What are the diagnosis and treatment options for a patient with urinary retention, considering potential causes such as benign prostatic hyperplasia (BPH) in men and pelvic organ prolapse in women?

Urinary Retention: Diagnosis and Treatment

Immediate Diagnosis and Management

For acute urinary retention, perform immediate bladder decompression via urethral catheterization and simultaneously start a non-titratable alpha blocker (tamsulosin 0.4 mg or alfuzosin 10 mg once daily) at the time of catheter insertion. 1

Diagnostic Confirmation

• Confirm urinary retention through bladder scanning or straight catheterization to quantify residual volume 1
• There is no universal consensus on post-void residual (PVR) thresholds for acute retention, but chronic urinary retention is defined as PVR >300 mL measured on two separate occasions persisting for at least six months 2
• If blood is present at the urethral meatus after pelvic trauma, perform retrograde urethrography before attempting catheterization to rule out urethral injury 1

Etiologic Evaluation

• Perform urethrocystoscopy or retrograde urethrogram if urethral stricture is suspected 1
• Evaluate for constipation, particularly in elderly patients, as this is a common reversible cause 1
• In patients with neurological conditions, urodynamic studies may be necessary to assess detrusor function 1
• Consider medication review for anticholinergic agents and alpha-adrenergic agonists that can precipitate retention 3

Pharmacologic Management for BPH-Related Retention

Alpha Blocker Therapy Prior to Catheter Removal

Administer a non-titratable alpha blocker (tamsulosin or alfuzosin) for at least 3 days before attempting catheter removal to maximize success rates of voiding trials. 4, 1

• Alfuzosin achieves 60% success versus 39% with placebo in trial without catheter (TWOC) 1
• Tamsulosin achieves 47% success versus 29% with placebo in TWOC 1
• Alpha blockers (alfuzosin, doxazosin, tamsulosin, terazosin) are appropriate treatment options for lower urinary tract symptoms secondary to BPH, with all four agents having equal clinical effectiveness 4
• Avoid using doxazosin or terazosin as first-line agents in acute retention, as these require titration and doxazosin has been associated with increased congestive heart failure in men with cardiac risk factors 1

Contraindications to Alpha Blockers

• Do not use alpha blockers in patients with prior history of alpha-blocker side effects 4
• Exercise caution in patients with unstable medical comorbidities including orthostatic hypotension or cerebrovascular disease 4, 1
• Tamsulosin may have a lower probability of orthostatic hypotension compared to other alpha blockers, making it preferable in high-risk patients 1

5-Alpha Reductase Inhibitors

For patients with prostatic enlargement (>30cc), add a 5-alpha reductase inhibitor (finasteride 5 mg or dutasteride) to alpha blocker therapy to reduce long-term risk of recurrent retention. 1, 5

• Finasteride is indicated to improve symptoms, reduce risk of acute urinary retention, and reduce need for surgery including TURP in men with enlarged prostate 5
• Finasteride reduces acute urinary retention risk by 57% and surgery risk by 55% 1
• Combination therapy with alpha blockers and 5-alpha reductase inhibitors reduces progression risk by 67%, acute urinary retention by 79%, and need for surgery by 67% compared to placebo 1
• The magnitude of symptom response is greater in patients with enlarged prostate at baseline 5

Trial Without Catheter (TWOC)

Timing and Technique

• Keep the catheter in place for at least 3 days of alpha blocker therapy before attempting removal 1
• There is no evidence that catheterization longer than 72 hours improves outcomes, and prolonged catheterization increases infection risk 1
• A voiding trial is more likely successful if underlying retention was precipitated by temporary factors (e.g., anesthesia or alpha-adrenergic sympathomimetic cold medications) 4, 1

Post-TWOC Counseling

• Counsel patients that they remain at increased risk for recurrent urinary retention even after successful catheter removal 1
• For patients with underlying BPH or persistent lower urinary tract symptoms, consider indefinite alpha blocker therapy 1

Surgical Management

Surgery is recommended for patients with refractory retention who have failed at least one attempt at catheter removal. 4, 1

Indications for Surgery

• Refractory urinary retention after failed voiding trial 4, 1
• Renal insufficiency clearly due to BPH 4, 1
• Recurrent UTIs clearly due to BPH and refractory to other therapies 4, 1
• Recurrent gross hematuria clearly due to BPH and refractory to other therapies 4, 1
• Bladder stones clearly due to BPH and refractory to other therapies 4, 1

Surgical Options

• Transurethral resection of the prostate (TURP) remains the benchmark surgical treatment for BPH-related urinary retention 1
• Selection of energy source and instrumentation should be based on surgeon's experience, patient's prostatic anatomy, and medical comorbidities 1
• Avoid delaying surgical intervention in patients with refractory retention, as this can lead to bladder decompensation and chronic retention 1

Non-Surgical Candidates

• For patients who are not surgical candidates, treatment with intermittent catheterization, an indwelling catheter, or stent is recommended 4
• Prostatic stents should only be considered in high-risk patients who cannot undergo other treatments, as they are associated with significant complications including encrustation, infection, and chronic pain 1

Catheterization Strategies

Acute Management

• Immediate bladder decompression via urethral catheterization is the first-line approach 1, 3
• If urethral catheterization fails or urethral injury is confirmed, place a suprapubic catheter for drainage 1
• Silver alloy-coated urinary catheters should be considered to reduce urinary tract infection risk 1

Chronic Management

• Intermittent catheterization is generally recommended for initial management rather than indwelling catheters 1
• For chronic intermittent catheterization, perform catheterization 4-6 times daily at regular intervals (approximately every 4-6 hours) to maintain bladder volumes below 400-500 mL 1
• Hydrophilic or low-friction catheters show benefit in reducing complications for chronic use 1
• Remove indwelling catheters as soon as medically possible, ideally within 24-48 hours, to minimize infection risk 1

Long-Term Catheterization

• Chronic indwelling urethral or suprapubic catheters should only be recommended when therapies are contraindicated, ineffective, or no longer desired by the patient 1
• Suprapubic tubes are preferred over urethral catheters due to reduced likelihood of urethral damage 1

Special Considerations

Urethral Stricture

• For urgent management of urethral stricture, options include urethral dilation, direct visual internal urethrotomy, or immediate suprapubic cystostomy 1
• Consider self-catheterization after direct visual internal urethrotomy to maintain temporary urethral patency in patients who are not candidates for urethroplasty 1
• Avoid repeated intermittent catheterization for pelvic fracture urethral injury, as this increases patient morbidity and delays definitive reconstruction 1

Neurogenic Bladder

• For patients with neurogenic bladder, clean intermittent self-catheterization is the preferred long-term management strategy 1
• Patients should be monitored in conjunction with neurology and urology subspecialists 2

Antibiotic Use

• Urinary retention alone does not warrant antibiotics without confirmed infection 1
• Antibiotics should only be prescribed if systemic signs of infection are present or after culture confirms infection 1
• For catheter-associated UTIs, appropriate choices include fosfomycin, nitrofurantoin, fluoroquinolones, or cotrimoxazole 1

Critical Pitfalls to Avoid

• Never attempt blind catheter passage prior to retrograde urethrogram in cases of suspected urethral injury, as it may exacerbate the injury 1
• Do not assume alpha blocker therapy alone will manage concomitant hypertension; hypertension may require separate management 1
• Avoid using prazosin or phenoxybenzamine, as data are insufficient to support their use for BPH-related symptoms 4
• Prolonged use of indwelling catheters increases the risk of urinary tract infections and should be avoided 1
• Catheter-associated urinary tract infections account for nearly 40% of all nosocomial infections 1