Acute renal failure, also known as acute kidney failure (AKF), is a condition in which the kidneys become unable to filter waste materials from the blood. When the kidneys lose their filtering abilities, nitrogenous wastes build up, as well as fluid and electrolyte imbalances. Acute renal failure is a condition in which the kidneys, Acute renal damage is another term for failure (AKI). It happens in a matter of hours or days.
Epidemiology
Acute kidney injury is common in hospitalized patients, especially those who are critically ill and require intensive care. It affects 3-7 percent of hospitalized patients and 25-30 percent of patients in intensive care units.
Table of Contents
Causes
Acute renal failure can occur when:
Impaired Blood Flow to the Kidneys:
Diseases and conditions that may slow blood flow to the kidneys and lead to kidney failure include:
- Blood or fluid loss.
- Blood pressure medications.
- Heart attack.
- Heart disease.
- Infection.
- Liver failure.
- Use of Aspirin, Ibuprofen and Naproxen.
- Severe allergic reaction (anaphylaxis).
- Severe burns.
- Severe dehydration.
Damage to the Kidneys:
Certain diseases, conditions, and agents may damage the kidneys and lead to acute renal failure including:
- Blood clots in the veins and arteries in and around the kidneys.
- Cholesterol deposits block blood flow in the kidneys.
- Glomerulonephritis is inflammation of the tiny filters in the kidneys (glomeruli).
- Hemolytic uremic syndrome is a condition that results from the premature destruction of red blood cells.
- Lupus is an immune system disorder causing glomerulonephritis.
- Medications, such as certain chemotherapy drugs, antibiotics, dyes used during imaging tests, and zoledronic acid, are used to treat osteoporosis and high blood calcium levels (hypercalcemia).
- Multiple myeloma is a cancer of the plasma cells.
- Scleroderma is a group of rare diseases affecting the skin and connective tissues.
- Thrombotic thrombocytopenic purpura (TTP), is a rare blood disorder.
- Toxins, such as alcohol, heavy metals, and cocaine.
- Vasculitis is an inflammation of blood vessels.
Urine Blockage in the Kidneys:
Diseases and conditions that block the passage of urine out of the body (urinary obstructions) and can lead to acute renal failure include:
- Bladder cancer,
- Blood clots in the urinary tract,
- Cervical cancer,
- Colon cancer,
- Enlarged prostate,
- Kidney stones,
- Nerve damage involving the nerves that control the bladder,
- Prostate cancer.
Etiologic Mechanisms in Acute Renal Failure
Risk Factors
Acute renal failure almost always occurs in connection with another medical condition or event. Conditions that can increase the risk of acute renal failure include:
- Being hospitalized, especially for a serious condition that requires intensive care,
- Advanced age,
- Blockages in the blood vessels in arms or legs (peripheral artery disease),
- Diabetes,
- High blood pressure,
- Heart failure,
- Kidney diseases,
- Liver diseases.
Pathophysiology
The pressure gradient from the glomerulus to the Bowman space is the driving factor for glomerular filtration. Glomerular pressure is controlled by the combined resistances of renal afferent and efferent arterioles and is principally determined by renal blood flow (RBF). Reductions in RBF, regardless of the origin of AKI, are a common pathologic mechanism for lowering the glomerular filtration rate (GFR). AKI is caused by three primary mechanisms: prerenal, intrinsic, and obstructive.
GFR is reduced in prerenal failure due to poor renal perfusion. The glomerular and tubular functions are both normal.
Intrinsic renal failure includes diseases of the kidney itself, predominantly affecting the glomerulus or tubule, which are associated with the release of renal afferent vasoconstrictors. Ischemic renal injury is the most common cause of intrinsic renal failure. Patients with chronic renal failure may also present with superimposed AKI from prerenal failure and obstruction, as well as intrinsic renal disease.
Obstruction of the urinary tract initially causes an increase in tubular pressure, which decreases the filtration driving force. This pressure gradient soon equalizes, and maintenance of a depressed GFR then depends on renal efferent vasoconstriction.
Symptoms
Signs and symptoms of acute renal failure may include:
- Decreased urine output, although occasionally urine output remains normal,
- Fluid retention, causing swelling in legs, ankles, or feet,
- Drowsiness,
- Shortness of breath,
- Fatigue,
- Confusion,
- Nausea,
- Seizures or coma in severe cases,
- Chest pain or pressure.
Sometimes Acute renal failure causes no signs or symptoms and is detected through lab tests done for another reason.
Complications
Potential complications of acute renal failure include:
Fluid build-up: Acute renal failure may lead to a build-up of fluid in the chest, which can cause shortness of breath.
Chest pain: If the lining that covers the heart becomes inflamed, it may lead to chest pain.
Muscle weakness: When the body’s fluids and electrolytes are out of balance, muscle weakness can result. Elevated levels of potassium in the blood are particularly dangerous.
Permanent kidney damage: Occasionally, Acute renal failure causes permanent loss of kidney function or end-stage renal disease.
Death: Acute renal failure can lead to loss of kidney function and, ultimately death. The risk of death is highest in people who had kidney problems before acute kidney failure.
Tests And Diagnosis
Urine output measurements: The amount of urine excreted in a day may help to determine the cause of kidney failure.
Urine tests: Analyzing a sample of urine, may reveal abnormalities that suggest kidney failure.
Blood tests: A blood sample may reveal rapidly rising levels of urea and creatinine. Imaging tests: Imaging tests such as ultrasound and computerized tomography may be used to help with any abnormalities in kidneys.
Biopsy: In certain situations, a kidney biopsy may recommend removing a small sample of kidney tissue for lab testing.
Treatments and Drugs
Treatment for Acute renal failure involves identifying the illness or injury that originally damaged kidneys.
Balance the number of fluids in blood: If Acute renal failure is caused by a lack of fluids in the blood, may recommend intravenous fluids. In other cases, acute renal failure may cause to have too much fluid, leading to swelling in the arms and legs. In these cases, diuretics may use.
Medications to control blood potassium: If potassium is not properly filtered from the blood, may require calcium, glucose, or sodium polystyrene sulfonate to prevent the accumulation of high levels of potassium in the blood. Too much potassium in the blood can cause dangerous arrhythmias and muscle weakness.
Medications to restore blood calcium levels: In hypocalcemia, calcium infusion is recommended.
Treatment for end-stage kidney disease: If kidneys cannot keep up with waste and fluid clearance on their own and develop complete kidney failure leads to end-stage kidney disease. At that point, dialysis or a kidney transplant is needed.
Dialysis: Dialysis artificially removes waste products and extra fluid from the blood when kidneys can no longer perform normally. In hemodialysis, a machine filters waste and excess fluids from the blood.
In peritoneal dialysis, a thin tube (catheter) inserted into the abdomen fills the abdominal cavity with a dialysis solution that absorbs waste and excess fluids. After a period of time, the dialysis solution drains from the body, carrying the waste with it.
Kidney transplant: A kidney transplant involves surgically placing a healthy kidney from a donor into the body. The transplanted patient may need to take medications for the rest of their life to keep the body from rejecting the new organ.
Prevention
Acute renal failure is often difficult to predict or prevent. But may reduce risk by taking care of kidneys.
Yearly physical examination includes blood tests and urinalysis to monitor kidney and urinary tract health.
Drink enough fluids to keep the kidneys functioning properly.
Avoid taking substances or medications that can poison or damage kidney tissues.
Patients having other diseases or conditions that increase the risk of acute kidney failures, such as diabetes or high blood pressure, must follow recommendations for managing these conditions.
Persons at risk for chronic renal failure may need more frequent testing for kidney function and other problems that occur with declining kidney function.
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