Acute renal failure occurs when the filtering function of the kidneys suddenly decreases as a result of an injury. The kidneys are not able to maintain healthy body functions through the removal of fluids, salts, and waste products.
The kidneys filter the blood in the body and produce urine, thereby clearing the body of many drugs and waste products. They also produce hormones that maintain a normal blood count and can raise blood pressure in response to an injury.
The blood flow to each kidney is supplied by a large artery. Twenty percent of all the blood flow at any time goes to the kidneys. Blood flow is crucial for the health of the kidneys because it allows them to perform their functions of "cleaning" the blood.
Anything that leads to a sudden drop in blood flow to the kidneys or that severely injures the tubes that process blood to make urine can cause acute renal failure. When this happens, the regular functions of the kidneys can be completely stopped temporarily.
At first, there may be no specific signs or symptoms of acute renal failure. The usual things that happen include a decrease in urine flow or a drop in blood pressure. But as the disease progresses, people with decreased urine output retain excess fluid and salts such as potassium chloride.
Common symptoms and signs of acute renal failure include: little to no urine outputfever if there is an infectionbleedingcognitive impairments, which include an altered mental status or comapalpitations, which are unusual sensations of the heart beating rapidly in the chestshortness of breathedema, which means swelling of the extremitiesan abnormal electrocardiogram (ECG)muscle injury and pain
Kidneys that have preexisting disease or damage, especially in a person with diabetes mellitus, are at higher risk for acute renal failure.
The following can lead to acute renal failure: a blockage of urine flow out of the kidneys and into the bladderexposure to certain drugsexposure to toxic substancessignificant loss of blood or sudden drop in blood flow to the kidneys
Kidneys that have preexisting disease or damage are at higher risk for acute renal failure.
Acute renal failure cannot always be prevented. Drugs that can damage the kidneys should be avoided or utilized at the lowest possible effective dose. Persons with preexisting kidney disease need to be very careful to avoid certain medicines that are known to affect kidney function and be given adequate fluid prior to x-ray studies such as heart catheterization. Fluid and blood losses must be corrected. A person with severe muscle injuries should be carefully monitored in the hospital for potential kidney injury.
The diagnosis of acute renal failure begins with a medical history and physical exam. The healthcare professional may order blood tests (kidney function tests) and urine studies. Ultrasound imaging of the kidneys may help pinpoint the cause of the disorder if it is due to obstructed urine outflow.
Most cases of acute renal failure will resolve with supportive therapy. Some causes however, such as ruptured aneurysms, can be fatal in and of themselves. Having had acute renal failure does not mean a person is at risk for long-term kidney damage.
However, a person who has underlying kidney disease, especially a person with diabetes, may not completely recover healthy kidney function. Sometimes, a person can develop progressive kidney damage as a result of acute renal failure and require long-term dialysis therapy later.
Acute renal failure does not put other people at risk.
Diuretic medicines, known as water pills, are sometimes used to help the kidneys get rid of fluid in the body. In other situations, fluids are given to promote increased blood flow to the kidneys. If blood loss or shock has occurred, blood transfusions may be given. Salt imbalances are monitored closely.
Medicines can be given to lower elevated blood levels of certain chemicals. An elevated potassium level is particularly serious and may cause the heart to miss beats or even stop completely.
Dialysis may be used to replace kidney function until the acute renal failure resolves. Dialysis is a procedure where the blood flow from a person is redirected through a special machine. The machine filters the blood and then returns it to the person after wastes, excess salts and fluids are removed..
In most cases, there are few side effects to treatment of acute renal failure itself. . When dialysis is needed, a large intravenous tube, called a catheter, is placed into a vein in the upper arm or chest. This can pose the risk of bleeding or infection.
Treatments given for an underlying disease process, especially cancer, diabetes, or infection, can a variety of longer-term complications specific to the disease involved.
After normal kidney function has returned, the person will be monitored for overall kidney function and balance of chemicals in the blood.
Any new or worsening symptoms should be reported to the healthcare professional. Usually if the cause of acute renal failure is avoided, it does not return.