Benign prostatic hyperplasia
Benign prostatic hyperplasia: Excerpt from Handbook of Diseases
Although most men older than age 50 have some prostatic enlargement, with benign prostatic hyperplasia (BPH), the prostate gland enlarges sufficiently to compress the urethra and cause some overt urinary obstruction. Depending on the size of the enlarged prostate, the age and health of the patient, and the extent of obstruction, BPH is treated symptomatically or surgically.
Causes
Recent evidence suggests a link between BPH and hormonal activity. As men age, production of androgenic hormones decreases, causing an imbalance in androgen and estrogen levels and high levels of dihydrotestosterone, the main prostatic intracellular androgen. Other causes include neoplasm, arteriosclerosis, inflammation, and metabolic or nutritional disturbances.
Whatever the cause, BPH begins with changes in periurethral glandular tissue. As the prostate enlarges, it may extend into the bladder and obstruct urinary outflow by compressing or distorting the prostatic urethra. BPH may also cause a pouch to form in the bladder that retains urine when the rest of the bladder empties. This retained urine may lead to calculus formation or cystitis.
Signs and symptoms
Signs and symptoms of BPH depend on the extent of prostatic enlargement and the lobes affected.
Urinary symptoms
Characteristically, the condition starts with a group of symptoms known as prostatism: reduced urinary stream caliber and force, difficulty starting micturition (straining), feeling of incomplete voiding and, occasionally, urine retention. As obstruction increases, urination becomes more frequent, with nocturia, incontinence and, possibly, hematuria.
Physical examination reveals a visible midline mass (distended bladder) that represents an incompletely emptied bladder; rectal palpation discloses an enlarged prostate. The examination may also detect secondary anemia and, possibly, renal insufficiency secondary to obstruction.
Later effects
As BPH worsens, complete urinary obstruction may follow infection. Complications include infection, renal insufficiency, hemorrhage, and shock.
Diagnosis
Signs and symptoms and a rectal examination are usually sufficient for a diagnosis. Other test findings help to confirm it.
❑ Excretory urography may indicate urinary tract obstruction, hydronephrosis, calculi or tumors, and filling and emptying defects in the bladder.
❑ Elevated blood urea nitrogen and serum creatinine levels suggest impaired renal function.
❑ Urinalysis and urine culture show hematuria, pyuria and, when the bacterial count exceeds 100,000/µl, urinary tract infection.
With severe symptoms, a cystourethroscopy is definitive, but this test is performed only immediately before surgery to help determine the best procedure. It can show prostate enlargement, bladder wall changes, and a raised bladder.
Treatment
Treatment depends on the cause, severity of the obstruction and the status of the patient. Conservative therapy includes prostate massages, sitz baths, fluid restriction for bladder distention, and an antimicrobial for infection. Regular ejaculation may help relieve prostatic congestion.
Urine flow rates can be improved with alpha-adrenergic blockers, such as terazosin, tamsulosin, and prazosin. These drugs relieve bladder outlet obstruction by preventing contractions of the prostatic capsule and bladder neck. Finasteride may also reduce the size of the prostate in some patients.
Surgery is the only effective therapy to relieve acute urine retention, hydronephrosis, severe hematuria, recurrent urinary tract infections, and other intolerable signs and symptoms. (See Combating septic shock after prostate surgery.)
A transurethral resection may be performed if the prostate weighs less than 2 oz (57.2 g). In this procedure, a resectoscope removes tissue with a wire loop and electric current. In high-risk patients, continuous drainage with an indwelling urinary catheter alleviates urine retention.
Alternatively, large prostates can be removed by one of two surgical approaches:
❑ suprapubic (transvesical) resection: most common and useful when prostatic enlargement remains within the bladder
❑ retropubic (extravesical) resection: allows direct visualization; potency and continence are usually maintained.
Balloon dilatation of the prostate is ineffective. Transurethral microwaves (heat therapy) are now being used in some patients. Their efficacy lies between that of the use of an alpha1-adrenergic blocker and surgery.
Special considerations
❑ Monitor and record the patient’s vital signs, intake and output, and daily weight. Watch closely for signs of postobstructive diuresis (such as increased urine output and hypotension), which may lead to serious dehydration, lowered blood volume, shock, electrolyte loss, and anuria.
❑ Administer an antibiotic, as needed, for urinary tract infection, urethral instrumentation, and cystoscopy.
❑ If urine retention is present, insert an indwelling urinary catheter (usually difficult to do in a patient with BPH). If the catheter can’t be passed transurethrally, assist with suprapubic cystostomy (under local anesthetic). Watch for rapid bladder decompression.
After prostate surgery, perform the following:
❑ Maintain patient comfort, and watch for and prevent postoperative complications.
❑ Observe the patient for immediate dangers of prostatic bleeding (shock and hemorrhage). Check the catheter frequently (every 15 minutes for the first 2 to 3 hours) for patency and urine color; check the dressings for bleeding.
❑ Many urologists insert a three-way catheter and establish continuous bladder irrigation. Keep the catheter open at a rate sufficient to maintain returns that are clear and light pink.
❑ Watch for fluid overload from absorption of the irrigating fluid into systemic circulation. If a regular catheter is being used, observe it closely. If drainage stops because of clots, irrigate the catheter, usually with 80 to 100 ml of normal saline solution, while maintaining strict aseptic technique.
❑ Also watch for septic shock, the most serious complication of prostate surgery.
❑ Administer belladonna and an opium suppository or another anticholinergic, as needed, to relieve painful bladder spasms that can occur after transurethral resection.
❑ After an open procedure, provide suppositories (except after perineal prostatectomy), an analgesic to control incisional pain, and frequent dressing changes.
❑ Continue infusing fluids I.V. until the patient can drink a sufficient amount (2 to 3 qt [2 to 3 L] per day) to maintain adequate hydration.
❑ Administer a stool softener and a laxative, as required, to prevent straining. Don’t check for fecal impaction: A rectal examination could precipitate bleeding.
❑ After the catheter is removed, the patient may experience urinary frequency, dribbling, and occasional hematuria. Reassure him that he’ll gradually regain urinary control. Explain this to the patient’s family so they can also reassure the patient.
❑ Reinforce prescribed limits on activity. Warn the patient against lifting, strenuous exercise, and long automobile rides because these increase bleeding tendency. Also, caution him to restrict sexual activity for at least several weeks after discharge. As appropriate, inform him that retrograde ejaculation, in which the seminal fluid goes into the bladder and is excreted in urine, can occur after some types of prostate surgery.
❑ Instruct the patient to follow the prescribed oral antibiotic regimen, and tell him the indications for using gentle laxatives. Urge him to seek medical care immediately if he can’t void, if he passes bloody urine, or if he develops a fever.
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Book Source Details
- Book Title: Handbook of Diseases
- Author(s): Springhouse
- Year of Publication: 2003
- Copyright Details: Handbook of Diseases, Copyright © 2003 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: Handbook of Diseases
Authors: Springhouse
Publisher: Lippincott Williams & Wilkins
Copyright: 2003
ISBN: 1-58255-266-5
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