URINARY OBSTRUCTION By: d. hana omer .

Incidence Frequency Sex No data available in unselected populations 20-35% prevalence in large survey among elderly men 3.8% (adults); 2.0% (children) postmortem examinations Sex No gender difference until 20 years Women 20-60; Men > 60 No data are available on incidence and prevalence of urinary obstruction in unselected populations. Most epidemiologic studies of obstruction are in selected populations or autopsy studies. In large surveys of elderly men for symptoms of urinary obstruction, a prevalence of 20-35% has been estimated. Postmortem examinations have found hydronephrosis in 3.8% of adults and 2.0% of children. Sex In adults, incidence and etiology of urinary obstruction vary significantly with the age and sex of the patient. In young and middle-aged men, renal calculi are the most common cause of at least temporary urinary obstruction. Rare cases of obstructive uropathy due to seminal vesicle cyst and appendiceal mucocele have been reported. In young and middle-aged women, gynecologic surgery, pregnancy, and cancers of pelvic organs are important etiologies of obstruction. After age 60 years, urinary obstruction is most common in men secondary to prostatic hypertrophy; prostate cancer accounts for occasional cases. Age Special considerations in pediatric patients include acquired or congential urethral stricture, congenital ureteropelvic junction (UPJ) or ureterovesical junction (UVJ) obstruction, vesicoureteral reflux, and urolithiasis.

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.

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.

Etiology Types of obstruction Mechanical blockade Functional defects Intrinsic extrinsic Functional defects Congenital Obstruction to urine flow can result from intrinsic or extrinsic mechanical blockade as well as from functional defects not associated with fixed occlusion of the urinary drainage system. Mechanical obstruction can occur at any level of the urinary tract, from the renal calyces to the external urethral meatus. Normal points of narrowing, such as the ureteropelvic and ureterovesical junctions, bladder neck, and urethral meatus, are common sites of obstruction. When blockage is above the level of the bladder, unilateral dilatation of the ureter (hydroureter) and renal pyelocalyceal system (hydronephrosis) occur; lesions at or below the level of the bladder cause bilateral involvement.

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 blood chemistry profile

An X ray of a blocked ureter An X ray of a blocked ureter. The ureters are muscular tubes that carry urine from the renal pelvis in each kidney to the 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   Liberal fluids to produce two litres of urine per day      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.