Continuing Education Activity

Urinary retention, or the inability to voluntarily void urine, is one of the most prevalent presenting urologic complaints in the emergency department. Typically, it is diagnosed when there is a high post-void residual volume. Post-Void residual volume measurements are usually done using ultrasound and provide an estimate of the amount of urine remaining in the bladder after urination. Two of the most common causes of chronic urinary retention in women are bladder muscle dysfunction and obstruction. The condition is important as it can lead to significant clinical problems if left untreated, such as bladder decompensation, hydronephrosis, renal failure, vesicoureteral reflux, nephrolithiasis, and urinary tract infections, as well as symptoms including suprapubic pain, feelings of incomplete emptying, weak urinary stream, urgency, and incontinence. This activity reviews the evaluation and management of urinary retention in women. It highlights the role of the interprofessional team in collaborating to provide well-coordinated care and enhance outcomes for affected patients.

Objectives:

• Identify the causes of urinary retention in females.
• Review risk factors for urinary retention in females.
• Describe treatment options for urinary retention in females.
• Explain the importance of improving coordination amongst the interprofessional team to enhance care for females affected by urinary retention.

Introduction

Urinary retention is one of the most prevalent urological complaints resulting in patients presenting to the emergency department, although this is typically in men rather than women. It is loosely defined as the inability to pass urine, but a more precise definition is a bit challenging. The best consensus-recommended definition is a complete inability to void spontaneously or persistently elevated post-void residual urine volumes, which would lead to an adverse clinical outcome without any intervention.[1] 

Typically, the diagnosis is made from the finding of a high post-void residual urine volume, often along with symptoms of suprapubic pain or inability to void. Post-void residual urine volume measurements are typically made by using a bladder scanner or ultrasound to estimate the amount of urine remaining in the bladder after urination or by straight catheterization. Patients with acute retention will typically complain of suprapubic pain and inability to void normally, but some patients, particularly the elderly, may be asymptomatic.[2] The normal maximum bladder capacity is about 500 mL, so any amount over this is clearly abnormal and suggestive of urinary retention.

The condition is vital as it can lead to significant clinical problems if left untreated, such as bladder decompensation, hydronephrosis, renal failure, vesicoureteral reflux, nephrolithiasis, and urinary tract infections, as well as symptoms including suprapubic pain, feelings of incomplete emptying, weak urinary stream, urgency, and incontinence.[3]

Etiology

Female urinary retention is either acute or chronic and can be categorized according to the International Continence Society as:

• Complete (full retention) or partial (high post-void residuals)
• Acute or chronic
• Symptomatic or asymptomatic
• Mechanism (obstructive or non-obstructive)
• Bladder pressure: high or low

Female urinary retention is caused by one of four general etiologies: neurological, obstructive, pharmacological, and psychogenic.

A number of etiologies exist for this condition.[4][5][6][7][8][9] Common specific causes include:

• Acute vulvovaginitis
• Anesthesia (general or regional)
• Bladder neck stenosis
• Bladder radiation
• Brain tumor, infection, trauma, or stroke
• Cauda equina syndrome
• Cerebral palsy
• Cervical cancer
• Constipation
• Cystocele
• Cystotomy not recognized during surgery
• Detrusor sphincter dyssynergia
• Diabetes
• Fibroids
• Fowler's syndrome
• Frailty
• Genital herpes
• Heavy metal poisoning
• Iatrogenic nerve injury during pelvic surgery
• Joint replacement surgery
• Meatal stenosis
• Meningomyelocele
• Multiple sclerosis
• Neurologic injury during surgery
• Obstruction from a vaginal hematoma, packing, sling procedures, urethral foreign body, urinary calculi, pelvic organ prolapse, failure of pelvic floor relaxation, etc.
• Older age
• Parkinson disease
• Pelvic injury, trauma, or malignancy
• Pelvic organ prolapse
• Pessary: poorly fitting or out of position
• Pharmacological from long-term use of antihistamines, anticholinergics, overactive bladder medications, opioids, tricyclic antidepressants, antispasmodics, antipsychotics, SSRIs, alpha-adrenergic agonists, etc.
• Polypharmacy
• Rectocele
• Spina bifida
• Spinal cord injury or infection
• Surgery, especially incontinence procedures such as pubovaginal slings
• Urethral cancer
• Urethral diverticula or thrombosed caruncle
• Urethral injury or scarring
• Urethral swelling from infection
• Vaginal childbirth; especially if instruments were required
• Vaginal lichen planus

Aging affects detrusor contraction strength, bladder sensation, and urinary flow rate.[8][10][11] As these age-related changes progress, post-void residual urine volumes increase, and the risk of urinary retention rises. The mechanisms of these changes include an increased ratio of collagen to muscle in the detrusor, a gradual reduction in bladder sensation over time, and a diminishing recognition by the brain of bladder filling.[12][13][14] Interestingly, post-void residual volumes are generally unchanged without other pathology.[11]

Bladder outlet obstruction in women can be caused by pubovaginal sling surgery or pelvic organ prolapse.[15][16] These disorders cause pinching or kinking of the urethra resulting in impaired bladder emptying. External compression of the urethra can also cause similar problems with bladder function. Extrinsic urethral compression is most often the result of constipation, fibroids, tumor mass, or sling surgery. Some fibroids and pelvic tumors may place direct pressure on the pelvic nerves and cause radiculopathy.[17] Urethral cancer can cause incomplete bladder emptying; it is extremely rare.[18] 

While constipation is clearly a cause of incomplete bladder emptying in children, its role in adults is less clear except for fecal impactions. Urethral lesions such as strictures, diverticula, and caruncles can also cause a bladder outlet obstruction. Strictures are usually the result of infections or prior urological procedures such as urethral dilations. It is estimated that urethral strictures may occur in 4% to 13% of women with urinary retention due to bladder outlet obstruction.[19]

Detrusor underactivity is defined as a contraction of reduced strength and/or duration, which results in a failure to empty the bladder adequately within a reasonable period. It generally requires urodynamic testing to make a confirmed diagnosis. The most common causes include pelvic neuropathy, central nervous system disorders, bladder muscle dysfunction, aging, neurological diseases, and medication effects.

Diabetic women are far more likely to have higher post-void residual urine volumes than non-diabetic females due to both motor and sensory neurogenic changes, as more than fifty percent of women with longstanding diabetes will develop peripheral neuropathy.[20][21] Thirty percent of diabetic women will demonstrate detrusor interactivity, and thirteen percent will have a completely atonic bladder.[22] The specific mechanism is that prolonged hyperglycemia induces increased oxidative stress with high cytokine release inside peripheral nerve cells while also interfering with capillary blood flow to the neurons, causing mild ischemia.[23] The result is peripheral neuropathy which often affects bladder function and can result in urinary retention.

Fowler's syndrome is a rare clinical problem that causes urinary retention in young women. First described in 1988, the syndrome usually occurs after menarche in the 2nd to 3rd decades, and there is often a triggering event such as a surgical procedure or an acute illness.[24][25] Before the onset of urinary retention, most patients with Fowler's syndrome have minimal voiding issues, such as an intermittent stream or infrequent micturition.[26]

Fowler's syndrome should be suspected in all younger women with non-neurogenic, non-obstructive urinary retention unrelated to surgery, trauma, or childbirth.[25] It is frequently associated with polycystic ovary syndrome (40%) and opioid use.[27][28] It is thought that hormonal changes associated with polycystic ovary syndrome result in relaxation failure of the female urethral sphincter muscle, causing an overactive, non-relaxing sphincter.[29] This increases urethral afferent activity, which inhibits bladder afferent signaling to the brain resulting in poor bladder sensation and markedly decreased detrusor contractility.[28] These effects potentiate the bladder storage spinal reflex and result in dysfunctional voiding, high residual volumes, and urinary retention. The yearly incidence is reported as 0.2 cases per 100,000 population.[30] Other neurological causes of urinary retention in younger women include multiple sclerosis and spinal cord injury or compression.[29][31]

Fowler's syndrome is characterized by the following characteristics:[25][28] 

• Younger women in 2nd and 3rd decades of life
• Not associated with pelvic surgery or childbirth
• There may have a triggering event such as a surgical procedure or an acute illness
• Often associated with polycystic ovary syndrome (in 40% of cases) and opioid use
• Urinary retention or high post-void residual urine volumes, typically at least 1,000 mL at some point
• Increased bladder capacity
• Decreased bladder sensation
• Markedly reduced bladder contractions and detrusor voiding pressures
• High urethral sphincter closing pressure and muscle tone (usually detectable by urethral sphincter EMG)
• Increased sphincteric volume on transvaginal ultrasound
• Intermittent catheterization is often painful, especially on withdrawal of the catheter

Functional bladder outlet obstruction would involve any abnormal contraction or failure of relaxation of the urethral sphincter during voiding. This would include detrusor sphincter dyssynergia, dysfunctional voiding, Fowler's syndrome, or primary bladder neck obstruction. Dysfunctional voiding is defined as a variable, intermittent, or fluctuating urinary flow rate in neurologically intact individuals due to involuntary spasmodic contractions of the urethral sphincter. Unlike detrusor sphincter dyssynergia, there is no underlying neurogenic disorder. Detrusor sphincter dyssynergia is caused by the contraction of the urethral sphincter and/or the periurethral striated muscles during bladder emptying. It is due to a disruption of the neural connections between the pontine micturition center and the caudal spinal cord. The specific diagnosis usually requires urodynamics with electromyography and/or video urodynamics. 

Epidemiology

Urinary retention is rare in women and much more common in men due to benign prostatic hyperplasia (BPH). There are an estimated 3 to 7 cases per 100,000 women yearly, and the female-to-male ratio is 1 to 13.[8][32] Compare this with men, where about one-third of all males over age 80 will develop acute urinary retention.[33] In older women, it may be asymptomatic.[2] Up to one-third of older women will have incomplete bladder emptying with increased post-void residual volumes.[34] It is generally accepted that female urinary retention is grossly underestimated and underdiagnosed.[35]  

Female urinary retention is also common after pelvic reconstructive surgeries and incontinence procedures. Preoperative voiding dysfunction and higher post-void residual volumes increased the risk for postoperative urinary retention.[36]

Urinary retention is relatively common after a normal vaginal delivery, with 14% of women found to develop urinary difficulty immediately postpartum, typically recognized as not voiding by 6 hours after delivery.[37] This increases to 20.6% in women who underwent an instrumented delivery, presumably from stretching the perineal muscles and possible denervation injury.[38][39] An episiotomy increases the chances of postpartum urinary retention.[39] Long-term voiding dysfunction may be present in up to 5% of postpartum patients with urinary retention, especially if their initial residual urine volumes are >1,000 mL.[40]

Postoperative urinary retention after a cesarean section with epidural anesthesia will occur in about 25% of patients. Hysterectomy is also associated with postoperative urinary retention, which can be reduced by nerve-sparing techniques or otherwise minimizing pelvic dissection, which appears to cause some degree of recoverable denervation.[41][42][43]

An unrecognized cystotomy as a complication of gynecologic surgery can also cause female urinary retention. The inadvertent cystotomy rate is reportedly about 1% to 3% after hysterectomy and 2% to 5% after retropubic sling surgery.[44][45][46][47][48] 

Pathophysiology

Voluntary urination requires close coordination between muscles of the pelvic floor, bladder, and urethra, as well as the nerves innervating them. Any disruption along the pathway can cause urinary retention. Even if this pathway coordinates and works properly, mechanical obstruction can cause urinary retention or interfere with bladder emptying. Obstruction can result from the urethral channel's narrowing, extrinsic compression, or significantly increased sphincter muscle tone. Neurological impairment can result in incomplete relaxation of the urinary sphincter, inefficient or deficient detrusor muscle contraction, spinal cord infarction/demyelination, epidural abscess, epidural metastasis, Guillain-Barre syndrome, neuropathy, stroke, or trauma to the spinal cord.[49][50]

Trauma to the lower genitourinary tract, pelvis, or urethra can also cause obstruction. Bladder outlet obstruction in women may also result from constipation, pelvic organ prolapse, pelvic masses, diverticular stones, hematomas, or kidney stones. A urinary tract infection can cause swelling or inflammation of the urethral mucosa resulting in a restricted lumen and subsequent urinary retention.[49][50][51][52]

An unrecognized cystotomy during gynecologic surgery can initially appear as voiding dysfunction. Often, patients will present with postoperative urinary retention or only void in small amounts. Symptoms may be non-specific such as abdominal fullness or hematuria, while delayed findings include ileus, peritonitis, genitourinary fistula, and sepsis. This is because the cystotomy opening acts as a one-way valve that lets urine out of the bladder into the low-pressure peritoneal but does not permit drainage back into the bladder. 

History and Physical

History and physical should focus on any history of urinary retention and symptoms involving the lower genitourinary tract. The symptoms can be discomfort with urination, hematuria, urethral discharge, foul-smelling urine, urgency, a feeling of incomplete emptying, or lower abdominal pain. Discomfort and lower abdominal pain are more likely to be associated with acute retention, while chronic retention may be asymptomatic or have more subtle symptoms such as a general feeling of a reduced urge to void, a sensation of incomplete emptying, a slow or intermittent urinary stream (unusual in females), stranguria, or hesitancy. Patients with urinary retention may also present with overflow incontinence which is present in <1% of women presenting lower urinary tract symptoms.[53] 

The patient should be asked about previous trauma, surgeries, or radiation to the pelvic and genitourinary area. A history of back pain, fever, IV drug use, or other neurological symptoms could point to possible causes of urinary retention. All medications, including OTC, prescription, and herbal, should be reviewed to determine whether side effects of these could be causing or exacerbating urinary retention.[54][55] Anticholinergics, antihistamines, and alpha-adrenergic agonists, such as common decongestants, can all tend to facilitate urinary retention.

The physical exam should include at least a lower abdominal palpation and a focused neurological examination. A rectal and pelvic exam should also be performed. On palpation of the lower abdomen, there may be some discomfort, or the bladder may be palpable. On the rectal exam, note any masses, fecal impaction, perineal sensation, and sphincter tone. The pelvic examination will detect atrophic vaginitis, tumors, urethral diverticula, prolapse, cystoceles, and rectoceles. A focused neurological exam may reveal deficits that may suggest a neurogenic etiology.[56][57][58] 

An attempt should be made to identify potentially curable causes of female urinary retention such as a retained or ill-fitting pessary, urinary tract infection, pelvic organ prolapse, urethral diverticula with a stone, fibroids, mesh erosion from prior pelvic surgery, etc.

A post-void residual urine volume should be obtained, preferably within 10 to 15 minutes of voiding, and a urinalysis should be done.

Evaluation

From a clinical standpoint, female urinary retention is divided into acute/postoperative and chronic.

Acute female urinary retention will typically present immediately after a precipitating event such as trauma, childbirth, botulinum toxin detrusor injections for overactivity, or surgery in a patient who previously had no urinary issues. Symptoms are usually significant lower abdominal pain, inability to void, a strong urge to urinate, and lower abdominal or suprapubic swelling.

Urodynamics testing with pressure-flow studies is not generally necessary or recommended for patients with acute urinary retention unless prolonged or intractable, but it may be helpful in cases of chronic retention or in patients with prior incontinence procedures to help identify an obstructed urethra. 

Numerous risk factors for acute and postoperative female urinary retention exist.[59][60][61][62] These include:

• Age over 50 years
• Administration of anticholinergic drugs during a surgical procedure
• Creation of a cystotomy possibly unrecognized during GYN surgery
• Diabetes
• Duration of anesthesia of more than 2 hours
• Higher IV fluid administration while under an anesthetic (>750 mL)
• Hypertension
• Joint replacement surgery
• Neurological disease or injury
• Pharmacological effects (anticholinergic, alpha agonists, etc.)
• Pelvic trauma
• Preexisting voiding dysfunction or high post-void residual urine volumes
• Previous episodes of urinary retention
• Prior pelvic or incontinence surgery
• Regional anesthesia (23% vs. 17% with a general anesthetic)
• Surgery: radical hysterectomy - 20% rate of postop acute urinary retention
• Surgery: low anterior resection - 68% rate of postop acute urinary retention 

Chronic female urinary retention generally has milder but more varied symptoms such as dysfunctional voiding, slow or intermittent urinary stream, hesitancy, straining, or incontinence from overflow. There is usually no abdominal or suprapubic pain and typically no immediate precipitating event. Symptoms have usually been present for an extended time, or patients may even be asymptomatic, with the urinary retention discovered only incidentally. Interestingly, a sensation of incomplete bladder emptying is not a reliable indicator of a high post-void residual volume.[63] 

The American Urological Association has defined chronic urinary retention as "an elevated post-void residual (PVR) urine volume of greater than 300 mL that persisted for at least six months documented on two or more separate occasions."[3] The main risks for patients with chronic urinary retention are persistent bacteriuria, recurrent UTIs, permanent bladder muscle damage, nephrolithiasis, and renal damage. The risk for renal disease is increased in the presence of persistently elevated bladder storage pressure, although the majority of neurologically intact women with chronic urinary retention will have detrusor underactivity and low pressures.

Risk factors for high-risk chronic urinary retention include:[3] 

• Bladder stones
• Hydronephrosis
• Hydroureter
• Recurrent or symptomatic UTIs
• Renal failure (GFR of <60 mL/min)
• Urinary incontinence associated with perineal skin changes or sacral decubitus ulcers
• Urosepsis

A urinalysis and culture are necessary for all female patients with urinary retention. This urine may have to be obtained via catheterization if the patient is unable to void voluntarily. The diagnosis of urinary retention is commonly made via obtaining a post-void residual urine volume. If the patient can void on her own, a bladder scan is utilized after the patient urinates to evaluate the amount of urine still in the bladder. More than 300 mL of urine in the bladder after voiding suggests urinary retention, although most clinicians use 200 mL as the maximal, acceptable post-void volume.[64][65][66] 

If the patient is unable to urinate, catheter placement may be necessary. If more than 400 mL of urine passes after catheterization in the first 15 minutes, this suggests urinary retention, and the catheter should remain in place unless the patient is willing and able to perform clean intermittent self-catheterization at regular intervals. Between volumes of 200 mL and 400 mL, the catheter may be removed immediately or left in place, depending on the clinical scenario. Under 200 mL, the catheter can generally be removed, and urinary retention is unlikely.[33][67][68]

Urodynamic testing is extremely helpful in differentiating detrusor underactivity from bladder outlet obstruction in women with chronic, unexplained urinary retention. With detrusor underactivity, detrusor pressure will be reduced or possibly even absent.[69] Urinary flow may be absent, intermittent, low, or possibly even normal.[69] Valsalva-assisted voiding (from straining and increased abdominal pressure) will typically cause an intermittent urinary flow and can be identified with urodynamics findings of an increased flow coinciding with an increase in abdominal pressure.

Bladder outlet obstruction in women is far less common than in men. Typically, this disorder demonstrates elevated detrusor pressure with either prolonged voiding time and/or a reduced urinary flow rate.[70][71][72] Video-urodynamics (pressure flow studies with fluoroscopy) is the current standard for diagnosing bladder outlet obstruction in women.[73] 

Pressure-flow studies should be evaluated cautiously as women typically have much lower normal voluntary voiding pressures than men, and the correlation between urinary retention severity and pressure-flow results is somewhat inconsistent.[74][73] Additional findings might include detrusor sphincter dyssynergia (a neurological disorder), non-relaxation of the urethral sphincter (as in Fowler's syndrome), or primary bladder neck obstruction. Video urodynamics can be very helpful in these more complex cases.[75][76] Patients who demonstrate sustained high detrusor storage pressure, especially with decreased bladder compliance or uncorrected stage 3 or 4 pelvic organ prolapse, are at increased risk of renal damage and should be monitored by renal ultrasonography and serum creatinine/GFR.

Cystoscopy can sometimes help detect anatomical disorders that may be contributing to urinary retention, such as strictures, masses, stones, or urethral erosions from surgical material used in prior pelvic surgeries.

Evaluation Summary:

• Acute urinary retention usually immediately follows a precipitating event such as surgery, botulinum toxin detrusor injections, injury, or childbirth.

• Immediate symptoms of suprapubic pain, inability to void, urgency, and incomplete bladder emptying are typical of acute retention.

• Retention is more likely after regional anesthetic blocks, older patients, diabetics, use of anticholinergics, and a history of prior pelvic surgeries.

• Post-void residual urine volumes will be >200 mL in patients with urinary retention.

• Postoperatively, patients should be closely monitored for bladder function and residual.

• Postoperative patients with residuals over 400 mL should be given an opportunity to void and catheterized if they fail.

• Immediate treatment is urethral catheterization, either with a Foley or intermittent self-catheterization.

• All patients with acute postoperative urinary retention should have their catheter irrigated. An inability to extract the injected fluid suggests a possible unrecognized cystotomy, and a cystogram should be performed.

• Continuous Foley drainage is suggested for volumes >1,500 mL, at least for a short time.

• If the urinary voiding disorder lasts >6 months, it is chronic retention.

• Urodynamics and video urodynamics are not necessary for acute retention but may be helpful in chronic patients.

• Cystoscopy can be helpful in chronic retention to identify obstructive causes that are potentially treatable.

• Patients with prior pelvic surgeries can develop pelvic organ prolapse or mesh erosions.

Treatment / Management

The initial management of a patient diagnosed with urinary retention is usually a urethral Foley catheter. The amount drained immediately should be recorded. Patients with more than 1,500 mL drained immediately from the bladder after catheter insertion are at risk for postobstructive diuresis.[77] Those with pre-existing renal failure (azotemia), bilateral hydronephrosis, or congestive heart failure are at an even higher risk of developing the disorder.

Postobstructive diuresis is a pathological condition of uncontrolled salt and water excretion. It is defined as more than 200 mL of urinary output per hour for at least 2 hours or more than 3,000 mL of urine over 24 hours.[77] Urinary output and serum electrolytes should be monitored for patients at risk. In severe cases or where patients cannot drink freely, intravenous fluids of normal saline at no more than 75% of the prior hour's urinary output should be administered, and serum electrolytes should be checked regularly.[77] Urinary specific gravity can be used as a simple marker to monitor the disorder's progress. A urine specific gravity of 1.010 would be iso-osmolar to normal serum and generally indicates the resolution of the postobstructive diuresis if it reaches 1.020 or more.[77] The process usually resolves in most cases in 24 hours. (See our companion reference StatPearls article on Postobstructive Diuresis.)[77]

In patients who are totally unable to void or have very large residuals (1,500 mL or more), a Foley catheter is preferred initially for monitoring due to possible postobstructive diuresis as well as therapeutic bladder decompression and recovery. If, for any reason, a urethral catheter cannot be inserted, a suprapubic tube can be placed instead. 

Bladder overdistension injury will occur if an overdistended bladder (defined as 120% or more of normal capacity or generally more than 600 mL) is maintained for 24 hours or longer.[78][79] Bladder wall ischemia can begin in as little as 30 minutes after the onset of detrusor overdistension. The ischemia results from stretched and narrowed blood vessels which reduce blood flow along with the markedly increased intravesical pressure. Smooth muscle contractility is further reduced due to direct detrusor muscle fiber injury and increased intracellular calcium.[80] The process is largely reversed after Foley catheter placement, but reperfusion can release oxidative free radicals and inflammatory chemicals such as tumor necrosis factor-alpha, which can cause further direct bladder tissue injury.[79][81] The larger the volume and the longer the urinary retention is unrecognized, the greater the potential for permanent detrusor muscle deterioration into acontractile fibrous tissue.[82] 

Acute urinary retention is best managed with a short-term Foley catheter or clean intermittent patient self-catheterization until the resolution of the disorder. An initial Foley catheter is usually preferred if residual volumes of >1,000 mL are encountered. This can be converted to a self-catheterization program if the patient is willing and able to do so. A benefit of self-catheterization is that when normal bladder function returns, the post-void residual volumes will decrease, and it will become obvious that the catheterizations are no longer needed. For this reason, it is suggested that the patient measure and record the post-void residual amount occasionally, such as once a day. Another advantage is that if the patient ever feels a return of symptoms, she can perform a self-catheterization and avoid a visit to the emergency department. 

The risk of a significant decrease in renal function or permanent bladder damage is minimal in acute urinary retention if identified and treated promptly. A Foley catheter, suprapubic tube, or clean intermittent self-catheterization will be necessary for female patients with acute urinary retention not due to a mechanical obstruction who remain unable to void adequately on their own. A full recovery is unlikely if it has not occurred by six to eight months after the original acute event, which now becomes chronic urinary retention.

Intermittent self-catheterization is preferred over indwelling catheters or suprapubic tubes whenever possible, except in cases of very large initial bladder volumes of 1,500 mL or more where an initial period of continuous Foley catheterization is suggested.[83][84] Patients with acute retention following a major abdominal or pelvic trauma with a possible urethral injury should initially receive a suprapubic tube.[85][86]

Patients suspected of a possible unrecognized surgical cystotomy (essentially all female patients with urinary retention immediately after any major pelvic surgery) can be checked by simple irrigation of the bladder through a Foley catheter with 100 mL of sterile saline. In patients with an unrecognized cystotomy, the fluid can be instilled but cannot be withdrawn. In such cases, an immediate x-ray cystogram should be done. Small extraperitoneal bladder perforations can often be managed conservatively with just a Foley catheter, but if the leak is particularly large or intraperitoneal, an immediate surgical repair is required.[87][88]

Clean Intermittent Self-Catheterization

Patients who are candidates for clean intermittent self-catheterization need to have the manual dexterity and strength to perform the procedure, as well as the mental ability to understand the procedure and the willingness to do so on an ongoing, regular basis. For many patients, an initial schedule might be four times a day: morning, after lunch, after dinner, and at bedtime. Additional catheterizations are permitted depending on the volumes obtained and patient sensation. Some patients may need to perform self-catheterization six times a day and possibly once at night as well.

The patient should always void first, if able. The timing of the catheterizations should be adjusted to maintain a catheterized urinary volume of no more than 500 mL. When the catheterizations are consistently less than 200 mL, consideration can be given to performing them less often or stopping the procedure altogether.

Learning how to perform self-catheterization can be challenging for many women. They may not be familiar with the anatomy, or their body habitus may make it difficult. The use of a mirror is suggested and can be helpful for many women who otherwise would have difficulty doing the procedure. A flashlight is also helpful. Patients should wash their hands or use gloves (non-sterile) before performing self-catheterization. Pre-lubricated, non-touch catheters are commercially available. Washing the genital area and using an antiseptic wipe just before catheterizing is recommended to minimize urinary tract infections. Prophylactic antibiotics are not generally used except in exceptional cases.

An experienced female nurse is suggested for this training to minimize patient anxiety and discomfort. This should not be rushed, and patients should be given ample opportunity to learn and practice the technique if they are capable and interested. The importance of maintaining a regular schedule of bladder emptying should be emphasized to avoid urological complications. Many educational aids and videos are available online and from various healthcare organizations and societies, including the Society of Urologic Nurses and Associates (SUNA) and the American Urological Association (AUA).

Voiding Trial

At some point, patients with acute retention requiring a Foley will be ready for a voiding trial. (This is not necessary for patients doing self-catheterization as their residual urine volumes will indicate when it's safe to discontinue the practice.) For most neurologically intact patients, this can be done within a few days to a few weeks after the initial episode of urinary retention. If the original bladder volume drained was over 1,500 to 2,000 mL, a longer period is recommended to allow the bladder muscle more time to recover, such as two to four weeks.

For an active voiding trial, such as can be done in an office or clinic, the bladder is filled with 300 mL of sterile saline or to maximum tolerable capacity. The catheter is then removed, and the patient is allowed to void. Success is generally defined as a post-void residual volume of 100 mL or less, although less than 200 mL may be acceptable in some cases. Success may also be defined as a post-void residual volume of no more than one-third of the amount instilled.

A spontaneous voiding trial may be easier for hospitalized patients who can just have their catheters removed early in the morning (such as at 5 or 6 AM before the usual change of nursing shifts) and then be taken to the bathroom to try voiding after 4 hours. A bladder scan should be done for a post-void residual when the patient voids, but the scan should be done even if the patient is unable to urinate in order to avoid bladder overdistension. The patient is then given another opportunity to void every 2 hours until they are successful or their residual volumes approach 500 mL. Success is again defined as post-void residual urine of 100 mL or less. It may also be defined as a post-void residual of only one-third or less of the total bladder volume.

A post-void residual of over 200 mL is regarded as abnormal, while a reading of 100 to 200 mL is considered equivocal.[65][89] Whether a urinary catheter remains in place is determined by the clinical scenario (acute or chronic, high risk or low) and the patient's risk status, preferences, home situation, comorbidities, and abilities.

Chronic urinary retention is treated initially the same as acute urinary retention: either with a urethral Foley catheter, suprapubic tube or by clean intermittent self-catheterization. AUA Guidelines also recommend a renal function test (serum creatinine) and renal ultrasound as initial baseline tests in newly diagnosed patients with chronic urinary retention.[3] An initial period with a continuously draining catheter is suggested in patients with significant medical comorbidities, UTI, sepsis, large urinary volumes drained immediately after catheterization (typically >1,500 mL), or who are otherwise at high risk for postobstructive diuresis or other complications. This can be converted into a self-catheterization program as soon as practicable in appropriate patients.

Long-term intermittent self-catheterization is a reasonable treatment option for many women with chronic urinary retention, as most will demonstrate detrusor underactivity and low bladder storage pressures, which minimizes the risk of renal failure.[90] Those patients with complete urinary retention will require a catheter in some form for bladder drainage.

Patients with acute or chronic retention associated with a urinary tract infection, sepsis, hemodynamic instability, a high likelihood of severe postobstructive diuresis, acute myelopathy, or acute renal failure should generally be admitted.[33][91]

Conservative treatment measures have had some limited success in treating female urinary retention. Physical therapy with biofeedback has shown benefits in some patients with prolapse, rectoceles, cystoceles, and dysfunctional voiding.[92] 

Those patients with specific obstructive disorders usually benefit from customized therapy.

• Patients with pelvic organ prolapse clearly benefit from treatment of the prolapse.

• Using a pessary to correct stage 3 or 4 pelvic organ prolapse resulted in improved post-void residual volumes in 75% of such patients with urinary retention.[93]

• Surgical prolapse repair resulted in normal post-void residual volumes of 89%.[94]

• Urethral dilations are not generally recommended in female patients with urinary retention, especially not after synthetic sling surgery, due to the risk of mesh erosions, but may be of use in selected cases with known urethral strictures.[95][96][97]

• Most urinary retention patients with urethral erosions from prior pelvic incontinence surgery will see a relief of their voiding problem by the removal of the transvaginal sling and urethral reconstruction.[98][99]

• In carefully selected female patients with primary bladder neck obstruction, about 85% saw relief of their urinary retention from surgical transurethral bladder neck incision.[100][101] However, since this procedure can cause permanent incontinence, its use in female patients is not yet generally recommended.

• Botulinum toxin injections have been used successfully in men with primary bladder neck obstruction, but there is inadequate data available about its use in female patients with chronic urinary retention.

• Bethanechol is a cholinergic agonist that can increase detrusor muscle tone. However, it has not demonstrated any significant benefit, either alone or with prostaglandin E2, in treating non-obstructive female urinary retention even with detrusor underactivity and is therefore not recommended.[102][103][104] Bethanechol also has significant potential side effects. 

Alpha-adrenergic blocker medications such as tamsulosin generally appear to help, but many studies regarding its use are small, lack a control group, are short-term, and results are somewhat inconsistent. Overall, alpha-adrenergic blocker medications are generally recommended as most available studies show the benefit of this therapy in female patients with urinary retention. The medication is well tolerated, and no other simple, more effective alternative treatment exists.[105][106][107][108][109][110] Tamsulosin therapy pre-operatively has also been shown to help reduce postoperative female urinary retention.[91][111] 

Sacral neuromodulation is a minimally invasive treatment that utilizes an implantable device to provide gentle electrical stimulation of the S3 nerve root to modulate bladder function. While particularly effective for many patients with intractable overactive bladder disorders, sacral neuromodulation also offers an overall 70% success rate in treating non-obstructive female urinary retention.[27][35][112][113][114][115] 

The mechanism of action is not well understood but is thought to be through inhibition of the guarding reflex, which normally prevents accidental urinary leakage by activating somatic efferent fibers to contract the external urinary sphincter. This is initiated by afferent signals to Onuf's nucleus during periods of increased pressure, such as during a cough.[113] It is effective in patients with detrusor underactivity and can be used in older patients, although it is more effective in younger women.[8][115]

Many ladies are unhappy about the generally accepted treatments of alpha-blockers, urethral dilation, intermittent catheterization, permanent catheterization, pessary placement, surgery, Botulinum toxin urethral injections, pelvic floor exercises, and physical therapy due to inconvenience, discomfort, or lack of efficacy which makes sacral neuromodulation a viable alternative for many.[116] Sacral neuromodulation is a reasonable and effective treatment for urinary retention due to detrusor sphincter dyssynergia and Fowler's syndrome.[117] 

Sacral neuromodulation is relatively costly, and long-term efficacy is uncertain. A surgical procedure is needed for placement. Battery life is limited, and older models will require periodic implant replacement or at least periodic recharging for newer, rechargeable units.[118] The tined leads can migrate or break, the device may need periodic reprogramming or cease functioning, and the entire device may break down over time.[8] The reported overall removal rate for sacral neuromodulation after implantation is 10% to 20%.[114][119][120][121] (See our companion article on Sacral Neuromodulation.)[113]

Fowler syndrome may be best treated by sacral neuromodulation as it has been shown to increase detrusor contractility without increasing urethral activity.[116] Suprapubic tubes are uncomfortable in younger ladies, and intermittent self-catheterization is often painful in this disorder due to excessive urethral muscle pressure. In one study of 26 women with Fowler's syndrome and urinary retention treated with sacral neuromodulation for 72 months, an impressive 77% could void independently without needing catheterization.[112] 

Sacral neuromodulation is the recommended treatment for Fowler's syndrome, as surgeries and medications are not usually effective, and there is evidence of restoration of normal voiding in many patients.[112] Voltages of <3 volts have been found to provide better results.[122] Botulinum toxin injection into the urethral sphincter has not yet been adequately tested in patients with this disorder, but 37% to 43% of patients in small test groups indicated improvement.[29][123][124][125] Ultimately, patients who fail these measures may require a continent urinary diversion for relief.[29]

Percutaneous tibial nerve stimulation is similar to sacral neuromodulation because the intention is to activate the S3 nerve route. This is achieved indirectly by stimulating the tibial nerve at the ankle. This avoids surgical implantation of tined leads or stimulator battery packs but is generally less effective. Patients receive tibial nerve stimulation treatments weekly in the office or clinic for 12 weeks.

There is limited data on the use of percutaneous tibial nerve stimulation for female urinary retention, although a recent systematic analysis showed a moderate success rate of 25% to 41%, with more than half the patients indicating subjective improvement.[126] Overall, percutaneous tibial nerve therapy is considered roughly half as effective as direct S3 root stimulation with sacral neuromodulation. The FDA has approved a new implantable tibial nerve stimulator, and another is currently under investigation. There is no data on the efficacy of these implantable devices for female urinary retention as they were approved for detrusor overactivity.

Treatment Summary:

• Initial treatment for acute or chronic urinary retention is the same; Foley catheter, suprapubic tube, or self-catheterization depending on patient capability and willingness.

• Short-term continuous catheterization is recommended for high-risk patients and those with larger bladder residual volumes (>1,500 mL).

• Intermittent self-catheterization is recommended whenever possible.

• Persistent post-void residuals of <200 mL generally indicate resolution of urinary retention.

• Acute retention for six months or more is treated as chronic urinary retention.

• Retention caused by specific obstructive disorders should have those problems corrected.

• Pelvic organ prolapse can be treated with a pessary or surgery.

• Urethral strictures can be treated with dilation, which is otherwise not recommended, particularly not after sling surgery due to the high risk of urethral erosions.

• Botulinum toxin and transurethral incision or resection may be helpful in selected patients, but there is a worrisome risk of permanent incontinence.

• Bethanechol is not recommended due to its low efficacy and high side effect profile.

• Alpha-adrenergic blockers such as tamsulosin are generally recommended as the preponderance of the available evidence suggests a benefit.[111]

• Sacral neuromodulation and percutaneous tibial nerve stimulation are recommended options in non-obstructive chronic female urinary retention.

Differential Diagnosis

Causes of urinary retention and conditions that may mimic it include but are not limited to obstruction at any point along the lower genitourinary tract or nerve dysfunction. A blockage may result from pelvic masses, constipation, urethral stone, infection-causing urethral inflammation, stenosis, strictures, urethral diverticulum, and neurological dysfunction.[127]

Prognosis

The prognosis of urinary retention is fair if recognized early and treated promptly. Acute urinary retention, such as immediately after major surgery, will usually resolve by itself within a few days to weeks. Obstructive causes may not resolve without surgical relief of the obstruction. Immediate issues of bladder overdistension and upper tract deterioration can be managed by either continuous or intermittent catheterization. Resolution of chronic urinary retention is more problematic and depends on the underlying cause, comorbidities, and availability of therapies such as sacral neuromodulation.

In a double-blinded, prospective study of 600 patients, predictive nursing and early drinking water therapy have been shown to reduce the incidence of postpartum urinary retention.[128]

Sacral neuromodulation and percutaneous tibial nerve stimulation are still probably underutilized therapies for chronic female urinary retention. Implantable tibial nerve stimulators may prove to be an important future therapeutic option but require further testing to demonstrate efficacy for female urinary retention.

Intraurethral valve pumps, which are short silicone urethral catheters that contain an internal valve and pump mechanism that is activated by the patient using a remote control, are FDA approved, available, and reasonably effective in selected cases but tend to be costly, uncomfortable, and prone to leaking although future generations of these devices may overcome these limitations.[129][130][131] They have been used mostly outside the US for 20 years and are tolerable for about half of the patients who have tried them.[130] 

Follow-up

The American Urological Association Guidelines recommend a yearly follow-up examination including a history and physical, and post-void residual determinations are considered minimal. High-risk patients, including those previously diagnosed with renal failure, nephrolithiasis, or hydronephrosis, should also have yearly kidney function studies (creatinine) and renal ultrasonography.[3]

Complications

Complications of urinary retention include but are not limited to acute kidney injury, bladder injury, and urinary tract infections. There are also complications with catheterization, both suprapubic and urethral, such as urinary tract infections, urethral erosion, bladder spasms, bladder stones, reflux nephropathy, cellulitis at the cystostomy site, nephrolithiasis, renal parenchyma damage, renal deterioration, etc.[5][33][132][133] Urethral catheterization can result in a direct urethral injury during insertion. Suprapubic catheterization can result in trauma to the bladder/colon and develop leaks or an overlying skin infection.[91][134]

Another important complication seen in clinical practice is post-obstructive diuresis. This phenomenon is characterized by the excretion of large amounts of salt and water immediately after the urinary is relieved by a catheter. It may be a normal physiological response to the obstruction, but physicians should keep a close eye on patients as some continue to excrete large amounts of urine and are at risk for dehydration and metabolic abnormalities.[135] Risk factors include patients with azotemia, fluid retention, and those with particularly high bladder volumes, typically 1,500 or more.[77]

Transurethral resection or incisions have demonstrated some efficacy, but there is a considerable risk of permanent urinary incontinence. Botulinum toxin urethral injections are a promising treatment method, but there is no standardized methodology or dosage at this point and only limited data on efficacy. Sacran neuromodulation has proven efficacy but requires surgical implantation and routine follow-up and has a high re-operation and explanation rate.

Postoperative and Rehabilitation Care

A standardized protocol for monitoring female patients after childbirth, prolonged anesthesia, and major pelvic surgeries is highly recommended as it can help identify individuals with acute urinary retention before there is extensive detrusor damage. A bladder ultrasound to check residual volume at 4 to 6 hours post-op has been suggested as a minimal, reasonable protocol. With the wide availability of bladder ultrasound equipment in recovery rooms and hospitals, a bladder residual can easily be checked, especially in higher-risk individuals. 

Rehab centers should emphasize the teaching and reinforcement of intermittent self-catheterization techniques for female patients with urinary retention. They should also be able to customize a schedule based on each patient's individual clinical situation, bladder capacity, comorbidities, capabilities, and urine production.

Deterrence and Patient Education

Urinary retention is the inability to pass urine and can be acute or chronic. Although uncommon in women compared to men, it can still lead to significant issues of permanent bladder damage, renal deterioration, stones, infections, and Foley catheter dependency when not recognized and treated early. Patients should speak with their doctors if they have any issues with urination, such as dribbling of urine intermittently, a foul smell of urine, a feeling of incomplete emptying, hesitancy, etc. Checking a post-void residual urine volume with either a straight catheterization or ultrasound can quickly establish or eliminate a diagnosis of urinary retention.

Pearls and Other Issues

• Acute and chronic female urinary retention are initially treated the same.

• Always convert to self-catheterization, if possible, until the patient is voiding normally.

• Use an experienced female nurse for self-catheterization patient teaching.

• Urodynamics is not generally very helpful in evaluating patients with acute urinary retention.

• Tamsulosin is worth trying as there is evidence of some efficacy; it is well tolerated and may provide a psychological (placebo effect) benefit.[111]

• All younger ladies with unexplained urinary retention should be suspected of Fowler syndrome.

• All postoperative patients with urinary retention should have their catheters irrigated. A cystogram should be performed if no irrigation can be aspirated from the bladder.

• Sacral neuromodulation and/or posterior tibial nerve stimulation are reasonable treatment options for most women with chronic urinary retention.

• Patients who demonstrate very little detrusor activity and lack bladder sensation tended to have the worst outcomes after aggressive management (transurethral surgery, botulinum toxin urethral injections) of their urinary retention.[136]

• After significant pelvic trauma with a suspected urethral injury, a suprapubic tube should be placed.

• In rare cases, an imperforate hymen can cause an obstructive type of urinary retention in pubescent girls.[137]

Enhancing Healthcare Team Outcomes

Diagnosis and treatment of urinary retention require an interprofessional team effort. Primary care physicians, emergency department physicians, and hospitalists should be able to recognize the early signs and symptoms of urinary retention. Nurses should monitor the urine output in hospitalized patients and report to physicians if they notice a decrease or complete absence of urine output or voiding. Protocols for post-partum voiding have demonstrated usefulness in minimizing urinary complications such as acute retention but require close cooperation between OB-GYN, urology, family practice, and nursing. Urology should be involved in unusual, difficult, or refractory cases.

Nursing must monitor these patients post-procedure and report back to the surgeon or attending if there are any significant status changes. Pharmacists also have a role in recognizing the medications which can cause urinary retention and coordinating efforts with the prescribing clinician.[2][33][138] Unfortunately, despite optimal treatment, the recurrence of urinary retention is relatively common. Open communication between all team members is necessary for optimal outcomes, including keeping accurate and updated patient records so that all interprofessional team members can access the same updated patient information. [Level 5]