URINARY OBSTRUCTION

By: Beverly Sorreta

ETIOLOGY

A urinary obstruction means the normal flow of urine is blocked. As the urine backs up, it can cause infections in the urinary system, damage the bladder and affect the kidneys. If the kidneys are injured (a condition called hydronephrosis) it can be life threatening.

Obstruction may lead to alterations in blood chemistry; infection that thrives as a result of urine stasis; ischemia due to compression; or atrophy of renal tissue

CLINICAL MANIFESTATIONS

The cause in children may be a birth defect. In children or adults, the urine may be blocked due to scarring along the urinary tract due to injury or infection. In adults, the most common cause is a kidney stone (renal lithiasis). With men, as they age, the most common cause is an enlarged prostate gland. Other causes include tumors, cancers and pregnancy.

The obstruction can involve one or both kidneys, called unilateral or bilateral obstruction. The blockage may be complete or partial. It can occur suddenly (acute) or develop over time (chronic). It varies by location.

UNILATERAL OBSTRUCTION

Signs and symptoms

inability to pass urine (urinary retention) weak stream of urine interrupted stream blood in the urine pain in either flank (side) or in the back abdominal pain and/or swelling

LABS AND DIAGNOSTICS

The physician may order a kidney, ureter, and bladder (KUB) radiograph. Renal ultrasonography or IVP will provide definitive information about structural changes.

Other diagnostic tests may include visual examinations with the aid of endoscopy and a blood chemistry profile

An X ray of a An X ray of a blocked ureter. The blocked ureter. The ureters are ureters are muscular tubes that muscular tubes that carry urine from carry urine from the renal pelvis in the renal pelvis in each kidney to the each kidney to the urinary bladder. urinary bladder.

MEDICAL MANAGEMENT

To establish urine drainage and relieve discomfort

Conservative measures include insertion of an indwelling catheter, analgesic (usually opioid), and an anticholinergic agent (Atropine) to decrease smooth muscle motility

To establish urine drainage, inserting a catheter directly into the bladder through the abdominal wall (suprapubic cystostomy)

CONT…

Into a ureter (ureterostomy), or into the kidney (nephrostomy).

A stent is a tube, use for surgical correction of an obstruction in the urinary system

A mesh-like tube or coil-shaped device is inserted through an endoscope into the ureter

Stent holds the tubular structure open to facilitate drainage.

Nx INTERVENTIONS

Observation for hemorrhage Maintaining aseptic care of surgical site Restoring optimal urinary function Providing a safe environment to prevent

injury and infection

PATIENT TEACHING

 

Liberal fluids to produce two litres of urine per day  Normalise serum uric acid level   Keep urine sterile  A diet without excessive sodium (salty food), calcium

(dairy products), oxalate (nuts) and urates (for example, red meat) 

Avoid excessive intake at dinner (overeating) and extend interval from dinner until retiring for the night 

Urinary alkalinisation with addition of citrate (a stone inhibitor) is helpful in recurrent uric acid or calcium stone-formers

PROGNOSIS

Is variable, depending on the cause of the obstruction.

If surgical correction is successful, the prognosis is excellent.