Prerenal azotemia is an abnormally high level of nitrogen waste products in the blood.
Azotemia – prerenal; Uremia; Renal underperfusion
Causes, incidence, and risk factors
Prerenal azotemia is common, especially in people who are in the hospital.
The kidneys normally filter the blood. When the volume or pressure of blood flow through the kidney drops, filtering of the blood also drops, or may not occur at all. Waste products stay in the blood and little or no urine is formed, even though the kidney itself is working.
Nitrogen waste products, such as creatinine and urea, build up in the body (azotemia). These waste products act as poisons when they build up. They damage tissues and reduce the ability of the organs to function.
Prerenal azotemia is the most common form of kidney failure in hospitalized patients. Any condition that reduces blood flow to the kidney may cause it, including:
Conditions that allow fluid to escape from the bloodstream
Long-term vomiting, diarrhea, or bleeding
Loss of blood volume (such as with dehydration)
Conditions in which the heart cannot pump enough blood or pumps blood at a low volume also increase the risk for prerenal azotemia. These conditions include:
Shock (such as
It also can be caused by conditions that interrupt blood flow to the kidney, such as:
Certain types of surgery
Injury to the kidney
Renal artery embolism
Renal artery occlusion
Confusion Decreased alertness Decreased or no urine production
- Dry mouth
- Pale skin color
Other symptoms may include:
Excessive urination at night
- Pain in the abdomen
Signs and tests
An examination may show:
Collapsed neck veins
Dry mucus membranes
Little or no urine in the bladder
Low blood pressure
Low heart function or
Reduced pulse pressure (difference between systolic blood pressure and diastolic blood pressure)
acute kidney failure
The following tests may be done:
Urine osmolalityand specific gravity
Urine tests to check
sodiumand creatininelevels and to monitor kidney function
The main goal of treatment is to quickly correct the cause before the kidney becomes damaged. People often need to stay in the hospital, and may need treatment in an intensive care unit.
If the person has other symptoms of acute kidney failure, treatment for it should include:
Dialysis, including hemodialysis or dialysis inside the body (peritoneal dialysis)
Prerenal azotemia can be reversed if the cause can be found and corrected within 24 hours. However, if the cause is not fixed quickly, damage may occur to the kidney (
- Acute kidney failure
- Acute tubular necrosis (tissue death)
Calling your health care provider
Go to the emergency room or call the local emergency number (such as 911) if you have symptoms of prerenal azotemia.
Quickly treating any condition that reduces the volume or force of blood flow through the kidneys may help prevent prerenal azotemia.