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Acute Urinary Retention

Acute urinary retention (AUR) is a urological emergency characterized by a sudden, painful inability to void. Immediate management is prompt and complete bladder decompression by catheterization.[1][2] The evidence supports rapid, complete emptying over gradual decompression — the longstanding practice of "clamping" the catheter has no supporting evidence and is not recommended.[3]

Part I: Definition, epidemiology, and etiology​

Definition and classification​

AUR is defined by the International Continence Society as a painful, palpable, or percussible bladder in a patient unable to pass urine.[4] It is distinguished from chronic urinary retention (CUR), which the AUA defines as PVR >300 mL on two separate occasions persisting for ≥6 months.[1]

  • Spontaneous AUR — no identifiable precipitant; worse prognosis and higher surgical rates (71% of cases in the Reten-World survey).[5]
  • Precipitated AUR — triggered by an identifiable event (anesthesia [28.5%], excessive alcohol [18.2%], medications, constipation, UTI); better prognosis with higher TWOC success rates.[5]

Epidemiology​

AUR predominantly affects men, with an incidence of 2.2–6.8 per 1,000 men per year, rising sharply after age 70.[2] Mortality within the year following an AUR episode is significantly higher than in the general population, particularly in younger patients — AUR is a marker of systemic disease burden, not merely a local problem.[2] In women, urinary retention is far less common (prevalence ~1,532 per 100,000 female Medicare beneficiaries), with neurologic conditions, UTI, and pelvic organ prolapse as the strongest associated risk factors.[6]

Etiology​

CategoryCommon causes
Obstructive (most common)BPH (53% of all AUR), urethral stricture, bladder-neck contracture, prostate cancer, phimosis, meatal stenosis, blood clots (clot retention), bladder stones
Obstructive — female-specificPelvic organ prolapse (cystocele, uterine prolapse), uterine leiomyomas (posterior / fundal with retroverted uterus), pelvic masses, urethral diverticulum
Infectious / inflammatoryAcute bacterial prostatitis, cystitis, urethritis, vulvovaginitis, herpes simplex (sacral radiculitis), periurethral abscess
PharmacologicAnticholinergics, alpha-adrenergic agonists (decongestants), opioids, benzodiazepines, NSAIDs, calcium-channel blockers, antihistamines, tricyclic antidepressants
NeurologicSpinal cord injury, cauda equina syndrome, multiple sclerosis, diabetic neuropathy, stroke, Parkinson's disease, Fowler's syndrome (young women)
PostoperativeRegional / general anesthesia, pelvic surgery, prolonged immobilization, pain / opioid use
[1][2][4][7][8][9][10]

Fowler's syndrome deserves special mention as a cause of AUR in young women (typically ages 20–30), characterized by impaired urethral sphincter relaxation, large bladder capacity, reduced sensation, and detrusor underactivity. It is associated with polycystic ovary syndrome and is the only form of idiopathic female retention with a specific treatment — sacral neuromodulation (>70% therapeutic effectiveness).[10]

Part II: Initial evaluation​

Principle 1 — Rapid assessment before catheterization​

While catheterization should not be delayed, a focused assessment guides the approach:[1][7]

  • History — duration of inability to void, pain severity, prior voiding symptoms (LUTS), medication review (anticholinergics, opioids, alpha-agonists, herbal supplements), prior urologic history (strictures, BPH, prior catheterization), and neurologic symptoms (saddle anesthesia, lower-extremity weakness, bowel dysfunction — red flags for cauda equina syndrome).
  • Physical examination — suprapubic palpation / percussion (distended bladder), digital rectal examination (prostate size, tenderness suggesting prostatitis, rectal tone), focused neurologic exam (perineal sensation, anal sphincter tone, lower-extremity reflexes), and pelvic exam in women (prolapse, masses).
  • Bladder scanner — the RAND / UCLA expert panel (URECA algorithm) recommends bladder scanning as the preferred diagnostic tool over catheterization for confirming retention. Catheterization thresholds: ≥300 mL for symptomatic patients and ≥500 mL for asymptomatic patients.[13]

Principle 2 — Rule out urethral injury before catheterization​

In the trauma setting, urethral catheterization must be preceded by assessment for urethral injury. The ACS Best Practices Guidelines state:[14]

  • Abort the procedure if any resistance is encountered during catheter advancement or if urine is not obtained.
  • Consider retrograde urethrography (RUG) if urethral injury is suspected (blood at the meatus, perineal hematoma, high-riding prostate, pelvic fracture).
  • A straight-tip Foley catheter is preferred in trauma; coudé-tip catheters are not recommended in this setting.

Part III: Emergent bladder decompression — techniques​

Principle 3 — Urethral catheterization: first-line approach​

Urethral catheterization is the standard first-line intervention for AUR, performed in 87–90% of cases worldwide.[2][5]

Standard technique:

  • Sterile preparation and draping; generous application of 2% lidocaine gel into the urethra (allow 5–10 minutes for anesthetic effect).
  • Catheter size — 14–16 Fr for adults; larger (18–20 Fr) for suspected clot retention to facilitate irrigation.
  • Advance the catheter to the hub (in males) before inflating the balloon — premature inflation is a leading cause of iatrogenic urethral injury.[14]
  • Inflate the balloon only after urine is seen draining in the tubing.[14]
  • Secure the catheter to the thigh to prevent inadvertent traction / extraction.[14]

The coudé catheter. The coudé (curved-tip) catheter is designed to navigate the upward angulation at the prostatic urethra in men with BPH. Miller et al. demonstrated that implementing universal coudé catheter use for all male OR catheterizations reduced the traumatic catheterization rate from 3.0% to 0.2% (p<0.001).[15] The tip is oriented with the curve facing anteriorly (toward the ceiling in supine patients) to glide over the prostatic obstruction.

Principle 4 — Managing difficult urethral catheterization​

When standard catheterization fails, a stepwise escalation algorithm should be followed rather than repeated blind attempts (which cause urethral trauma, false passages, and edema):[16][17]

Step 1 — Optimize the initial attempt:

  • Ensure adequate lubrication and anesthesia (lidocaine gel, 5–10 min dwell time).
  • Try a coudé-tip catheter if a straight catheter fails.
  • Stretch the penis to its full length and hold it perpendicular to the body to straighten the urethra.

Step 2 — Guidewire-assisted catheterization:

  • A hydrophilic guidewire is passed through the urethra into the bladder under tactile guidance.
  • A Council-tip catheter (with an end-hole) is advanced over the wire into the bladder.
  • The Urethral Catheterisation Device (UCD) integrates a hydrophilic nitinol guidewire into a 16 Fr silicone catheter for this purpose.[18]

Step 3 — Flexible cystoscopy-assisted catheterization:

  • Bedside flexible cystoscopy allows direct visualization of the obstruction (stricture, false passage, bladder-neck contracture).
  • A guidewire is passed through the working channel under direct vision, and a catheter is placed over the wire.
  • Beaghler et al. achieved successful catheter placement in 52 of 54 patients (96%) using this technique, avoiding suprapubic catheterization in nearly all.[17]

Step 4 — Fluoroscopy-guided catheterization:

  • For cases where cystoscopy fails or is unavailable, Kim et al. demonstrated 100% technical and clinical success in 179 fluoroscopy-guided catheterizations, with only 2.2% complication rate.[19]

Step 5 — Suprapubic catheterization (see below).

Principle 5 — Suprapubic catheterization: when urethral access fails or is contraindicated​

Suprapubic catheter (SPC) placement is indicated when urethral catheterization fails, is contraindicated, or is not feasible:[20][21][22]

Indications:

  • Failed urethral catheterization after stepwise escalation.
  • Known urethral disruption (trauma) or complete urethral stricture.
  • Acute bacterial prostatitis (relative — to avoid urethral manipulation through an infected gland).[9]
  • Long-term catheterization anticipated (improved patient comfort, lower bacteriuria, easier sexual activity).[23][24]

Contraindications:

  • Non-distended or non-palpable bladder (most important — risk of bowel injury).
  • Bladder cancer (risk of tumor seeding along the tract).
  • Prior lower-abdominal / pelvic surgery (peritoneal adhesions overlying the bladder).
  • Anticoagulation / coagulopathy (relative).
  • Abdominal-wall sepsis.
  • Pregnancy.[20][24]

Technique — percutaneous (bedside):

  • Confirm bladder distension by palpation and ultrasound — Aguilera et al. demonstrated 100% success with real-time ultrasound-guided SPC placement in 17 ED patients with zero complications.[22]
  • Entry point: 3 cm above the pubic symphysis in the midline (or 1–2 cm off midline).
  • The trocar / needle is directed posteriorly and inferiorly toward the bladder dome.
  • Goyal et al. reported successful bedside trocar SPC placement in 72 consecutive patients with no complications, with average procedure time <5 minutes.[21]
  • Bowel-injury risk — 0–2.7%; the primary concern, particularly in patients with prior abdominal surgery or an inadequately distended bladder.[9]

Technique — open cystostomy:

  • Reserved for patients with prior pelvic surgery where peritoneal adhesions may overlie the bladder, making percutaneous access dangerous.
  • A small infraumbilical midline or transverse incision is made, the rectus muscles are separated, the peritoneum is displaced cephalad, and the bladder is opened between stay sutures.
  • A Malecot or Foley catheter is placed through the bladder wall and secured in a long oblique tunnel away from the symphysis.

Suprapubic vs. urethral catheterization: the Cochrane review (Kidd et al.) found SPCs associated with less pain, lower rates of asymptomatic bacteriuria, and fewer recatheterizations than indwelling urethral catheters for short-term use.[24] However, insertion complications (bowel injury, catheter malpositioning) are underreported in trials, and the intraoperative complication rate in one NHS audit was 10%.[24]

Part IV: Rapid vs. gradual decompression — the evidence​

Principle 6 — Rapid, complete emptying is recommended​

"Clamping" the catheter to allow gradual decompression is a persistent clinical myth with no supporting evidence. The landmark Mayo Clinic review by Nyman et al. found:[3]

  • No randomized controlled trials have ever compared rapid vs. gradual decompression.
  • No studies support the practice of gradual emptying.
  • Rapid, complete emptying is safe, simple, effective, and recommended as the optimal method.

The potential complications of decompression — hematuria, hypotension, and postobstructive diuresis — occur regardless of the speed of emptying and are rarely clinically significant:[3]

ComplicationIncidenceSignificanceManagement
Hematuria (ex vacuo)2–16%Rarely clinically significant; decompression of overdistended mucosal vesselsUsually self-limited; continuous bladder irrigation if persistent; rarely requires intervention
HypotensionCommon (transient BP drop)Usually normalizes spontaneously; rarely progresses to clinically significant hypotensionIV fluid bolus if symptomatic; monitor elderly and hypovolemic patients closely
Postobstructive diuresis (POD)0.5–52%Usually physiologic and self-limited (<24 h); pathologic POD (>48 h) is rare but potentially lethalSee Part V below

Part V: Postobstructive diuresis — recognition and management​

Principle 7 — Physiologic vs. pathologic POD​

Postobstructive diuresis is defined as urine output ≥200 mL/hour for 2 consecutive hours or >3 L over 24 hours following relief of urinary obstruction.[25][26]

Physiologic POD — self-limited, <48 hours, self-resolving.

  • Represents the normal diuretic response to resolution of fluid overload and retained solute load.

Pathologic POD — >48 hours, potentially life-threatening.

  • Results from intrinsic tubular damage caused by prolonged obstruction.
  • Pathophysiology:[25][27][28]
    • Medullary washout — loss of the corticomedullary concentration gradient.
    • Downregulation of sodium transporters in the thick ascending limb of Henle.
    • Resistance to ADH (nephrogenic diabetes insipidus-like state).
    • Osmotic diuresis from retained urea.
    • Natriuresis from impaired tubular sodium reabsorption.
  • Can lead to severe dehydration, electrolyte derangements (hyponatremia, hypokalemia, hypomagnesemia), hypotension, and shock if not recognized and treated.[25][26]

Risk factors for pathologic POD:

  • Bilateral ureteral obstruction or obstruction of a solitary kidney.
  • Chronic retention with renal insufficiency (elevated BUN / creatinine).
  • Volume overload, CHF, or edematous states.
  • Prolonged duration of obstruction.[26]

Principle 8 — Management of POD​

  • Monitor urine output hourly for the first 24–48 hours after decompression in high-risk patients (chronic retention, elevated creatinine, bilateral obstruction).
  • Replace fluids judiciously — replace approximately 50–75% of urine output with 0.45% normal saline. Do not match output mL-for-mL, as this perpetuates the diuresis iatrogenically.[26][27]
  • Monitor electrolytes (Na, K, Mg, phosphate) every 6–12 hours during active diuresis.
  • Avoid overzealous fluid replacement — the most common iatrogenic error; converts physiologic POD into pathologic POD.[27]
  • Taper IV fluids as urine output decreases; transition to oral intake as tolerated.
  • Nephrology consultation for pathologic POD lasting >48 hours or associated with hemodynamic instability.[25]

Part VI: Post-decompression management — trial without catheter (TWOC)​

Principle 9 — Alpha-blocker therapy before TWOC​

The Cochrane review and EAU meta-analysis provide moderate-quality evidence that alpha-1 blockers significantly increase TWOC success rates:[29][30]

  • Alfuzosin — TWOC success 60% vs. 39% placebo (OR 2.28, 95% CI 1.55–3.36; 7 RCTs, 940 patients).[29]
  • Tamsulosin — TWOC success 47% vs. 29% placebo (OR 2.40, 95% CI 1.29–4.45; 3 RCTs, 297 patients).[29]
  • Alpha-blockers doubled the odds of successful TWOC in the Reten-World survey (OR 1.92, 95% CI 1.52–2.42).[5]
  • Alfuzosin and tamsulosin appear equally effective (very-low certainty).[29]
  • Adverse events are rare.[30]

Principle 10 — Timing and conduct of TWOC​

  • Optimal catheterization duration before TWOC — 1–3 days (median 3 days in worldwide practice).[2][23][5]
  • Catheterization >3 days does not improve TWOC success but is associated with increased morbidity (bacteriuria, fever, urosepsis) and prolonged hospitalization.[2][5]
  • Overall TWOC success rate — 23–61% depending on population and alpha-blocker use.[2][31][5]
  • Predictors of TWOC failure — age ≥70, prostate ≥50 g, severe LUTS, drained volume ≥1,000 mL, spontaneous (vs. precipitated) AUR.[5]
  • After failed TWOC — 49% undergo BPH surgery; 43.5% attempt a second TWOC (success rate 29.5%).[5]

Principle 11 — Surgical management after failed TWOC​

Emergency surgery (within days of AUR) carries greater morbidity and mortality than elective surgery and is discouraged.[2][23] Current practice favors:

  • Elective TURP — remains the gold standard for BPH-related AUR after failed TWOC.[23]
  • Laser enucleation (HoLEP, ThuLEP) — emerging alternatives with comparable efficacy.[23]
  • Clean intermittent self-catheterization (CISC) — a safe bridge to definitive surgery, particularly in patients with significant comorbidities precluding immediate surgery.[23]

Part VII: Special populations​

Clot retention​

Clot retention is a specific form of AUR caused by blood clots obstructing the bladder outlet or catheter. Management requires:

  • Large-bore catheter (20–24 Fr, 3-way) to facilitate manual irrigation and clot evacuation.
  • Continuous bladder irrigation with normal saline after clot evacuation.
  • If manual irrigation fails, cystoscopy with clot evacuation and fulguration of bleeding sources.
  • Identify and treat the underlying cause (bladder tumor, radiation cystitis, anticoagulation).

Acute bacterial prostatitis with retention​

A urinary catheter is indicated to relieve retention and drain infected urine. The JAMA review notes that a multidisciplinary expert panel deemed catheterization appropriate for PVR ≥500 mL (asymptomatic) or ≥300 mL (symptomatic).[9] Urethral catheterization is typically more practical than SPC, though SPC avoids manipulation through the infected gland.[9]

Neurogenic bladder​

Patients with AUR from neurologic causes (spinal cord injury, MS, cauda equina) should be managed long-term with clean intermittent catheterization (CIC), in conjunction with neurology and urology subspecialists.[1] Acute prolonged bladder overdistension from undetected retention (e.g., after regional anesthesia or prolonged labor) can cause irreversible detrusor damage — vigilant monitoring is paramount.[12]

Women with AUR​

AUR in women is uncommon and warrants thorough evaluation for:[4][7][8][10][11]

  • Pelvic organ prolapse (most common obstructive cause).
  • Uterine leiomyomas — especially posterior / fundal with retroverted uterus; can compress the urethra or pelvic plexus.[8]
  • Fowler's syndrome (young women with impaired urethral relaxation).[10]
  • Neurologic causes (most common in reproductive-age women).[4]
  • Psychological comorbidities and functional neurologic disorders (increasingly recognized).[11]

Part VIII: Catheter selection and infection prevention​

Catheter typeAdvantagesDisadvantagesBest indication
Urethral indwelling (Foley)Widely available; easy insertion; no special trainingUTI risk increases with duration; urethral trauma; patient discomfortShort-term AUR management; perioperative use
Suprapubic catheterLess pain; lower bacteriuria; easier hygiene; no urethral traumaRequires trained placement; bowel-injury risk (0–2.7%); requires distended bladderFailed urethral catheterization; long-term catheterization; urethral injury
Clean intermittent catheterizationLowest UTI risk; patient autonomy; no indwelling foreign bodyRequires dexterity and training; multiple daily insertionsNeurogenic bladder; bridge to surgery; chronic retention
Coudé-tip catheterNavigates prostatic urethra; reduced traumatic catheterization from 3.0% to 0.2%Requires proper orientation techniqueAll male catheterizations (per Miller et al.); BPH-related obstruction

Infection prevention:

  • Silver alloy-coated and antibiotic-impregnated catheters offer clinically insignificant or no benefit and are not routinely recommended.[1]
  • The single most important intervention is minimizing catheter dwell time — remove as soon as clinically indicated.[20]
  • CAUTI risk increases approximately 3–7% per day of catheterization.[20]

Summary — stepwise approach to AUR and emergent decompression​

  1. Confirm retention — bladder scanner preferred (≥300 mL symptomatic, ≥500 mL asymptomatic).[13]
  2. Rule out urethral injury in trauma — blood at meatus → RUG before catheterization.[14]
  3. Urethral catheterization — sterile technique, lidocaine gel, 14–16 Fr (coudé in males with BPH); inflate balloon only after urine drains.[15][14]
  4. Rapid, complete decompression — no clamping; drain the bladder fully.[3]
  5. Monitor for POD — hourly urine output for 24–48 hours in high-risk patients; replace 50–75% of output; monitor electrolytes.[26]
  6. Start alpha-blocker (alfuzosin or tamsulosin) at the time of catheterization.[29][30]
  7. TWOC at 1–3 days — remove catheter; assess voiding.[2][5]
  8. If TWOC fails — recatheterize → elective surgery (TURP / laser) or second TWOC attempt.[5]
  9. If urethral catheterization fails — escalate stepwise (coudé → guidewire → flexible cystoscopy → fluoroscopy-guided → suprapubic catheter).[16][17]

Cross-references​

References​

1. Serlin DC, Heidelbaugh JJ, Stoffel JT. "Urinary retention in adults: evaluation and initial management." Am Fam Physician. 2018;98(8):496–503.

2. Emberton M, Fitzpatrick JM. "The Reten-World survey of the management of acute urinary retention: preliminary results." BJU Int. 2008;101(Suppl 3):27–32. doi:10.1111/j.1464-410X.2008.07491.x

3. Nyman MA, Schwenk NM, Silverstein MD. "Management of urinary retention: rapid versus gradual decompression and risk of complications." Mayo Clin Proc. 1997;72(10):951–956. doi:10.1016/S0025-6196(11)63368-5

4. Andrada AO, De Vicente JM, Cidre MA. "Pelvic plexus compression due to a uterine leiomyoma in a woman with acute urinary retention: a new hypothesis." Int Urogynecol J. 2014;25(3):429–431. doi:10.1007/s00192-013-2158-z

5. Fitzpatrick JM, Desgrandchamps F, Adjali K, et al. "Management of acute urinary retention: a worldwide survey of 6074 men with benign prostatic hyperplasia." BJU Int. 2012;109(1):88–95. doi:10.1111/j.1464-410X.2011.10430.x

6. Cohn JA, Ni S, Kaufman MR, et al. "Urinary retention and catheter use among U.S. female Medicare beneficiaries: prevalence and risk factors." Neurourol Urodyn. 2017;36(8):2101–2108. doi:10.1002/nau.23248

7. Selius BA, Subedi R. "Urinary retention in adults: diagnosis and initial management." Am Fam Physician. 2008;77(5):643–650.

8. Wu CQ, Lefebvre G, Frecker H, Husslein H. "Urinary retention and uterine leiomyomas: a case series and systematic review of the literature." Int Urogynecol J. 2015;26(9):1277–1284. doi:10.1007/s00192-015-2665-1

9. Borgert BJ, Wallen EM, Pham MN. "Prostatitis." JAMA. 2025;334(11):1003–1013. doi:10.1001/jama.2025.11499

10. Szymański JK, Słabuszewska-Jóźwiak A, Jakiel G. "Fowler's syndrome — the cause of urinary retention in young women, often forgotten, but significant and challenging to treat." Int J Environ Res Public Health. 2021;18(6):3310. doi:10.3390/ijerph18063310

11. Panicker JN, Anding R, Arlandis S, et al. "Do we understand voiding dysfunction in women? Current understanding and future perspectives: ICI-RS 2017." Neurourol Urodyn. 2018;37(S4):S75–S85. doi:10.1002/nau.23709

12. Madersbacher H, Cardozo L, Chapple C, et al. "What are the causes and consequences of bladder overdistension? ICI-RS 2011." Neurourol Urodyn. 2012;31(3):317–321. doi:10.1002/nau.22224

13. Chrouser K, Fowler KE, Mann JD, et al. "Urinary retention evaluation and catheterization algorithm for adult inpatients." JAMA Netw Open. 2024;7(7):e2422281. doi:10.1001/jamanetworkopen.2024.22281

14. Johnsen N, Wessells H, Archer-Arroyo K, et al. Best Practices Guidelines: Management of Genitourinary Injuries. American College of Surgeons; 2025.

15. Miller D, Pelzman D, Bonfili J, et al. "Implementation of a standardized process of coudé catheter insertion decreases traumatic catheterizations." Urology. 2024;194:253–259. doi:10.1016/j.urology.2024.10.016

16. Willette PA, Coffield S. "Current trends in the management of difficult urinary catheterizations." West J Emerg Med. 2012;13(6):472–478. doi:10.5811/westjem.2011.11.6810

17. Beaghler M, Grasso M, Loisides P. "Inability to pass a urethral catheter: the bedside role of the flexible cystoscope." Urology. 1994;44(2):268–270. doi:10.1016/s0090-4295(94)80148-7

18. Bugeja S, Mistry K, Yim IHW, et al. "A new urethral catheterisation device (UCD) to manage difficult urethral catheterisation." World J Urol. 2019;37(4):595–600. doi:10.1007/s00345-018-2499-9

19. Kim SW, Nam IC, Kim DR, et al. "Safety and efficacy of fluoroscopy-guided urethral catheterization in case of failed blind or cystoscopy-assisted urethral catheterization." Sci Rep. 2024;14(1):9406. doi:10.1038/s41598-024-60224-1

20. Fletke KJ, Jeong DH, Herrera AV. "Urinary catheter management." Am Fam Physician. 2024;110(3):251–258.

21. Goyal NK, Goel A, Sankhwar SN. "Safe percutaneous suprapubic catheterisation." Ann R Coll Surg Engl. 2012;94(8):597–600. doi:10.1308/003588412X13373405385412

22. Aguilera PA, Choi T, Durham BA. "Ultrasound-guided suprapubic cystostomy catheter placement in the emergency department." J Emerg Med. 2004;26(3):319–321. doi:10.1016/j.jemermed.2003.11.016

23. Yoon PD, Chalasani V, Woo HH. "Systematic review and meta-analysis on management of acute urinary retention." Prostate Cancer Prostatic Dis. 2015;18(4):297–302. doi:10.1038/pcan.2015.15

24. Kidd EA, Stewart F, Kassis NC, Hom E, Omar MI. "Urethral (indwelling or intermittent) or suprapubic routes for short-term catheterisation in hospitalised adults." Cochrane Database Syst Rev. 2015;(12):CD004203. doi:10.1002/14651858.CD004203.pub3

25. Finger E, Moses A. "As the river flows: a case report of post-obstructive diuresis." BMC Nephrol. 2025;26(1):341. doi:10.1186/s12882-025-04215-y

26. Halbgewachs C, Domes T. "Postobstructive diuresis: pay close attention to urinary retention." Can Fam Physician. 2015;61(2):137–142.

27. Peterson LJ, Yarger WE, Schocken DD, Glenn JF. "Post-obstructive diuresis: a varied syndrome." J Urol. 1975;113(2):190–194. doi:10.1016/s0022-5347(17)59440-9

28. Baum N, Anhalt M, Carlton CE, Scott R. "Post-obstructive diuresis." J Urol. 1975;114(1):53–56. doi:10.1016/s0022-5347(17)66942-8

29. Karavitakis M, Kyriazis I, Omar MI, et al. "Management of urinary retention in patients with benign prostatic obstruction: a systematic review and meta-analysis." Eur Urol. 2019;75(5):788–798. doi:10.1016/j.eururo.2019.01.046

30. Fisher E, Subramonian K, Omar MI. "The role of alpha blockers prior to removal of urethral catheter for acute urinary retention in men." Cochrane Database Syst Rev. 2014;(6):CD006744. doi:10.1002/14651858.CD006744.pub3

31. Fitzpatrick JM, Kirby RS. "Management of acute urinary retention." BJU Int. 2006;97(Suppl 2):16–22. doi:10.1111/j.1464-410X.2006.06100.x