Acute bilateral obstructive uropathy

Definition

Acute bilateral obstructive uropathy is a sudden blockage of the flow of urine from both kidneys.

Alternative Names

Causes

Obstructive uropathy occurs when the flow of urine is blocked. The kidneys continue to produce urine in the normal manner, but the urine does not drain properly because of the obstruction. This causes swelling of the kidneys (hydronephrosis). A sudden blockage that affects both kidneys causes acute bilateral obstructive uropathy. The condition may eventually lead to hypertension or acute renal failure.

In men, acute bilateral obstructive uropathy is most often a result of an enlarged prostate. Other causes in men include prostate cancer, bilateral obstructing kidney stones and bladder cancer. Acute bilateral obstructive uropathy is much less common in women, but may occur as a result of a bladder cystocele

Acute bilateral obstructive uropathy occurs in about 5 out of 10,000 people.

Symptoms

• Decreased urine output (may be less than 10 mL per day)
• Urinary hesitancy
• Abnormal urine flow -- dribbling at the end of urination
• Incontinence
• Decrease in the force of the urinary stream, stream small and weak
• Increased urinary frequency or urgency
• Need to urinate at night
• Frequent strong urge to urinate
• Burning or stinging with urination
• Feeling of incomplete emptying of the bladder
• Sudden flank pain or pain on both sides
• Blood in the urine
• Fever
• Nausea and vomiting
• High blood pressure (hypertension), recent increase
• Urine, abnormal color

Exams and Tests

A physical exam may show swollen or tender kidneys. The bladder may be large and full. A rectal examination may reveal an enlarged prostate. Signs and symptoms of chronic renal failure may be present. Blood pressure may be high. Fever is common with an infection.

• Urinalysis and a urine culture (clean catch) may show a urinary tract infection.
• Serum creatinine may increase suddenly, by 2 mg/dL or more over a 2-week period.
• A CBC may show an increased white blood cell count  
• A basic metabolic panel will reveal patient's current kidney function as well as electrolyte balance, which may be abnormal. Blood BUN may increase suddenly. Creatinine clearance may be decreased.
• A blood potassium test may be elevated.
• A bladder scan (ultrasound) may show a large amount of urine in the bladder after urinating (more than 50 mL).
• Uroflowmetry may reveal decreased urinary flow due to a swollen prostate (BPH).
• Arterial blood gas and blood chemistries may show metabolic acidosis.

The following tests may show hydronephrosis (swelling of kidneys):

• IVP
• Renal scan
• Ultrasound of the kidneys
• Abdominal CT scan

• Radionuclide cystogram
• Creatinine - urine

Treatment

Treatment is focused on relieving the obstruction, which will allow urine to drain from the urinary tract.

The patient may need to stay in a hospital for a short while.

A tube placed into the body to relieve urine (catheterization) may provide short-term relief of symptoms. Techniques may use a urethral (Foley) catheter, intermittent self-catheterization, or a suprapubic tube (tube directly draining the bladder through the abdominal wall).

Antibiotics or other medications may be given.

Long-term relief is accomplished through correction of the cause of the obstruction.

Surgery such as TURP (transurethral resection of the prostate) or newer techniques that use laser or heat therapy to shrink the prostate may be helpful if the cause of the problem is an enlarged prostate.

Surgery may also be needed for other disorders that cause blockage of the urethra or bladder neck.

Outlook (Prognosis)

If the acute obstruction is quickly relieved, symptoms usually subside within hours to days. If untreated, the disorder causes progressive damage to the kidneys, and may cause kidney failure and death.

Possible Complications

• UTI
• Acute renal failure
• High blood pressure
• Reflux nephropathy
• Chronic bilateral obstructive uropathy
• Voiding dysfunction (urinary retention or incontinence)

When to Contact a Medical Professional

Call your health care provider if decreased urine output, difficulty urinating, flank pain, or other symptoms of acute bilateral obstructive uropathy occur.

Prevention

This disorder may not be preventable in many cases. Routine annual physicals with a primary care physician are recommended. If found to have acute obstructive uropathy, the patient should go to the nearest emergency room and consult a urologist.

Walsh PC. Campbell's Urology. 8th ed. St. Louis, Mo: WB Saunders; 2002:412. 

Goldman L, Ausiello D. Cecil Textbook of Medicine, 22nd ed. Philadelphia, Pa: WB Saunders; 2004:741-742.