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December 26, 2016 00:02

Hemolytic- uremic syndrome

Hemolytic-uremic syndrome - a varied etiology, but a similar clinical manifestations of symptoms manifested by hemolytic anemia, thrombocytopenia and acute renal failure.

Hemolytic-uremic syndrome was first described as a distinct disease Gasser et 1955, is characterized by a combination of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure in 45-60% of cases ends lethal.

About 70% of hemolytic-uremic syndrome in children described the first year of life, from months of age, the rest - in children over 4-5 years, and single cases in adults.

severity of hemolytic-uremic syndrome determine the degree of anemia and the degree of impairment of renal function;forecast more serious than a lengthy period of anuria.

Causes of hemolytic-uremic syndrome

Hemolytic-uremic syndrome is the principal cause of acute kidney failure in children aged 6 months to 3 years and possible - older children.The development of HUS associated with AII, caused by enterohaemorrhagic Escherichia c

oli 0157: H7, capable of producing Shiga toxin.After 3-5 days of onset of the disease there is a progressive decrease in urine output up to complete anuria.Episode hemolysis and hemoglobinuria in children is usually not diagnosed.

From modern positions, in the pathogenesis of hemolytic uremic syndrome primary importance are viral or microbial toxic damage to the endothelium of the capillaries of the renal glomeruli, the development of DIC and mechanical damage of red blood cells.It is believed that red blood cells are damaged mainly by passing through glomerular capillaries filled with fibrin clots.In turn, the destroyed erythrocytes have a damaging effect on the endothelium of blood vessels, supporting DIC.The clotting process is the absorption of active circulating platelets and clotting factors.

Thrombosis renal glomeruli and arteries bringing accompanied by severe hypoxia of the renal parenchyma, necrosis of the renal tubular epithelium, renal interstitial edema.This leads to a drop in plasma flow and filtration rate in the kidney, a sharp decrease in their concentration ability.

main toxins that contribute to the development of hemolytic-uremic syndrome, according to Shiga-toxin causative agents of dysentery and shigapodobny toxin type 2 (VTEC), normally produced by Escherichia coli serotype 0157 (it may produce and other Enterobacteriaceae).In young children in the capillaries of the renal glomeruli receptors to these toxins are presented to the greatest extent that it contributes to the damage of blood vessels, followed by local ihtrombirovaniem due to activation of the blood clotting.In older children the leading role in the pathogenesis of HUS have circulating immune complexes (CIC) and complement activation, contributing to damage to the renal vessels.

  • What causes hemolytic uremic syndrome?
  • pathogenesis of hemolytic uremic syndrome

Symptoms of hemolytic-uremic syndrome

There are also a particular form of HUS, which is characterized by an innate, genetically caused lack of production of prostacyclin vascular wall endothelial cells.This substance prevents aggregation (agglutination) of platelets near the vessel wall and thus prevents activation of vascular-platelet hemostasis and hypercoagulable development.

Suspicion of hemolytic uremic syndrome in a child with clinical symptoms of DCI, or SARS often occurs when a rapid decrease in urine output against the background of the normal parameters of HEO and the absence of signs of dehydration.The advent of vomiting, fever during this period is indicative of the presence of hydration, swelling of the brain.Complementing the clinical picture of the disease increase in pallor (skin with a yellowish tint), sometimes hemorrhagic rash.

Symptoms of hemolytic-uremic syndrome

diagnosis of hemolytic-uremic syndrome

In the diagnosis of hemolytic-uremic syndrome helps detect anemia (Hb level is usually 9 / L), moderate increase in the concentration of indirect bilirubin (20-30 .mu.mol / l), urea (& gt; 20 mmol / l), creatinine (& gt; 0.2 mmol / l).

diagnosis of hemolytic-uremic syndrome

Treatment of hemolytic-uremic syndrome

In the past, the majority of patients with HUS die - mortality reaches 80-100%.Creating a method of blood purification using the apparatus "artificial kidney" has changed the situation.In the best clinics of the world mortality rate currently varies between 2-10%.The lethal outcome is often due to late diagnosis of the syndrome and the development of irreversible changes in the brain due to its swelling, rarely (in the later period) is associated with nosocomial pneumonia and other infectious complications.

in children with hemolytic uremic syndrome requires from 2 to 9 hemodialysis sessions per course (daily) treatment of acute renal failure.With the help of dialysis maintained close to normal metabolites indicators VEO, prevents hyperhydration, swelling of the brain and lungs.

In addition, the complex treatment of children with hemolytic uremic syndrome includes administration of blood components during their deficit (red cells, or washed red blood cells, albumin, FFP), anticoagulation with heparin therapy, the use of broad-spectrum antibiotics (usually cephalosporins 3th generation), drugs that improve the microcirculation (trental, aminophylline and others.), symptomatic treatment.In general, experience shows that the earlier a child goes to a specialized hospital (prior to the development of the critical state), the greater the likelihood of a successful, complete and rapid cure it.

in predialysis period must be fluid restriction;its prescribed rate of: diuresis the previous day + volume pathological loss (stool and vomiting) + perspiring volume loss (normally from 15 to 25 ml / kg per day) (depending on age).This total volume of fluid administered fractionally, mostly inside.Before the start of dialysis therapy is desirable to limit the consumption of salt, in dialysis and recovery periods diuresis we hardly restrict children receiving salts.

How is hemolytic uremic syndrome?

prognosis of hemolytic-uremic syndrome

When oligoanurncheskogo duration period of more than 4 weeks prognosis for recovery is uncertain.Prognostically unfavorable clinical and laboratory features are persistent neurological symptoms and the lack of positive response to the first 2-3 hemodialysis.In previous years, almost all young children with hemolytic uremic syndrome have died, but with the use of hemodialysis mortality decreased to 20%.