Acute kidney failure
Acute kidney failure is an extremely serious condition in which the kidneys have stopped working and are letting waste products accumulate in the body.
Definition & Facts
Acute kidney failure, which is also known as acute kidney injury or acute renal failure, is the sudden failure of the kidneys to filter waste from an individual's blood. Those wastes accumulate and throw the body's chemical make-up out of balance. Acute kidney failure can be lethal, and it can develop quickly within hours or days. It is most common in older people who are already severely ill.
Conditions often linked to acute renal failure include diabetes, heart failure, high blood pressure, liver disease, kidney disease, and peripheral artery disease which are blockages in the arteries of the arms and/or legs.
Symptoms & Complaints
- Decreased urination in most patients, although some patients continue producing the normal amount of urine
- Fluid retention that causes leg swelling, foot swelling, ankle swelling
- Nausea, vomiting, or reduced appetite
- Severe cases can cause coma or seizures
- Chest pain or pressure in the chest
- Difficulty breathing
- Fatigue or drowsiness
- Anxiety and restlessness
- Flank pain, which is pain in the back right below the rib cage
Acute kidney failure has many causes. It can be caused by a condition that blocks the ureters or tubes that transport urine from the kidneys to the bladder. Such conditions include nerve damage, blood clots in the urinary tract, kidney stones, enlarged prostate and some types of cancer.
Similarly, conditions that impair or prevent blood flow to the kidneys can also cause acute renal failure. These include heart attack, liver failure, some types of heart disease, severe burns, blood loss, severe allergic reaction also called anaphylaxis, severe dehydration and infection.
Some medications can also impede blood flow to the kidneys, and they include naproxen. ibuprofen, aspirin, and blood pressure medications. Additional medications that can damage the kidneys include some antibiotics and chemotherapy drugs, zoledronic acid which is used to treat high blood calcium levels and osteoporosis, and dyes used in imaging tests.
Damage to the kidneys themselves can also cause acute renal failure, and there is a long list of conditions and drugs that can damage the kidneys. Drugs that can damage the kidneys include alcohol and cocaine. Exposure to heavy metals can also cause kidney damage. Conditions that can damage the kidneys include lupus, blood clots in the arteries and veins around the kidneys, certain blood disorders, and kidney infection or inflammation of the kidneys.
Diagnosis & Tests
If a patient shows symptoms of acute kidney failure, their doctor will order a variety of tests to confirm the diagnosis and determine the cause of the kidney failure. Such tests could include:
- Measurements of urine output. The amount of urine the patient produces daily can help the doctor diagnose the cause of the kidney failure.
- Urine tests. In a procedure called urinalysis, the doctor will study the patient's urine for abnormalities linked to kidney failure.
- Blood tests. The doctor may analyze the patient's blood to look for increasing levels of creatinine and urea, which are both used to measure kidney function. He may also order a blood test called a chemistry screen to check the amount of potassium, calcium and sodium in the patient's blood.
- The doctor might use imaging tests like ultrasound or computerized tomography to visually examine the kidneys.
- Biopsy. In a biopsy procedure, the doctor takes a tissue sample from the kidney and sends it to a lab for testing.
In many cases of acute renal failure, the patient is already in the hospital being treated for another condition. If the patient is not in the hospital but has symptoms, they need to consult their doctor immediately. The doctor will ask about the symptoms, any medications the patient uses, and if they have already had any tests.
Treatment & Therapy
Treatment for kidney failure generally involves a stay in the hospital. Since acute kidney failure is usually caused by another disease or disorder, any treatment plan will involve treating the cause of the kidney failure. For example, if a medication or drug is the cause, the patient will have to stop using it. If they are taking the medication to treat another condition, their doctor will have to help them find a substitute they can safely use.
The doctor will also need to treat any complications caused by the kidney failure. For example, kidney failure causes toxins to build up in the blood stream. The patient will need to undergo temporary hemodialysis, more commonly known simply as dialysis, to remove the toxins. In dialysis, a machine pumps the patient's blood through a dialyzer or artificial kidney that filters out the toxins. The machine then returns the purified blood to the patient's body.
The patient will also need treatments to restore balance within their body. If they are dehydrated or lack other fluids, they may need intravenous (IV) fluids. If they have too much fluid that is causing their limbs to swell, the doctor may recommend diuretics to get rid of the excess fluid. Acute renal failure can also cause potassium to accumulate in the blood, and it can cause a patient's calcium levels to drop. The doctor will prescribe the appropriate medications to treat these problems.
Prevention & Prophylaxis
The patient should also work with their doctor to protect their kidneys, especially if they have a history of kidney disease or a condition like diabetes that increases their risks of developing acute renal failure. Such patients should also be careful when using over-the-counter medicines, since some can increase the chances of acute kidney failure.