Acute Urinary Retention

An acute inability to urinate when the bladder is full. Acute urinary retention (AUR) is often, but not always, painful. The distended bladder may be palpable and percussible. AUR is distinct from chronic urinary retention, a condition in which patients can still void but chronically retain a significant volume of urine in the bladder after voiding. ¹ Chronic urinary retention is not painful.

Synonyms

AUR

Urinary retention

Retaining urineView full size

ICD-10CM CODES
R33	Retention of urine
R33.8	Other retention of urine
R33.9	Retention of urine, unspecified

Epidemiology & Demographics

Incidence

• •One of the most common urologic emergencies.
• •Typically occurs in aging men, especially those older than 60 yr. However, it may occur in any age group and in either sex. ¹²³
• •Over a 5 yr period, AUR will occur in 10% of men older than 70 yr and in one third of men older than 80 yr. There is a near-linear increase in age-specific incidence for men ages 40 to 80 yr. ^1 , 2

Prevalence

Estimates are 40/100,000 men and 3/100,000 women. Prevalence increases as average lifespan increases. ^1 , 2

Genetics

None known.

Physical Findings & Clinical Presentation

• •Acute inability to pass urine or the tendency to pass only small amounts of urine.
• •Pain and/or pressure in the lower abdomen and suprapubic region is typical. Low back pain may also occur. Pain may be absent, especially in older adults, patients with underlying neurologic disorders, and during chronic urinary retention. ^1 , 2
• •Palpable and/or percussible bladder may be detected during abdominal examination in the suprapubic region.
• •Suprapubic or bladder tenderness with deep palpation may be elicited.
• •Increased urge to urinate with palpation of bladder (pressure applied to suprapubic region).
• •Rarely, flank pain and costovertebral angle tenderness are present when high bladder pressures are transmitted to the ureters and kidney.
• •Increased severity of lower urinary tract symptoms (LUTS) is associated with increased AUR risk. Patients may complain of worsening LUTS prior to episode, including increased urinary urgency, incontinence, nocturia, stranguria, hesitancy, and intermittency. These symptoms usually develop between 1 day and a few wk prior to AUR. ¹
• •Patients with cognitive deficits or inability to communicate may present with restlessness, discomfort, confusion, and/or delirium.
• •Acute kidney injury, electrolyte abnormalities, nausea, and lower extremity edema may be present with delayed presentation. ^1 , 345

Etiology

• •AUR may be spontaneous or precipitated by a triggering event. Spontaneous AUR may arise from the natural progression of bladder outlet obstruction, more commonly from benign prostatic hyperplasia (BPH) and less commonly from pelvic masses and urethral stricture disease. Conversely, precipitated AUR episodes have an identifiable triggering event, such as acute trauma, surgical procedures (e.g., spinal, orthopedic, and urologic), medications (e.g., over-the-counter antihistamines and sympathomimetic agents commonly found in cough medications, anticholinergic drugs, and opioids), excessive fluid intake (e.g., alcohol), urinary tract infection, central nervous system insults (e.g., strokes, hemorrhage, spinal cord injuries), and severe constipation. There is overlap between spontaneous and precipitated AUR, particularly when triggering events are superimposed on underlying obstructive risk factors. ^1 , 2
• •Urinary retention generally results from one of three categories: (1) Increased bladder outflow obstruction, as seen in BPH, urethral stricture disease, extrinsic compression from malignancy, constipation, and in gross hematuria where large clots can obstruct the urethra or bladder neck; (2) disruption of detrusor muscle innervation in association with diabetic neuropathy, spinal cord injury, progressive neurologic pathologies, and bladder contractile dysfunction and decompensation secondary to prolonged outlet obstruction; and (3) bladder overdistension that leads to impaired contractility and may result from general anesthesia, epidural anesthesia, or anticholinergic use. ^1 , 2
• •Acute retention is often multifactorial in older patients, with an underlying obstructive risk factor and an acute precipitant.
• •In women, obstructive factors can include benign tumors (especially fibroid tumors); malignant tumors of pelvic, urethral, or vaginal origin; urethral strictures and urethral meatal stenosis; postpartum vulvar edema; and labial fusion. Pelvic organ prolapse, including cystocele, rectocele, and uterine prolapse, can also lead to urinary retention. ^1 , 6
• •Infection including prostatitis, urethritis, cystitis, genital herpes, and herpes zoster may also produce AUR.
• •AUR is common in the postoperative period when patients are less mobile, are constipated, or have received opioid medications. ^1 , 2

 Diagnosis

Differential Diagnosis

• •AUR is typically self-evident to the cognitively intact patient and the treating physician.
• •Chronic urinary retention.
• •Pelvic masses, fluid collections, uterine fibroids, pregnancies, or ascites may be confused for a full bladder, particularly when using bedside ultrasonic bladder capacity-measuring instruments.

Workup

• •History is focused on urologic symptoms: Dysuria, hematuria, baseline voiding symptoms (caliber and force of stream, nocturia, sensation of incomplete emptying, double-voiding, incontinence, hesitancy), past episodes of retention, surgical history (urologic and other surgical procedures, particularly recent ones), pelvic/perineal trauma, and urologic cancer.
• •History should include a complete list of prescribed and over-the-counter medications and recent medication changes.
• •Review of symptoms should include presence of fever, back pain, neurologic symptoms, and rash.
• •Rectal examination for masses, fecal impaction, perineal and perianal sensation, prostate size, and sphincter tone.
• •Genitourinary examination in men, with special attention for meatal stenosis and phimosis or paraphimosis.
• •Pelvic examination in women to assess for evidence of pelvic organ prolapse(s).
• •Neurologic examination, with particular evaluation for “saddle” anesthesia (i.e., cauda equina syndrome) and pelvic sensory or motor deficits to rule out an underlying neurologic cause.

Laboratory Tests

• •Electrolytes, blood urea nitrogen (BUN), and serum creatinine.
• •Urinalysis and culture obtained via bladder or suprapubic catheterization.
• •Prostate-specific antigen (PSA) testing is not helpful in AUR and may be falsely elevated after catheter placement. This test should not be routinely checked in the acute setting. ¹

Imaging Studies

• •Bladder ultrasound or a bedside postvoid residual urine scan (bladder scan) can be diagnostic. Ascites, pelvic fluid collections, body habitus, and presence of surgical implants (e.g., reservoirs for inflatable penile prostheses or artificial urinary sphincters) may confound accurate volume measurement with these devices. ^1 , 3
• •Abdominal ultrasound or computed tomography (CT) may be helpful if there is suspicion of a pelvic mass.
• •CT ( Fig. 1 ) can be helpful when high volumes are measured by a bedside bladder scan, but low volumes are returned upon bladder catheterization.FIG. 1Large volume urinary retention.Computed tomography images of coronal view (A) and sagittal view (B) of greatly distended bladder. The bladder extends into the midabdomen and above the pubic symphysis. More than 2 liters of urine were drained on bladder catheterization.
• •Magnetic resonance imaging (MRI) should be obtained when a spinal cord problem is suspected.
• •Renal ultrasound or abdominopelvic CT may be obtained when there is kidney functional impairment and/or hydronephrosis is suspected.
• •Evaluation of bladder function by urodynamic testing may be conducted after initial management, particularly in women with no evidence of anatomic obstruction or in patients with longstanding obstruction and/or other neurologic conditions that affect bladder contractility.
• •X-rays are of limited utility in evaluating AUR, but may show underlying constipation.

 Treatment

Acute General Rx

• •Prompt bladder decompression and drainage is the initial management of AUR, generally by indwelling urethral catheterization. Coude-tip (angled-tip) catheters can facilitate catheter placement in men with large prostates. ^{1 , 3 , 4} Clean intermittent catheterization is an option for patients with sufficient dexterity, vision, and motivation.
• •Urologic consultation is advised after recent genitourinary surgery or a history of urethral stricture disease or difficult urethral catheterizations.
• •When urethral catheterization is not possible or is contraindicated, suprapubic catheter placement is required. ^{1 , 3 , 5}
• •Postdecompression hematuria may develop shortly after bladder drainage from small vessel injury of the overstretched bladder wall. This complication is usually self-limiting. ^1 , 4
• •Monitor for postobstructive diuresis that results from a mixed osmotic and saline diuresis from salt and urea accumulation during the period of obstruction. ^1 , 4
• •Avoid and/or discontinue medications that precipitate AUR (e.g., narcotics, anticholinergics, antihistamines).

Chronic Rx

• •A voiding trial is reasonable 5 to 7 days after relief of obstruction in most patients.
• •α-Blockers are effective for treatment of BPH symptoms in men. These agents increase the success rate of early catheter removal and should be initiated, unless contraindicated. There is limited evidence to suggest benefit in women. ¹
• •If feasible, discontinue medications that increase the risk of AUR.
• •Correct constipation and increase patient mobility.
• •Inability to void after 5 to 7 days of catheterization mandates urologic consultation with more intensive evaluation of AUR, including possible cystoscopic evaluation and/or urodynamic studies.
• •For patients who are unable to void after a voiding trial, either initiate clean intermittent catheterization, often two to three times a day, or have the urinary bladder catheter replaced. ¹

Disposition

• •Patients can be discharged home when close follow-up is feasible and progressive kidney injury and postobstructive diuresis are absent. ^1 , 345
• •Hospital admission if patients have the following: Sepsis; complicated urinary tract infection; acute kidney injury; severe postobstructive diuresis; hyperkalemia; acidemia or azotemia; or if AUR is from malignancy, hematuria, or spinal cord compression. ^1 , 345

Referral

• •Urologist, if initial bladder catheterization is unsuccessful, or in surgical scenarios of radical prostatectomy, transurethral resection of prostate, urethral stricture surgery, and other bladder/prostate surgeries
• •Urologic referral for recurrent AUR in men
• •Gynecologic referral is mandatory if a pelvic mass is identified as etiology of AUR in women.

 Pearls & Considerations

• •AUR is often painful.
• •Rapid bladder drainage is of paramount importance.
• •Monitor for postobstructive diuresis and correct electrolyte abnormalities.
• •Request urologic advice or referral for AUR after urologic surgery.

Prevention

• •Avoid and/or treat constipation.
• •Avoid and/or discontinue medications that precipitate AUR (e.g., narcotics, anticholinergics, antihistamines).
• •Patients with BPH should be cautious regarding medications that may precipitate AUR, including antihistamines, sympathomimetics, sedatives, and anticholinergics. On a chronic basis, 5-α reductase inhibitors (e.g., finasteride, dutasteride) may reduce the risk of AUR in men with BPH and large prostates.

Related Content

Benign Prostatic Hyperplasia (Related Key Topic)

References

1.Roehrborn C.G., et al.: Benign prostatic hyperplasia: etiology, pathophysiology, epidemiology, and natural history . In Partin A.W., et al. (eds): (eds) Campbell-Walsh-Wein urology ., ed 12 2021. Elsevier , Philadelphia pp. 3305-3402.

2.Oelke M., et al.: Acute urinary retention rates in the general male population and in adult men with lower urinary tract symptoms participating in pharmacotherapy trials: a literature review . Urology 2015; 86: pp. 654.

3.Marshall J.R., et al.: An evidence-based approach to emergency department management of acute urinary retention . Emerg Med Pract 2014; 16 (1):

4.Halbgewachs C., Domes T.: Postobstructive diuresis: pay close attention to urinary retention . Can Fam Physician 2015; 61: pp. 137.

5.Sliwinski A., et al.: Acute urinary retention and the difficult catheterization: current emergency management . Eur J Emerg Med 2016; 23: pp. 80.

6.Mevcha A., Drake M.J.: Etiology and management of urinary retention in women . Ind J Urol 2010; 26: pp. 230.