Definition

Kidney failure occurs when one or both kidneys are not able to perform their usual functions. The kidneys are two bean-shaped organs in the lower back. Their main function is to remove waste from the body and to balance the water and electrolyte content of the blood by filtering the salt and water in the blood. The waste and water excreted by the kidneys combine to form urine.

Kidney failure is divided into acute and chronic.

• Acute kidney failure —sudden loss of kidney function
• Chronic kidney failure —slow, gradual loss of kidney function

If kidney function is reduced to 20% of normal function, serious health problems develop. When kidney function decreases to 10%-15% of normal, dialysis or a transplant is needed to maintain life.

Causes

Kidney diseases cause the tiny filters in the kidneys (called nephrons) to lose their filtering ability. Damage to the nephrons may occur suddenly after an injury or poisoning. However, many kidney diseases take years or even decades to cause damage that is noticeable.

The two most commons causes of kidney failure are:

• Diabetes —Longstanding high blood sugar that results from diabetes damages the nephrons.
• High blood pressure —Longstanding, severe high blood pressure damages the capillaries in the kidneys

Others causes of kidney failure may include:

• Pyelonephritis
• Glomerulonephritis
• Polycystic kidney disease
• Birth defects
• Bilateral renal artery stenosis
• Poisoning
• Severe trauma
• Viral infections: hepatitis B , hepatitis C , HIV/AIDS
• Long-term use of medicines that contain:
  • Aspirin
  • Acetaminophen
  • Ibuprofen
• Abnormal build-up of substances within the kidneys, such as:
  • Amyloidosis
  • Protein build-up
• Toxic reaction to drugs or x-ray dyes
• Systemic diseases, including:
  • Systemic lupus erythematosus (lupus)
  • Polyarteritis
  • Wegener's and Goodpasture's granulomatosis
• Conditions that severely decrease circulating fluid/blood volume, such as:
  • Severe blood loss
  • Burns
  • Pancreatitis
  • Peritonitis
  • Sepsis
  • Heart failure
  • Liver disease
  • Shock (due to any of the above conditions or a sudden and severe drop in blood pressure)
• Conditions that causes obstruction of the flow of urine, such as:
  • Enlarged Prostate
  • Large kidney stones
  • Abdominal tumors blocking the ureters

	Renal Failure
	© 2008 Nucleus Medical Art, Inc.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors for kidney failure include:

• Diabetes
• Genetics: polycystic kidney disease, type 1 diabetes
• Race: African Americans
• High blood pressure
• Lupus or other inflammatory/auto-immune diseases
• Long-term use of painkillers containing aspirin or NSAIDs in high doses
• Liver failure, jaundice
• Respiratory failure
• HIV
• Cancer
• Recent open heart surgery
• Recent surgery on an abdominal aortic aneurysm
• Condition that obstructs urine flow
• Enlargement of the prostate gland

Symptoms

Some kidney diseases begin without any symptoms at all. As kidney failure progresses, some of the following symptoms may develop:

• Fluid retention
• Swollen hands and feet
• Numbness of hands and feet
• Itchy skin
• Fatigue
• Low urine output
• Frequent urination
• Insomnia
• Altered consciousness
• Loss of appetite, malnutrition
• Sores, bad taste in the mouth
• Nausea
• Vomiting
• Muscle cramps and twitches
• Shortness of breath
• Pericarditis
• Swelling throughout the body
• High blood pressure
• Low temperature
• Seizures
• Coma
• Breath smelling like urine (uremic fetor)
• Yellowish-brownish skin tone

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam.

Tests may include:

Blood Tests

Blood tests are done to see if the kidneys are working properly. If they are not working properly, blood levels of potassium, phosphorus, parathyroid hormone, and creatinine, as well as blood urea nitrogen will increase. Serum calcium level will decrease.

Urine Tests

These tests are also done to see if the kidneys are working properly. If they are not working properly, urine may contain elevated amounts of protein. You may be asked to collect urine in a special container over a 24-hour period. In addition to finding out if you are losing protein in your urine, your doctor can determine how your kidneys are functioning by measuring if your kidneys are clearing creatinine at a normal rate. In severe kidney failure, the amount of urine produced may be quite low and can even be completely absent.

Renal imaging

This involves use of ultrasound to take a picture of the kidneys. These pictures will show whether there is a blockage in the flow of urine or a growth on the kidney.

Biopsy

A biopsy involves removing a tiny piece of kidney tissue to see how kidney cells are functioning.

Treatment

Most chronic kidney diseases are not reversible, but the following are treatments that may be recommended to help preserve as much kidney function as possible. These treatments will also be use to try to reverse some of the ill effects of kidney failure.

In the cases of acute renal failure treatment is targeted to the illness or injury causing the problem and try to reverse it.

General Measures

• Fluid restriction
• Daily weight checks
• High-carbohydrate diet
• Low-protein diet

Medications

Use of all medications, both prescribed and over-the-counter, should be carefully reviewed. Medications that rely on the kidney for excretion need to be carefully dosed and monitored, or avoided entirely.

Medications used in acute or chronic kidney failure may include:

• Diuretics, such as furosemide or mannitol—to flush out the kidneys, increase urine flow, and rid the body of excess sodium
• Dopamine, atrial natriuretic peptide (ANP)—to dilate blood vessels in the kidneys, increase urine flow, flush out sodium
• Angiotensin-converting enzyme inhibitors
• Blood pressure medications
• Sodium polystyrene sulfonate or insulin in dextrose—to control high potassium levels
• Calcium acetate—to control high phosphorus levels

Dialysis

Dialysis is a process that takes over for the kidneys and filters potentially toxic waste from the blood. Dialysis may be done temporarily, until kidney function improves, or until a kidney transplant is available.

Kidney Transplant

For some people, receiving a kidney transplant may be the right option. Success of a kidney transplant depends on multiple factors, including whether the underlying cause of the kidney damage is still present, and general state of health of the person receiving the transplant.

Electrolytes, Anemia, and Low Platelet Counts

The following blood measures should be monitored:

• Sodium
• Potassium
• Calcium
• Phosphate
• Red blood cells
• Hematocrit
• Platelets

Injections of erythropoietin, a hormone normally produced by the kidney to stimulate production of red blood cells, may be given to manage the anemia of kidney disease.

Lifestyle Changes

The following are steps to help your kidneys stay healthy longer:

• Have your blood pressure checked regularly and use appropriate medication to control high blood pressure.
• If you are diabetic, control your blood sugar carefully. Ask your doctor or dietitian for help.
• Avoid the chronic use of pain medications.
• If you have chronic kidney disease, you may need to limit your intake of protein. A dietitian can help you adjust your diet.
• Limit cholesterol intake. Cholesterol is present in foods that come from animals, such as meat and dairy products, including eggs.
• Limit sodium intake.
• If you have severe kidney disease, limit your potassium intake (found in fruits, vegetables, nuts, and seeds). Help from a dietitian is crucial if your kidneys are failing.

Prevention

In some cases, you cannot prevent kidney failure. But there are some steps you can take that will lower your risk of kidney failure:

• Maintain normal blood pressure.
• If you are diabetic, control your blood sugar.
• Avoid long-term exposure to toxic substances such as lead and solvents.
• Do not abuse alcohol or over-the-counter pain medication.
• Limit the amount of drugs toxic to the kidney.
• If you have chronic kidney failure, consult your doctor before you become pregnant.

RESOURCES:

American Foundation for Urologic Disease
http://www.afud.org

National Kidney Foundation
http://www.kidney.org

National Kidney and Neurologic Disease Information Clearinghouse
http://kidney.niddk.nih.gov/index.htm

CANADIAN RESOURCES:

Canadian Diabetes Association
http://www.diabetes.ca/

The Kidney Foundation of Canada
http://www.kidney.ab.ca

References:

Glomerular filtration rate, proteinuria, and other markers. Am Fam Physician. 2004;70:1091-1097.

Johnson CA, Levey AS, Coresh J, et al. Clinical practice guidelines for chronic kidney disease in adults: part I. Definition, disease stages, evaluation, treatment, and risk factors. Am Fam Physician. 2004;70:869-876.

Kidney Disease Outcomes Quality Initiative. K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease. Am J Kidney Dis. 2003;42:S1-201.

Kidney Disease Outcomes Quality Initiative. K/DOQI clinical practice guidelines on hypertension and antihypertensive agents in chronic kidney disease. Am J Kidney Dis. 2004;43:S1-S9.

Kidney Disease Outcomes Quality Initiative. Kidney disease outcomes quality initiative (K/DOQI) clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. 2002;39:S1-266.

National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: http://www2.niddk.nih.gov/ .

Snivel CS, Gutierrez C. Chronic kidney disease: prevention and treatment of common complications. Am Fam Physician. 2004; 70:1921-1928.

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