Acute bilateral obstructive uropathy is a sudden blockage of the flow of urine from both kidneys, which can cause the backup of urine and kidney injury.

Alternative Names

Urethral obstruction; Acute urethral obstruction; Obstructive uropathy - bilateral - acute

Causes, incidence, and risk factors

Obstructive uropathy occurs when the flow of urine is blocked. The kidneys produce urine in the normal manner but the urine does not drain properly because of the obstruction. Pressure in the urinary tract rises, resulting in hydronephrosis (swelling of the kidneys) and bilateral obstructive uropathy (damage to both kidneys caused by obstruction of urine). Obstructive uropathy may eventually lead to hypertension and/or acute renal failure . Sudden blockage causes acute bilateral obstructive uropathy, while slow, progressive blockage causes chronic bilateral obstructive uropathy . Acute bilateral obstructive uropathy is usually caused by obstruction of the urethra that occurs suddenly or over a short time. In men, it is most often a result of an enlarged prostate. Other causes in men include prostate cancer, bilateral obstructing kidney stones and bladder cancer. It is much less common in women but can occur as a result of a bladder cystocele , pregnancy and iatrogenic (caused by treatment) injury due to surgery involving the female reproductive organs. Other causes include posterior urethral valves in infant boys, neurogenic bladder, papillary necrosis, coagulated blood, fungus and other rare retroperitoneal processes. Initially, the bladder reacts to the obstruction through increased irritability. There is a stronger and more frequent urge to urinate , and bladder spasms or incontinence may occur. As urine accumulates, it may lead to stasis of urine and urinary tract infections (see UTI - acute ). Urine may back up into the ureters (tubes which carry urine from the kidneys to the bladder) and kidney. Symptoms develop because of urinary retention and/or damage to the bladder, ureters and kidneys. Acute bilateral obstructive uropathy occurs in about 5 out of 10,000 people.

Signs and tests

Examination by touch (

palpation ) shows enlarged and tender kidneys. Palpation over the bladder shows bladder distention . Placement of a catheter in the bladder may relieve the lack of urine output. Post-void residuals (catheterized measurement of the volume of urine that remains in the bladder after urinating) are repeatedly more than 50 mL. Rectal examination usually shows an enlarged prostate in men. Blood pressure may be elevated. There may be signs and symptoms of acute renal failure . Fever with infection is common.

A

urinalysis may be abnormal.

A

clean catch urine specimen may show infection within the urinary tract.

Serum creatinine

may increase suddenly, by 2 mg/dL or more over a two-week period.

Creatinine clearance

may be decreased.

Blood

BUN may increase suddenly.

A blood

potassium test may be elevated.

Arterial blood gas

and

blood chemistries may show metabolic acidosis . Hydronephrosis may be apparent in any of the following tests:

IVP

Renal scan

Ultrasound of the kidneys

Abdominal CT scan

This disease may also alter the results of the following tests:

Radionuclide cystogram

Creatinine - urine

Treatment

Treatment is focused on relieving the obstruction, which will allow urine to drain from the urinary tract. This allows the body to begin the natural healing process.

Catheterization may provide short-term relief of symptoms. This may be 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 need to be given upon diagnosis of infection or renal failure. Initial evaluation and treatment may require hospitalization. Long-term relief is accomplished through correction of the cause of the obstruction. Surgical reduction of the prostate, such as by a TURP ( transurethral resection of the prostate ), corrects an enlarged prostate. Surgical intervention may also be appropriate for other disorders causing blockage of the urethra or bladder neck.

Expectations (prognosis)

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

Complications

UTI

Acute renal failure

High blood pressure

Reflux nephropathy

Chronic bilateral obstructive uropathy

Voiding dysfunction (urinary retention/incontinence)

Calling your health care provider

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 the patient is found to have acute obstructive uropathy, he or she should go to the nearest emergency room and urological consultation is required.