Prerenal azotemia
Azotemia - prerenal; Uremia; Renal underperfusion; Acute renal failure - prerenal azotemia
Prerenal azotemia is an abnormally high level of nitrogen waste products in the blood.
Causes
Prerenal azotemia is common, especially in people who are in the hospital.
The kidneys filter the blood. They also make urine to remove waste products. When the amount, or pressure, of blood flow through the kidney drops, filtering of the blood also drops. Or it may not occur at all. Waste products stay in the blood. Little or no urine is made, even though the kidney itself is working.
When nitrogen waste products, such as creatinine and urea, build up in the body, the condition is called 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 people. Any condition that reduces blood flow to the kidney may cause it, including:
Kidney failure
Acute kidney failure is the rapid (less than 2 days) loss of your kidneys' ability to remove waste and help balance fluids and electrolytes in your b...
- Burns
- Conditions that allow fluid to escape from the bloodstream
- Long-term vomiting, diarrhea, or bleeding
- Heat exposure
-
Decreased fluid intake (
dehydration
)
Dehydration
Dehydration occurs when your body does not have as much water and fluids as it should. Dehydration can be mild, moderate, or severe, based on how muc...
- Loss of blood volume
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:
-
Heart failure
Heart failure
Heart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...
-
Shock (
septic shock
)
Septic shock
Septic shock is a serious condition that occurs when a body-wide infection leads to dangerously low blood pressure.
It also can be caused by conditions that interrupt blood flow to the kidney, such as:
- Certain types of surgery
- Injury to the kidney
-
Blockage of the artery that supplies blood to the kidney (
renal artery occlusion
)
Renal artery occlusion
Acute arterial occlusion of the kidney is a sudden, severe blockage of the artery that supplies blood to the kidney.
Symptoms
Prerenal azotemia may have no symptoms. Or, symptoms of the causes of prerenal azotemia may be present.
Symptoms of dehydration may be present and include any of the following:
-
Confusion
Confusion
Confusion is the inability to think as clearly or quickly as you normally do. You may feel disoriented and have difficulty paying attention, remembe...
-
Decreased or no urine production
Decreased or no urine production
Decreased urine output means that you produce less urine than normal. Most adults make at least 500 ml of urine in 24 hours (a little over 2 cups)....
- Dry mouth due to thirst
-
Fast pulse
Fast pulse
A bounding pulse is a strong throbbing felt over one of the arteries in the body. It is due to a forceful heartbeat.
- Fatigue
- Pale skin color
- Swelling
Exams and Tests
An examination may show:
- Collapsed neck veins
- Dry mucus membranes
- Little or no urine in the bladder
-
Low blood pressure
Low blood pressure
Low blood pressure occurs when blood pressure is much lower than normal. This means the heart, brain, and other parts of the body do not get enough ...
-
Low heart function or
hypovolemia
Hypovolemia
Hypovolemic shock is an emergency condition in which severe blood or fluid loss makes the heart unable to pump enough blood to the body. This type o...
-
Poor
skin turgor
Skin turgor
Skin turgor is the skin's elasticity. It is the ability of skin to change shape and return to normal.
- Rapid heart rate
- Reduced pulse pressure
-
Signs of
acute kidney failure
Acute kidney failure
Acute kidney failure is the rapid (less than 2 days) loss of your kidneys' ability to remove waste and help balance fluids and electrolytes in your b...
The following tests may be done:
-
Blood creatinine
Blood creatinine
The creatinine blood test measures the level of creatinine in the blood. This test is done to see how well your kidneys are working. Creatinine can ...
-
BUN
BUN
BUN stands for blood urea nitrogen. Urea nitrogen is what forms when protein breaks down. A test can be done to measure the amount of urea nitrogen ...
-
Urine osmolality
and specific gravity
Urine osmolality
Osmolality is a test that measures the concentration of all chemical particles found in the fluid part of blood. Osmolality can also be measured with...
-
Urine tests to check
sodium
and
creatinine
levels and to monitor kidney function
Sodium
The sodium urine test measures the amount of sodium in a certain amount of urine. Sodium can also be measured in a blood sample.
Creatinine
The creatinine urine test measures the amount of creatinine in urine. This test is done to see how well your kidneys are working. Creatinine can als...
Treatment
The main goal of treatment is to quickly correct the cause before the kidney becomes damaged. People often need to stay in the hospital.
Intravenous (IV) fluids, including blood or blood products, may be used to increase blood volume. After blood volume has been restored, medicines may be used to:
Intravenous
Intravenous means "within a vein. " Most often it refers to giving medicines or fluids through a needle or tube inserted into a vein. This allows th...
- Increase blood pressure
- Improve the pumping of the heart
If the person has symptoms of acute kidney failure, treatment will likely include:
-
Dialysis
Dialysis
Dialysis treats end-stage kidney failure. It removes harmful substances from the blood when the kidneys cannot. This article focuses on peritoneal d...
- Diet changes
- Medicines
Outlook (Prognosis)
Prerenal azotemia can be reversed if the cause can be found and corrected within 24 hours. If the cause is not fixed quickly, damage may occur to the kidney ( acute tubular necrosis ).
Acute tubular necrosis
Acute tubular necrosis is a kidney disorder involving damage to the tubule cells of the kidneys, which can lead to acute kidney failure.
Possible Complications
Complications may include:
- Acute kidney failure
- Acute tubular necrosis (tissue death)
When to Contact a Medical Professional
Go to the emergency room or call the local emergency number (such as 911) if you have symptoms of prerenal azotemia.
Prevention
Quickly treating any condition that reduces the volume or force of blood flow through the kidneys may help prevent prerenal azotemia.
References
Goldfarb DA, Poggio ED, Demirjian S. Etiology, pathogenesis, and management of renal failure. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology . 11th ed. Philadelphia, PA: Elsevier; 2016:chap 46.
Wolfson AB. Renal failure. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 97.
-
Kidney anatomy - illustration
The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.
Kidney anatomy
illustration
-
Kidney - blood and urine flow - illustration
This is the typical appearance of the blood vessels (vasculature) and urine flow pattern in the kidney. The blood vessels are shown in red and the urine flow pattern in yellow.
Kidney - blood and urine flow
illustration
-
Kidney anatomy - illustration
The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.
Kidney anatomy
illustration
-
Kidney - blood and urine flow - illustration
This is the typical appearance of the blood vessels (vasculature) and urine flow pattern in the kidney. The blood vessels are shown in red and the urine flow pattern in yellow.
Kidney - blood and urine flow
illustration
Review Date: 10/22/2016
Reviewed By: Walead Latif, MD, Nephrologist and Clinical Associate Professor, Rutgers Medical School, Newark, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.