August
12
20:06
Diseases of the blood

Hemolysis

Hemolysis

hemolysis photo Hemolysis - a physiological destruction of blood cells, namely cell erythrocyte series, showing the natural process of aging.The direct destruction of blood cells erythrocyte series takes place under the influence of hemolysin, a role which often acts as bacterial toxins.

Causes hemolysis

Depending on the origin of all the variants of hemolytic reactions can be attributed to one of two basic options: a natural or pathological.Natural hemolysis is a continuous chain of chemical processes that result in "physiological update" the composition of red blood cells under normal functioning of the structures of the reticuloendothelial system.

to embodiments of hemolytic reactions that are observed in the laboratory, is a temperature and osmotic hemolysis.In the first type of hemolysis hemolytic chain reaction triggered by the impact of low temperatures on critical components of the blood.When osmotic hemolysis destruction of red blood cells occurs when the blood in a hypotonic envir

onment.For healthy people typical minimum osmotic resistance of erythrocytes, which is within 0.48% NaCl, whereas the complete destruction of the bulk of red blood cells observed at a concentration of NaCl, 0.30%.

In a situation where a patient holds endotoxemia caused by the action of infectious organisms, the conditions for the development of biological hemolysis.Such a hemolytic reaction is observed and incompatible transfusions of whole blood or its components.

Another option hemolytic reaction is a type of mechanical hemolysis, which contributes to the emergence of signs of mechanical impact on the provision of blood (eg, shaking test tubes containing blood).This variant is characterized by hemolytic reactions for patients who produced valvular prosthesis.

There is a whole range of substances with active hemolytic properties, including maximum activity different snake venoms and insect venom.Hemolysis contributes to the development of the impact of a number of chemical groups of chloroform, gasoline and even alcohol.

rare and at the same time the most difficult for the patient etiopathogenetic form of hemolytic reaction is autoimmune hemolysis, the occurrence of which is possible if the body's production of antibodies to the patient's own blood cells, red blood cell number.This pathology is accompanied by severe anemizatsiey the body and release of hemoglobin in the urine in the critically high concentrations.

Symptoms and signs of hemolysis

In a situation where a person does not show signs of pathological hemolysis and destruction of red blood cells occurs in a planned manner with the participation of the structures of the reticuloendothelial system of the intracellular type, no external manifestations of hemolysis people will not feel.

clinical picture of hemolysis is observed only in the case of abnormal flow and includes several periods: hemolytic crisis or acute hemolysis, hemolysis subcompensated phase and remission.

of acute hemolysis, which is characterized by fulminant significantly worsen the health of the patient, there is often incompatible with the transfusion of blood components, severe infection in the body, and toxic effects, such as taking drugs.The danger of this condition is that the hemolytic reaction is so intense that the body lacks compensatory possibilities for products of sufficient red blood cells.Therefore, the clinical symptoms of hemolytic crisis is a manifestation of bilirubin toxicity and severe form of anemia.Specific signs of acute hemolytic crisis occurring is the appearance of intraoperative excessive bleeding nemotiviruemoy wound surface, as well as the allocation of dark urine catheter.

manifestations of bilirubin toxicity is discoloration of the skin in the form of icteric, wearing diffuse intense.In addition, the patient's worries expressed nausea and repeated vomiting, which has no relation with food intake, severe pain in the abdomen, with no clear localization.In severe hemolytic crisis the patient develops lightning convulsions, and various degrees of impaired consciousness.

symptoms are a reflection of an anemic syndrome is a severe weakness and inability to perform normal physical activity, visual pale skin, respiratory disorders as increasing shortness of breath, and an objective examination of the patient often revealed systolic murmur in the projection of the apex of the heart auscultation.Pathognomonic symptom of abnormal intracellular hemolysis is to increase the size of the spleen and liver, and for intravascular hemolysis characteristic change in urine in the form of its darkening.

specific reflections of acute hemolysis is the appearance of specific changes in blood and urine in the form of severe and bilirubinemia hemoglobinemia, thrombocytopenia and decrease fibrinolysis factors, hemoglobinuria and significant increase creatinine and urea.

danger of hemolysis flowing in the acute form, is the possible development of complications of acute cardiovascular failure, DIC, aregeneratornom Stroke and acute renal failure.

In subkompensatornoy hemolysis phase activated processes produce blood cells erythroid marrow, so the severity of clinical symptoms decreased, but saved cutaneous manifestations and hepatosplenomegaly.Anemic syndrome hemolysis at this stage almost not observed, and in a clinical study indicated an increased blood reticulocyte count reflecting the regenerative processes in the blood.

special form of hemolytic reaction is hemolytic disease in children in the neonatal period.Even in utero the fetus hemolytic symptoms arise due to incompatibility between the blood of mother and fetus indicators.The intensity of the reaction of hemolysis is a clear correlation dependence on the magnitude of increase in antibody titer in the blood of pregnant women.

clinical display of hemolysis in newborns can occur in three classic version.The most unfavorable in relation to the recovery of the child is swollen option that significantly increases the risk of stillbirth.In addition to the severe swelling of soft tissues observed excess fluid accumulation in natural cavities (pleura, pericardium, abdomen).

icteric syndrome appears to change color of the skin, amniotic fluid and vernix.There is the appearance of the child's signs of toxic lesions of the central nervous system structures in the form of increased convulsive readiness, rigidity and opisthotonos, oculomotor disorders and symptoms "of the setting sun."The appearance of these symptoms can cause death.

Anemic syndrome in the newborn child, as a rule, is not accompanied by severe clinical manifestations and consists only in changes in laboratory analysis.The duration of an anemic syndrome with a favorable course of hemolysis of the newborn child, as a rule, does not exceed three months.

Types of hemolysis

Under normal functioning of all organs and systems of the human body, the processes of formation of red blood cells and their destruction are in equilibrium.Preferential localization process of destruction of red blood cell blood cells are the structures of the reticuloendothelial system, which is considered the main representatives of the spleen and liver, in which there is a red blood cell fragmentation and the subsequent lysis.With the aging of erythrocyte blood cells lose their flexibility and ability to change their own shape, and therefore, hampered by their passage through the splenic sinuses.The result of this process is the delay of erythrocytes in the spleen and subsequent sequestration.

In fact, not all of the red blood cells circulating in the blood stream, are subjected to the passage of splenic sinuses, and only 10% of their total weight.Due to the fact that fenestrae vascular sinuses are considerably smaller clearance than the standard diameter of the blood cell erythrocytic series, old cells differing stiffness sheath are retained in the sinusoids.Subsequently, erythrocytes undergo metabolic disorder caused by a decreased acidity and a low concentration of glucose in splenic sinuses.The elimination of red blood cells in the sinuses of detainees takes place with the help of macrophage cells that are constantly present in the spleen.Thus, intracellular hemolysis is the direct destruction of the blood erythrocyte number of notches by macrophages of the reticuloendothelial system.

Depending on the preferential localization of the process of destruction of red blood cells, distinguished two main forms: an intracellular and intravascular hemolysis.

extravascular hemolysis destroys up to 90% of red blood cells under normal functioning of the structures of the reticuloendothelial system.Degradation of hemoglobin is a matter of cleavage of the molecules of iron and globin, and the formation of biliverdin under the influence of heme oxygenase.Subsequently starts chain of enzymatic reactions, the end product of which is the production of bilirubin and its delivery into the bloodstream.At this stage activates hepatocyte function which aims at the absorption of the bilirubin from plasma.In situations where a patient has been a significant increase in the concentration of bilirubin in the blood, some of it is not bound to albumin and is filtered by the kidney.

adsorption of bilirubin from the plasma occurs in the liver parenchyma by the activation patterns of the transport system, then there is its conjugation with glucuronic acid.This chemical transformation takes place with the participation of a large number of enzymatic catalysts whose activity depends on the state of hepatocytes.A newborn child has low enzymatic activity of the liver, and therefore, excessive hemolysis in children is caused by the inability of the liver to conjugate bilirubin fast enough.Further transformation

conjugated hemoglobin is in its allocation hepatocytes together with bile, other complexes comprising (phospholipids, cholesterol, bile salts).The lumen of the biliary tract bilirubin chain undergoes changes under the influence of the enzyme dehydrogenase and urobilinogen form which is sucked structures duodenum and subjected to further oxidation in the liver.Part of bilirubin, which is not sucked in the small intestine, enters the small intestine, where it formed a new shape - sterkobilinogena.

Most sterkobilinogena excreted in faeces and the remainder is excreted in the urine as urobilin.Thus, intense hemolysis can be monitored by determining the concentration of sterkolibina.At the same time, for evaluating the intensity of hemolysis should not be considered an increase in the concentration of urobilinogen which increases not only in situations where there is an increased hemolysis, but the morphological and functional lesions weight hepatocytes.

main diagnostic criteria, reflecting the process of increasing the intracellular hemolysis, is to increase the concentration of conjugated bilirubin, as well as a sharp increase in allocation stercobilin and urobilin with the natural body fluids.Development of pathological intracellular hemolysis contributes available to the patient's genetic inferiority of the erythrocyte membrane, violation of hemoglobin production, and excessive amounts of blood cells erythrocyte series, which takes place at physiological jaundice.

At physiological intravascular hemolysis destruction of blood cells erythrocyte series takes place directly in the flow of the circulating blood, and makes this type of hemolytic reaction does not exceed 10% of the total weight of the collapsing of red blood cells.Normal intravascular hemolysis reaction is accompanied by the release of hemoglobin, and the latter with binding globulin plasma.The formed complex structure enters the reticuloendothelial system and subjected to further transformations.

massive intravascular hemolysis is accompanied by a reduced ability gemoglobinsvyazyvayuschey globulin plasma, which is reflected in the allocation of a large quantity of hemoglobin through the structures of the urinary tract.Proceeding to the kidneys, hemoglobin causes changes in its structure in the form of hemosiderin deposits on the surface of the epithelium of the renal tubules, which leads to decrease in tubular reabsorption and release of free hemoglobin in the urine.

Note that there is no clear correlation between the degree and intensity of symptoms hemoglobinemia release of free hemoglobin in the urine.Thus, the reduced ability gemoglobinsvyazyvayuschaya plasma is accompanied by the development of hemoglobinuria even if a slight increase in hemoglobin concentration in the blood.Thus, the main markers of increased intravascular hemolysis flow option is to increase the concentration of free bilirubin in the urine and blood test, as well as accompanying gemosiderinuriya.

development of pathological variants of intravascular hemolysis by a variety of pathological conditions toxic, autoimmune, parasitic origin.

Treatment hemolysis

Because acute hemolytic crisis belongs to the category of emergency conditions, experts developed one algorithm emergency care these patients, including medication and pharmacological component.Relief of symptoms of hemolytic crisis in the acute period should be carried out only in a hospital hematology profile on the intensive care unit beds.

In situations where hemolysis is accompanied by a critical decrease in the level of hemoglobin, the only effective treatment is a red blood cell transfusions in the calculated daily volume of 10 ml per 1 kg of body weight of the patient.In the case of existing signs aregeneratornogo crisis transfusion therapy is recommended to supplement anabolic steroids (Retabolil 25 mg 1 every 2 weeks).

Have the patient signs of acute autoimmune haemolysis is the reason for the use of drugs glucocorticosteroid series.The initial daily dose by 60 mg prednisolone is, however, in some cases the dose may be increased to 150 mg.After the relief of crisis it is expedient to gradually reduce the dose (not more than 5 mg per day) to a level of 30 mg.Further reduction in the dosage provides the drug at a lower 2.5 mg dose every fifth day until the complete abolition.

In a situation where drugs are not glucocorticosteroid therapy has the desired effect in the form of periods of remission, is 7 months or more, the patient is recommended to perform the operational benefits of the removal of the spleen.

refractory forms of autoimmune hemolysis involve the simultaneous use of a number of drugs and the glucocorticosteroid drugs immunosuppressive action (Imuran calculated in a daily dose of 1.5 mg per 1 kg body weight).

deep stages of hemolytic crisis should cropped red blood cell transfusions after Coombs.With a view to the relief of hemodynamic disturbances that often accompany the acute hemolysis, it recommended intravenous Reoglyumana calculated in a dose of 15 ml per 1 kg of body weight.

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