Hemolytic Uremic Syndrome

Hemolytic uremic syndrome (HUS) is an uncommon, acute kidney disorder. It occurs primarily in children between the ages of 6 months to 5 years. HUS is considered to be the most frequent cause of acute renal failure.  It is characterized by anemia, acute kidney failure and thrombocytopenia.The anemia is a result of the destruction of red blood cells. These damaged red blood cells will eventually clog the filtering system in the kidneys, which may result in the life-threatening kidney failure associated with hemolytic uremic syndrome.

Etiology or Causes

            There are a number of causes for this disorder, but in children it is more frequently associated with the E Coli bacteria. E Coli refers to a group of bacteria normally found in the intestines of healthy humans and animals. Although there are hundreds of strains of E Coli, most of the strains are harmless. E Coli can be found in contaminated meat and produce.  It can also be found in swimming pools or lakes contaminated with feces.  Certain medications and viruses have been known to cause this disorder, as well. There is also a genetic component to a certain type of HUS. Consequently, HUS can be acquired from a parent.

Signs and Symptoms

            The signs and symptoms of this disorder are irritability, fatigue, abdominal pain, vomiting, fever, and pale skin tone. The hemorrhagic manifestations will include bruising, petechiae, jaundice, and bloody diarrhea. Kidney involvement includes blood in the urine and decreased urination. Central nervous system involvement includes seizures, lethargy, stupor and coma.

Diagnostic Test

            A number of tests will be performed to obtain a definitive diagnosis.  However, the anemia, thrombocytopenia and renal failure are sufficient for diagnosis.  A complete blood cell count will reveal a low platelet count, a low red blood cell count and a high serum creatinine level.  A urinalysis is ordered to check for the presence of blood in the urine.  Your doctor may order a stool sample to check for the presence of bacteria.

Treatment and Prevention

            The primary goals of therapy are to diagnose this disease early and to provide contentious, supportive care.  Hemodialysis or peritoneal dialysis is the gold standard for treating the acute renal failure associated with this disease. It is usually implemented if the child has not produced urine for 24 hours or if the child is demonstrating oliguria. Any fluid and electrolyte replacement needed due to fluid loss from diarrhea and vomiting should be done cautiously in light of the fact the kidneys aren’t removing fluid and waste as efficiently as normal. The low red blood cells, hemoglobin and hematocrit levels are treated with red blood cell transfusions given through an IV (intravenous) needle.  Platelet transfusions are given if the child is bruising or bleeding easily because platelets can help your blood clot normally. In extreme cases, plasma exchange may be implemented. Plasma is the liquid component of blood that supports the circulation of blood cells and platelets. With plasma exchange, a machine is used to clear the blood of its own plasma and replace it with fresh donor plasma. This process is known as plasmapheresis.

While specific preventive measure for HUS are not known, it is recommended that everyone should take the following precautions against E. Coli and any other food-borne pathogens:

Good hand washing after using the toilet, after changing a diaper and before eating
Keep food surfaces and utensils clean
Defrost raw meats in the refrigerator or the microwave
Cook ground meat to at least 165 degrees F (71C)
Always wash your fruits and vegetables under running water
Do not drink unpasteurized milk, juice or cider
Keep raw food separated from ready-to-eat foods
Avoid pools of water that are potentially contaminated with feces
Don’t allow anyone to swim in a pool if they have diarrhea

Prognosis

            The recovery rate from this disease is 95%, if treatment is sought early. However, residual kidney impairment ranges from 10% to 50%. This may necessitate the need for supportive care in light of the chronic renal impairment, high blood pressure and central nervous system disorders.  If the kidneys are damaged significantly and the child develops permanent kidney failure, he or she may need to undergo long term dialysis and possibly kidney transplantation.