Oliguria Information

When a person's urine output is considerably reduced and less than 500 milliliters are excreted within a period of 24 hours, a person is said to have Oliguria.

The kidney is a part of the body responsible for producing urine. It works hand in had with the body's blood flow, closely matching its pressure. A substantial decrease in urine can signal a serious medical problem that may be life threatening in the extreme.

Oliguria is categorized based on the factors that cause it. Prerenal Oliguria occurs when the kidney undergoes hypoperfusion as a result of decreased intake of fluids, dehydration, diarrhea, excessive bleeding, or sepsis. Renal Oliguria occurs due to a damaged kidney caused by medication, rhabdomyolysis, or hypoperfusion. Postremal Oliguria is caused when the urine flow is obstructed by conditions such as an enlarged prostate, a neoplastic tumor, a hematoma, or a collection of solidified fluid.

Oliguria is determined based on the amount of urine output excreted by a person. In infants, it is measured at less than 1 milliliter per kilogram an hour; in children, urine output is less than 0.5 milliliter per kilogram an hour, and in adults, at less than 400 milliliters per day.

If a person notices a significant and consistent drop in the amount of urine output, the condition is a cause for concern and may signal the presence of Oliguria. A person who has developed this condition may also experience diarrhea, a high fever, vomiting, and being unable to get enough fluid intake to replace the fluid lost as a result. Other symptoms include lightheadedness, palpitations, and dizziness.

While a decrease in urine production points toward renal failure, dehydration, urinary obstruction or retention, Oliguria may be caused by many different conditions:

When a person experiences abrupt Oliguria, or a gradual onset of decreased urine output over a period of two weeks, Acute Tubular Necrosis may be the culprit. Apart from Oliguria, symptoms of this condition include arrhythmias, muscle weakness, anorexia, lethargy, pruritus, confusion, seizures, uremia, dyspnea, distension of the jugular vein, and heart failure.

A deposit of calculi in the ureters, urethra and kidneys may also cause Oliguria. A patient with calculi may experience severe pain in the flanks, pubic region and external genitalia, as well as nausea, vomiting, a distended abdomen, an increase in bowel sounds, as well as fever and chills.

Oliguria may also be caused by Cholera, a bacterial infection characterized by dehydration due to fluid and electrolyte loss, extreme thirst, muscle cramps, weakness, hypotension, vomiting, severe watery diarrhea, and tachychardia. Without treatment, a person afflicted with Cholera can die within hours.

Acute Glomerulonephritis is another condition that may trigger the onset of Oliguria. A person with Acute Glomerulonephritis exhibits symptoms of fatigue, mild fever, edema, high blood pressure, headaches, nausea and vomiting, pulmonary congestion, and abdominal pain.

When heart failure occurs, Oliguria may accompany it. This is a result of decreased cardiac output and an increase in renal perfusion. In these cases, a patient may experience fatigue or weakness, dyspnea, distension of the jugular vein, peripheral edema, tachychardia, and a dry cough.

Hypovolemia is another cause of Oliguria. It is characterized by a marked decrease of fluid circulation in the body. A person diagnosed with Hypovolemia will experience fatigue and lethargy, hypotension, severe weakness of the muscles, nausea, anorexia, extreme thirst, dizziness, dryness of the mucous membranes, and sunken eyeballs.

Other causes of Oliguria include Acute Pyelonephritis; Chronic Renal Failure, particularly in its final stages; Bilateral Renal Vein Occlusion; Preeclampsia during pregnancy, and Urethral stricture.

Patients who have Oliguria may develop the condition after having undergone a surgical procedure. In this case, Oliguria may be the body's response to several factors which include blood or fluid loss, dehydration stemming from fever, vomiting, diarrhea, and inadequate intake of fluid, severe infection that results in toxic shock, urinary obstruction caused by an enlarged prostate, and as a reaction to certain post-operative medications like anticholinergics, diuretics, and methotrexate.

To diagnose Oliguria, the doctor will take down the patient's complete medical history and subject the patient to a thorough physical examination. The doctor will likewise ask about the patient's urine output, such as the time pattern of urination, when the decrease in output began, and the severity of the condition.

The doctor will also inquire about the volume of fluid the patient consumes each day, the volume of urine output, and the color of the urine excreted. The doctor will determine if there are any aggravating factors that accompany the symptoms, such as fever, nausea, vomiting, diarrhea, and increased thirst, as well as any other related symptoms, previous kidney or bladder problems, recent injuries, regular medications, and allergies that a patient has to determine the presence of an underlying disorder.

The patient may be subjected to several diagnostic tests to check for any underlying ailments that may be causing the Oliguria. The doctor may order a urinalysis to check for the presence of an infection or inflammation in the kidneys or bladder. A urine culture also may be taken to check for the presence of any bacteria. An x-ray test known as an intravenous pyelogram involves a dye injected into a vein in the arm to identify tumors and kidney stones, and an ultrasound will be used to check for the presence of a kidney mass or cyst.

Other diagnostic procedures include an abdominal and pelvic CT scan to look at three-dimensional images of the kidneys, pelvic and abdominal organs; a cystoscopy involving examination with the use of a flexible telescope inserted into the urethra, and blood tests to check for urinary tract infections, anaemia, or renal failure.

Treatment of Oliguria will depend on its cause. For most patients, the decrease in urine output may be improved and even reversed. One method of treatment for temporary Oliguria is the insertion of a catheter in the urethra to assist in freeing urine obstruction, and to measure a patient's urine production.

In some cases, hospitalization may be necessary where fluids are administered to the patient through an intravenous drip if the patient is dehydrated. Medications that are toxic to the kidneys are ceased or changed, and if the patient exhibits kidney failure, the doctor may recommend dialysis.