David M. Lawson, MD
Acute urinary retention is characterized by a sudden inability to void. It often presents with suprapubic pain and severe urgency. There is usually a history of preexisting obstructive voiding symptoms related to bladder outlet obstruction or poor detrusor function.
Benign prostatic hyperplasia is the most common cause of acute urinary retention in men over the age of 50.
Patients present with progressively worsening voiding difficulties, resulting in bladder overdistention and subsequent urinary retention.
Prostate size on digital rectal examination has no bearing on the degree of outlet obstruction because minimal enlargement of the prostate can cause significant obstruction in some patients and significant enlargement may cause no symptoms.
Prostate cancer accounts for 25% of patients with acute urinary retention. Ten percent of patients with prostate cancer initially present with bladder outlet obstruction.
Additional causes of acute urinary retention include urethral strictures, bladder neck contractures, bladder stones, and acute bacterial prostatitis.
Acute urinary retention may be caused by prolonged obstruction, diabetes mellitus, neurologic disorders (spinal cord injury, herniated vertebral disk), and medications.
Urinary retention after surgery sometimes temporarily develops in elderly men. A preexisting bladder dysfunction or outlet obstruction is usually present.
Anticholinergic medications (antihistamines, antidiarrheals, antispasmodics, tricyclic antidepressants) can suppress bladder function. Sympathomimetic drugs (decongestants and diet pills) that cause contraction of the bladder neck can precipitate an increase in outlet resistance.
Complications of acute urinary retention
Bladder mucosal hemorrhage
Autonomic bladder hyporeflexia
Clinical evaluation of acute urinary retention
Retention is characterized by an inability to void and suprapubic discomfort. A progressive history of difficulty voiding and irritative voiding symptoms, such as frequency, nocturia, or urgency is often noted.
Some patients are incontinent as a result of extreme overdistention of the bladder. A past history of gonorrhea or trauma, underlying diseases and medications should be sought.
Palpate for a distended bladder and assess size and consistency of the prostate. Tenderness of the prostate on rectal examination suggests acute prostatitis; a diffusely hard or nodular prostate suggests carcinoma.
The penis should be examined to rule out phimosis, paraphimosis, or meatal stenosis. A neurologic exam should include anal sphincter reflex and perineal sensation.
Laboratory evaluation. Serum electrolytes, blood urea nitrogen (BUN), creatinine, urinalysis, and urine culture.Management of acute urinary retention
The entire bladder contents should be drained with a Foley catheter. Adequate volume replacement is necessary to prevent hypotension.
Lubrication with 2% lidocaine jelly (injected directly into the urethra with a syringe) will facilitate insertion of a urethral catheter. Medium-sized catheters (#18 to #22 French) should be used because they tend to be stiffer and easier to insert than smaller ones.
In patients with large prostates, Coude! catheters, which have a curved tip, may be helpful. The curve of the Coude! catheter should be directed superiorly. Other methods of drainage include urethral sounds, filiforms with followers, and percutaneous suprapubic tubes.
Admission to the hospital is not required for most patients with acute urinary retention unless infection or renal failure are present. Most patients can be managed with a Foley catheter and discharged home with oral antibiotics and a leg urine bag.Complications of acute urinary retention
Postobstructive diuresis can occur; therefore, fluid and electrolyte balance should be monitored closely.
If significant post-drainage hemorrhage occurs, continuous bladder irrigation should be initiated.
Hypotension may result from either hypovolemia or a vasovagal reaction. However, it can be prevented by adequate volume replacement.
Other complications of urinary retention include sepsis and renal failure due to longstanding obstruction.
Testicular torsion is an emergency, and any delay in treatment may result in testicular loss. A four- to six-hour delay may impair normal testicular function.
Torsion can occur at any age; however, it is most common in adolescents, peaking at the age of 15 to 16 years.
Testicular torsion presents with sudden onset of pain and swelling in one testicle, occasionally associated with minor trauma. There is frequently nausea, vomiting, and lower abdominal or flank pain. There may be a history of previous similar episodes with spontaneous resolution.
A urinalysis is essential in differentiating testicular torsion from epididymitis; however, a negative urinalysis does not rule out epididymitis.Differential diagnosis of testicular torsion
Epididymitis due to Neisseria gonorrhoeae and Chlamydia trachomatis is much more common than torsion in adult men.
Torsion of an appendix testis or appendix epididymis may mimic testicular torsion. Torsion of the appendix testis may manifest as a tender, pea-sized nodule at the upper pole of the testicle with a small blue-black dot seen through the scrotal skin (the blue dot sign). Management is conservative; however, if there is diagnostic uncertainty, surgical exploration is required.
Other less common conditions that may present similarly to torsion include acute hemorrhage into a testicular neoplasm, orchitis, testicular abscess, incarcerated hernia, and testicular rupture.Physical examination
Testicular torsion usually presents with severe unilateral testicular pain with an acute onset. The pain is associated with an extremely tender testicle with a transverse lie or an anterior epididymis that lies high in the scrotum.
The testis is high in the scrotum (Brunzel's sign). The presence of a cremasteric reflex almost always rules out testicular torsion.
Relief of pain by elevation of the affected testis (Prehn's sign) suggests epididymitis. A negative Prehn's sign suggests testicular torsion.Diagnostic imaging
Diagnostic testing should not delay surgical exploration in acute torsion. If the diagnosis is unclear, diagnostic tests may be useful.
Color Doppler ultrasound is the most valuable diagnostic study, with nearly 100% sensitivity and specificity.Management of testicular torsion
Immediate detorsion is imperative for all cases of testicular torsion. Testicular salvage rates decrease to 50% at 10 hours and to 10-20% at 24 hours.
Manual detorsion can be attempted as an urgent measure by rotating the testicle medially about its pedicle. Surgical orchiopexy is still required.
If an infarcted testicle is noted during surgical exploration, it should be removed. If the testicle is viable, both testicles should be fixed in the scrotum with nonabsorbable sutures.
Priapism is defined as a prolonged penile erection. Most cases of priapism in adults are idiopathic. In children the most common causes are sickle cell anemia, hematologic neoplasms (leukemia), and trauma.Evaluation of priapism
Patients usually complain of a persistent, painful erection. They may have fever and voiding difficulties.
Physical examination should include a neurologic evaluation and perineal inspection for neoplasms. Examination of the penis usually reveals a flaccid glans despite rigid corpora cavernosa.
Hematologic studies should be performed to rule out sickle cell anemia and leukemia.Treatment of priapism
Early treatment reduces the risk of long-term impotence, which may occur in 50%. Discomfort can be reduced with parenteral narcotic analgesics and sedation.
Detumescence may be achieved using cold compresses, ice packs, warm- or cold-water enemas, and prostate massage.
If these treatments are unsuccessful, the static blood may be aspirated from the corpora using a large bore needle. Followed by irrigation of the corpora with saline containing a vasoconstricting agent (phenylephrine, epinephrine, or metaraminol).
If this process fails to achieve detumescence, a shunt may be created between the affected corpora cavernosa and unaffected corpus spongiosum with a Tru-Cut biopsy needle.
When priapism is secondary to sickle cell anemia, therapy also includes hydration, oxygen, and blood transfusion.