must be distinguished from hemodilution, which is caused by massive transfusion of blood substitutes, accompanied by either an absolute decrease in the number of circulating red blood cells, or a decrease in their hemoglobin content.
How is anemic syndrome manifested?
Acute anemic syndrome, with the exception of some features, is manifested in the same type: euphoria or depression of consciousness; pallor of the skin, tachycardia, initial manifestations of hemorrhagic shock, dizziness, flashing flies before the eyes, reduced vision, tinnitus, shortness of breath, palpitations; auscultation - at the top of the "blowing" systolic murmur. As anemia increases and compensatory reactions decrease, blood pressure progressively decreases and tachycardia increases.
According to the classification of I.A. Kassirsky and G.A. Alekseeva distinguish anemia syndrome of 3 types:
- post-hemorrhagic anemic syndrome - due to blood loss;
- hemic anemia - due to impaired blood formation;
- hemolytic anemic syndrome - due to the destruction of red blood cells.
In addition, there are acute, chronic and acute on the background of chronic anemia.
The volume of blood loss is divided into 3 degrees, which determine its severity: I - up to 15% of BCC - light; II - from 15 to 50% - heavy; III - more than 50% is considered exorbitant, since with such a blood loss, even with its immediate completion, irreversible changes in the system of homeostasis are formed.
The severity of clinical manifestations and the outcome of blood loss is influenced by many factors. The most important are:
- the age of the patient - children due to the imperfection of the compensation mechanisms, and the elderly, because of their exhaustion, suffer even small blood loss very hard;
- speed - the more powerful the bleeding, the faster the compensation mechanisms are depleted, therefore arterial bleeding is classified as the most dangerous;
- the place of blood outpouring - intracranial hematomas, hemopericardium, pulmonary hemorrhages do not give much blood loss, but are the most dangerous due to severe functional impairment;
- a person's condition before bleeding - anemic conditions, avitaminosis, chronic diseases lead to rapid functional decompensation, even with small blood loss.
Blood loss of up to 500 ml is easily and immediately compensated by minor venous spasm, without causing functional disorders (therefore donation is absolutely safe).
Blood loss to a liter (conditionally) causes irritation of the veins receptor volumens, which leads to their persistent and total spasm. Hemodynamic disorders while not developing. Blood loss in 2-3 days is compensated by activating its own hematopoiesis. Therefore, if there are no special reasons, it does not make sense to interfere with the blood stream by transfusion of solutions, to additionally stimulate hematopoiesis.
With blood loss more; liter, except for irritation of veins receptor receptors, alpha receptors of arteries are irritated, which are present in all arteries, with the exception of the central ones, which provide blood flow to vital organs: heart, lungs, brain. The sympathetic nervous system is excited, the adrenal function is stimulated (neurohumoral reaction) and a huge amount of catecholamines is released into the blood by the adrenal cortex: adrenaline is 50-100 times higher than normal, noradrenaline is 5-10 times. As the process grows, it first causes spasm of the capillaries, then small and more and more large ones, except for those with no alpha receptors. Myocardial contractile function is stimulated with the development of tacardia, the spleen and liver are reduced with the release of blood from the depot, arteriovenous shunts in the lungs are revealed. All this in the complex is defined as the development of the syndrome of centralization of blood circulation. This compensatory response allows you to maintain blood pressure and hemoglobin levels for a while. They begin to decline only after 2-3 hours. This time is optimal for stopping bleeding and correcting blood loss.
If this does not occur, hypovolemia and hemorrhagic shock develop, the severity of which is determined by the level of blood pressure, pulse, diuresis and the content of hemoglobin and hematocrit of the blood. This is due to the depletion of the neuro-reflex compensation mechanisms: angiospasm is replaced by vasodilation with a decrease in blood flow in vessels of all levels with erythrocyte stasis, impaired tissue metabolism and the development of metabolic acidosis. The adrenal cortex increases by 3.5 times the production of ketosteroids, which activate the pituitary gland with an increase in the production of aldosterone and an antidiuretic hormone.
As a result, not only the kidney spasm occurs, but also bypass arteriovenous shunts are opened, disabling the juxtoglomerular apparatus with a sharp decrease in diuresis, up to complete anuria. The kidneys are the first to indicate the presence and severity of blood loss, and to restore diuresis, the effectiveness of blood loss compensation is judged. Hormonal changes block the exit of plasma from the bloodstream to the interstitium, which, with impaired microcirculation, further complicates tissue metabolism, aggravates acidosis and multiple organ failure.
Developing adaptation mechanisms in response to blood loss are not inhibited, even with the immediate restoration of the BCC. After replenishing blood loss, blood pressure remains reduced for another 3-6 hours, blood flow in the kidneys - 3-9 hours, in the lungs - 1-2 hours, and microcirculation is restored only on the 4-7th day. Full elimination of all violations occurs only after many days and weeks.
Blood loss of up to 500 ml is considered physiological, and the recovery of circulating blood volume (BCC) occurs independently. You understand that you will not be blood transfused to the donor after exfusion.
With blood loss up to a liter, this issue is approached differentially. If the patient maintains blood pressure, tachycardia does not exceed 100 per minute, diuresis is normal - it is better not to interfere in the bloodstream and the homeostasis system so as not to bring down the compensatory-adaptive response. Only the development of such conditions, anemic syndrome and hemorrhagic shock are indications for intensive therapy.
In such cases, the correction begins at the scene and during transportation. In addition to assessing the general condition, it is necessary to take into account the indicators of ADS and pulse. If the ADS is kept within 100 mm Hg. Art. No need for transfusion of antishock drugs.
With a decrease in blood pressure below-90 mm Hg. Produce a drip transfusion of colloidal blood substitutes. Reduced blood pressure below 70 mm Hg. Art. Is an indication for jet transfusion solutions. Their volume in the course of transportation should not exceed one liter. It is advisable to use autohepatic blood raising the lower limbs, as they contain up to 18% of the BCC.
Upon admission of the patient to the hospital, it is impossible to urgently determine the true volume of blood loss. Therefore, using paraclinical methods for an approximate assessment of the state, since they largely reflect the state of the homeostasis system. Comprehensive assessment is based on the following indicators: BPA, pulse, central venous pressure (CVP), hourly diuresis, hematocrit, hemoglobin content, red blood cells.
Acute anemic syndrome and hemorrhagic shock are within the competence of anaesthesiologists and resuscitators. Starting it without stopping bleeding is meaningless, moreover, the intensity of bleeding may increase.
The main criteria for blood loss replacement are: stable blood pressure at 110/70 mm Hg. V.; pulse at around 90 per minute; CVP at the level of 4-5 cm of water. V.; blood hemoglobin at 110 g / l; diuresis over 601 ml per hour. At the same time diuresis is the most important indicator of BCC recovery. By any means of stimulation: adequate infusion therapy, stimulation with aminophylline and lasix - urination should be restored within 12 hours. Otherwise, necrotization of the renal tubules occurs with the development of irreversible renal failure. Anemic syndrome is accompanied by hypoxia, forming a hemic form, hypoxic syndrome.
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