Prerenal failure is the most common type of acute kidney failures. This article discusses the causes, symptoms, and treatment regarding the same.
Acute Renal Failure (ARF) is the sudden loss of kidney functionality. The causes of ARF are classified into three categories such as prerenal, renal, and postrenal. Prerenal ARF is caused by problems that affect the flow of blood, before it enters the kidneys. Postrenal ARF is caused by problems in passing of urine out of the kidneys. Renal ARF is caused by problems with the kidney itself, resulting in the improper filtration of blood or disrupted production of urine.
Causes
Prerenal ARF is caused mainly by the inadequate blood circulation in the kidneys. As the kidneys do not receive enough blood, they cannot filter the blood properly. Following are the causes of this disorder:
- Atherosclerosis or hardening of the arteries due to increased fatty deposits inside the arteries can significantly reduce the blood flow towards the kidneys.
- Excessive consumption of diuretics, as well as significantly reduced fluid intake can lead to dehydration, which in turn can lead to this disorder.
- People with heart conditions are often advised to take diuretics to prevent accumulation of fluid in the lungs. Such patients are more likely to be affected by dehydration and ARF.
- Severe loss of blood due to a major surgery or accident that leads to sudden drop in the blood pressure levels, may lead to this disorder.
- Chronic liver disease, which affects the production of hormones that help maintain the blood flow and pressure in the kidneys, may also be a contributing factor.
- Prerenal azotemia, a condition where excess amount of nitrogen type compounds in the bloodstream affect the function of the kidneys and lead to the build up of waste, such as creatinine and urea.
- Severe injury or burns, sepsis (infection in the blood), heart failure or heart attack can restrict the flow of blood to the kidneys.
Symptoms
- Dizziness
- Dry mouth
- Low blood pressure (hypotension)
- Increased heart rate
- Dry, loose skin
- Increased thirst
- Weight loss
- Decreased urine output
- Abdominal pain
- Pale skin
- Symptoms of liver disease like itching sensation, nausea, loss of appetite, abdominal swelling, confusion, disorientation, sweet or ammoniacal odor, etc.
- Symptoms of heart diseases like breathing difficulty (Dyspnea), increased fatigue, fluid accumulation and swelling in the extremities (edema), venous engorgement, etc.
- A person affected by azotemia might also exhibit the aforementioned symptoms.
Diagnosis and Treatment
After examining the symptoms, the doctor may ask you to undergo a blood test and urine test. Increased BUN levels in the blood and decreased nitrogen levels in the urine, indicate azotemia. High BUN to creatinine ratio (20:1) and abnormal levels of urine components, indicate prerenal ARF (if postrenal and intrinsic renal causes of ARF are absent). The kidney function is not severely affected in the early stage of this disorder. It is possible to solve the problem with proper and prompt treatment. However, if the problem in the blood or blood circulation is left untreated, then prolonged decrease in the blood flow to the kidneys can lead to kidney diseases or permanently damage the kidney tissues.
The treatment is focused at improving the kidney perfusion (blood circulation). The correct diagnosis or detection of the exact cause of kidney failure, helps determine the treatment. The effect of dehydration can be lowered by administering intravenous fluid. Other causes like infection, liver problem, and heart failure need to be treated according to the types and severity of symptoms. Since the output of urine increases significantly with the administration of intravenous fluids, patients diagnosed with prerenal failure are advised to be admitted in the hospital. The renal function improves fast with the increased output of urine.
Patients with severe symptoms are admitted in the intensive care units, as they have an increased risk of heart failure or liver failure. These patients may suffer from severe infections like viral hepatitis. Patients diagnosed with this disorder need prompt medication in order to prevent health complications.
Disclaimer: This HealthHearty article is for informative purposes only, and should not be used as a replacement for expert medical advice.
