Benign prostate disease
VOL: 98, ISSUE: 28, PAGE NO: 53
Vanessa Basketter, BSc, RGN, Dip(HE), is uro-oncology clinical nurse specialist, St Mary's Hospital, PortsmouthThe prostate is a chestnut-sized gland present in men. It is situated at the base of the bladder, surrounding the urethra like a doughnut. Once a man reaches middle age, the prostate grows and is a potential source of disease and disability (Bott and Kirby, 2002).
There are three anatomical zones that form the prostate: the central, transition and peripheral zones (Fig 1). Benign prostatic hyperplasia develops in the transition zone, which lies in the middle of the gland. It is the enlargement of this zone that causes pressure on the urethra, leading to bladder outflow obstruction and hence a variety of lower urinary tract symptoms. Benign prostatic hyperplasia can have a great impact on the patient's quality of life and may also affect his partner. It is this nuisance factor that pushes men to seek assistance. In the majority of men the progression of benign prostatic hyperplasia is slow and often perceived as a natural sign of aging. In fact, the only definite risk factor to developing benign prostatic hyperplasia is the aging process and normal testicular function (Bott and Kirby, 2002). Other suggested risk factors, such as diet, alcohol, diabetes, obesity and smoking have been suggested but never confirmed. Signs and symptoms
Most nurses can identify the most common symptoms of benign prostatic hyperplasia. The nurse can rule out the possibility of infection causing these symptoms by a simple urine dipstick test. There are a number of symptoms of prostate disease that nurses need to be aware of. They can be split into two main categories (Table 1). Most men with bladder outflow obstruction complain of a mixture of both irritative and obstructive symptoms. However, if irritative symptoms predominate this may be an indication that there is another cause for the symptoms. Other pathologies must be excluded by cystoscopy and urodynamic investigations before a diagnosis of benign prostatic hyperplasia can be made (Table 2). Acute urinary retention
Benign prostatic hyperplasia can also present more suddenly with acute urinary retention. The incidence of acute urinary retention increases with age from 1.6% at 40 to 10% for 70-year-old men (Jacobsen et al, 1997). Patients often present with acute urinary retention either as an emergency admission or as a postoperative complication following surgery. Retention of urine occurs when the urethra becomes so obstructed that the bladder is unable to void normally. Investigations
There is no one investigation that can be used to diagnose bladder outflow obstruction. It is because of this that prostate assessment clinics have been set up in urology departments across the country. Theses are usually nurse-led clinics providing detailed investigations of this condition. Most clinics follow guidelines and include the following investigations: - Flow rate - used to determine the strength and degree of obstruction of the urinary flow; - Postmicturition residual volume - performed with an ultrasound machine or bladder scanner to detect the amount of urine left behind after micturition; - Digital rectal examination - a rectal examination by a finger to assess the size and firmness of the prostate and checking for tenderness; - International prostate symptom score - a symptom-based questionnaire to determine the primary cause of the lower urinary tract symptoms. It includes a quality of life question to determine how bothersome these symptoms are. However, the score cannot identify the degree of obstruction; - Renal function - blood is taken to assess renal function. A lower urinary tract obstruction can give rise to hydronephrosis; - Prostatic specific antigen - used to identify the possible risk of prostate cancer being present. This test is unable to diagnose prostate cancer; - Detailed medical and drug history - other causes for urinary symptoms must be excluded - for example, diabetes or neurological disease. Many of these clinics are now independent of medical responsibility. Nurses provide a possible diagnosis and advice regarding treatment, with a care management plan being returned to the GP. Urgent cases can be directly referred to a urologist. Treatment
There are three main treatment options for benign prostatic hyperplasia - watchful waiting, medical therapy and surgical intervention. The decision on what treatment to prescribe depends on the severity of symptoms, the effect the symptoms are having on the patient, the presence of co-morbidity and the wishes of the patient. Watchful waiting Some patients presenting with lower urinary tract symptoms are not particularly troubled by them. Once other pathologies are ruled out, it is appropriate to adopt a watch-and-wait policy. Men are seen and assessed either by their GP or by the urology department, depending on the severity of their symptoms. Medical management Medical management is fast becoming the first choice for men presenting with bladder outflow obstruction from benign prostatic hyperplasia. In recent years the development of selective medication has meant that the medical option has become a more popular choice. There are two main class of drug used to treat benign prostatic hyperplasia: - Alpha-blockers (indoramin, alfuzosin, doxazosin) - these work by relaxing the muscles of the bladder neck and prostatic urethra, overcoming the obstruction and increasing the flow of urine. Approximately 60% of men will have a significant improvement in their symptoms within two to three weeks (Kirby 2000). Possible side-effects include tiredness, dizziness, headache and delayed or retrograde ejaculation. Because these drugs act on the smooth muscle they can also cause a reduction in blood pressure. If reduction in blood pressure needs to be avoided then certain alpha-blockers - for example, alfuzosin - are more selective to the urinary tract and less likely to affect blood pressure; - 5 alpha-reductase inhibitor (finasteride) - this acts by inhibiting the enzyme 5 alpha-reductase which converts testosterone to dihydrotestosterone, which is known to play a key role in the control of prostate growth (Kirby, 2000). Finasteride is the only 5 alpha-reductase inhibitor currently available. It also appears to have the ability to reverse benign prostatic hyperplasia in some men, particularly in men with very large prostates (Boyle, 1996). The positive effects of finasteride can take anything from three to 12 months to become apparent, which can discourage some patients from initiating the treatment (Ekmann, 1998). Treatment is well tolerated. Side-effects associated with finasteride are reduced libido and difficulty maintaining erection in about 5% of men. Men taking finasteride should wear a condom during intercourse if their sexual partner is likely to become pregnant, as there is a risk of fetal developmental problems. An additional side-effect of this drug is the reversal of male-pattern balding. Combination therapy It is possible to use both types of drug. However, no studies are available to support this practice. Phytotherapy (plant extracts) There is an increasing range of plant extracts being marketed for prostate disease, saw palmetto being the most popular. Studies have shown it to be effective in men with mild symptoms (Wilt et al, 1998). It has similar side-effects to finasteride - for example, breast tenderness, decreased libido and erectile dysfunction has been reported. Self-management/lifestyle modification Work is currently under way to examine the effectiveness of lifestyle changes in benign prostatic hyperplasia. This is based on commonsense advice, and previous studies have not shown convincing results. Nevertheless, some of these changes can be initiated by experienced urology nurses to help improve lower urinary tract symptoms in patients who have mild to moderate symptoms as first-line therapy (Table 3). Surgery
Surgery is still classed as the 'gold standard' treatment for benign prostatic hyperplasia, but because of the advent of medical therapies the number of transurethral resections of the prostate has halved in the past 15 years (Bott and Kirby, 2002). Advancements in laser, microwave and thermotherapy technology have been introduced, offering non-invasive options. Indications for surgery are bothersome lower urinary tract symptoms, complications of benign prostatic hyperplasia - which include acute retention or renal failure and failure to respond to medical therapy. Transurethral resection of the prostate (TURP) A transurethral resection of prostate cores out the overgrown prostate via the urethra (Fig 2). This can be carried out under either a spinal or general anaesthetic and takes approximately 30 minutes. Men usually stay in hospital for three days and have an indwelling urethral catheter for approximately 24 hours (Fillingham and Douglas, 1997). Eighty per cent of men will experience symptom improvement, but 70% will suffer retrograde ejaculation and 3% urethral stricture. Open prostatectomy This uncommon procedure is appropriate mainly for men with very large prostates. It is an abdominal procedure to remove the whole prostate gland with side effects that include those of TURP but to a greater extent. Microwave This uses microwave energy to destroy prostate tissue. This procedure is carried out via the urethra under local anaesthetic. Lazer ablation This procedure is performed under a general anaesthetic and destroys prostate tissue by laser energy. A catheter is needed for a few days postoperatively. The risk of bleeding is less common than after other surgical procedures. Prostatic stents Stents are used for men unable to tolerate anaesthesia for long periods. They often fail to be as effective as TURP but provide some relief from bladder outflow symptoms. Complications involve problems with stent placement, encrustation and urethral discomfort.