see also:

• urology
• benign prostatic hyperplasia (BPH)
• the patient unable to pass urine (anuria)
• AAFP - Mx of acute urinary retention in detail
• UpToDate

• failed void and bladder volume > 300mL confirmed with > 400mL drained on catheterisation
• see the patient unable to pass urine (anuria)

• benign prostatic hyperplasia (BPH)
  • most common cause of AUR in older men
  • a 60yr old with mod-severe symptoms of BPH has a ~14% chance of developing retention over next 10 yrs
  • risk of retention increases with:
    • age
    • severity of obstructive symptoms
    • prostatic volume
    • PSA > 2.5
    • if PH retention and no Rx, 50% will have recurrence within 1 wk, and 2/3rds in 1 year
    • acute precipitant
• urinary tract infections (UTIs) / cystitis
• prostatitis most common cause in younger men but also in men with BPH
• neurogenic bladder (eg. cauda equina syndrome (CES))
• pharmacologic esp. in men with BPH
  • anti-muscarinic anticholinergic agents reduce detrusor contractility and bladder sensation
  • sympathomimetics increase smooth muscle tone in the region of the bladder neck (eg. nasal decongestants)
  • opiates and opioids reduce bladder sensation
• post-op or post-partum
• severe pain
• Herpes simplex virus (HSV)
• herpes zoster (shingles)
• vulvovaginitis
• acute bladder distension with inefficient detrusor muscle eg. iv fluid challenge
• urethral trauma
• urethral diverticulum
• urethral stricture
• phimosis
• paraphimosis
• bladder cancer
• prostate cancer
• constipation
• renal calculi
• anatomic - eg. prolapse, pelvic masses, incarcerated retroverted uterus ~10wks gestation

• low threshold for suspecting urinary retention in the elderly in particular - bladder scan
• if bladder scan > 300mL and patient unable to void:
  • NB. C/I to urethral catheterisation: (consider US guided suprapubic catheter or urology consult instead)
    • recent urologic surgery such as radical prostatectomy
    • urethral strictures
    • acute bacterial prostatitis as risk of septicaemia (although an experienced operator may attempt a gentle catheterisation)
  • if no C/I, place 14-18F urinary catheter to decompress the bladder
    • if difficulty passing catheter:
      • if PH TURP, consider 10-12F catheter
      • if benign prostatic hyperplasia (BPH) and no TURP, consider 20-22F catheter with a firm coude tip +/- urology consult
    • if medication induced or other transient cause such as UTI, then consider in-out catheter
    • if the retention is associated with BPH and high pressure and hydronephrosis on USS then TOV is C/I and patient should be referred to urology reg for TURP
    • in other situations, leave the catheter in situ for at least 3 days for a Trial of Void
      • if benign prostatic hyperplasia (BPH):
        • commence tamsulosin (if no C/I) well prior to Trial of Void as this increases success rate by 50%
        • if Trial of Void fails twice then refer for surgery (TURP reduces risk of recurrence of retention by ~90%)
        • factors favoring successful TOV (only 20-40% of BPH patients will have a successful 1st TOV):
          • age < 65yrs
          • detrusor pressure greater than 35 cm H2O
          • < 1L drained at decompression
          • precipitating event
        • successful TOV patients with BPH have high risk of recurrence of retention - mostly in the following week - ~50% with 1 week, ~2/3rds within 1 year and thus should be commenced on an alpha-1-adrenergic blocker and a 5-alpha reductase inhibitor such as Duodart, as an alpha-1-adrenergic blocker reduced risk of recurrence in 1st 3 months by ~50% and in 1st 6 months by ~30% while the 5-alpha reductase inhibitor has a longer term effect requiring 12 months of Rx
  • clamping the catheter drain tube to slow rate of decompression does NOT seem to be beneficial in reducing adverse effects
  • observe for adverse effects:
    • haematuria - ~10% of patients having an IDC but rarely is an issue - if large clots, will need a 3-way catheter to be inserted to allow bladder washouts to prevent catheter blockage from clots
    • transient hypotension does not usually require Rx
    • post-obstructive diuresis (POD)
      • more common with relief of chronic retention rather than acute retention
      • if initial urine drained > 700mL then monitor subsequent urine output hourly for 6hrs to exclude POD
      • POD is indicated by > 200mL urine output over two hours
      • if POD then monitor fluid balance including urine output, and give iv N Saline (may require other crystalloids pending serum Na level) to replace half the urine output volume
      • if POD persists > 48hrs or is severe, contact urology for possible admission

• in general, elderly patients with delirium should have regular post-void bladder scans and if in retention, an in/out catheter up to two times before considering IDC
• some patients, particularly women who develop retention due to opiates, etc, should be considered for in-out catheter and trial of void in ED

• some patients who develop acute urinary retention may be suitable for a trial of void within hours of IDC being inserted - in particular, those with an acute cause such as use of opiates for pain
• those with constipation should have this addressed prior to TOV
• if being admitted to a ED short stay unit overnight, it may be best to remove the IDC at midnight rather than 6am and this will generally allow earlier discharge and higher voiding volumes ¹⁾
• optional active voiding protocol
  • this allows a shorter trial of void time by prefilling the bladder with saline
  • Instill 250-400 cc of STERILE SALINE via the lumen of the Foley catheter into the bladder via gravity drainage or slow push
  • Clamp the Foley
  • Deflate the catheter balloon and remove the catheter from the bladder.
  • Record the amount of saline that was instilled into the bladder.
  • Immediately assist the patient to void. Report the amount instilled and the amount voided to the physician within one hour a. Unless the patient reports extreme bladder fullness or pain, give the patient one hour to urinate
  • If the patient fails the voiding trial, the doctor to decide to do in and out catheterization or place a new Foley catheter

• high risk patients should be referred to urology as likely to need TURP:
  • BPH with high pressure obstruction - hydronephrosis

• low risk adult patients could potentially aim to have a TOV within 3-4 days ²⁾
• however, for adult patients with acute urinary retention within Western Health ED's should have:
  • instructions for Mx of leg bag
  • provided with leg bags
  • referred to the DPU retention clinic at Western Hospital by faxing to 56205:
    • a Day Procedure Unit booking form (AD 32) PLUS,
  • fax a Community Access Referral Form for PACFU (AD 172) to fax 56529
  • fax to outpatients on 56856, an outpatient appointment referral form for retention clinic (along with the ED discharge letter)
  • if you can follow all the above you deserve a medal!
  • DPU will contact patient to arrange a trial of void - current wait list is around 6 weeks
  • urology request all patients with prostatism (? urinary retention requiring an IDC) be prescribed Duodart (Tamsulosin/Dutasteride 400mcg/500mcg, dosed 1 tablet once a day) prior to the trial of void. All patients being commenced on Duodart need to be discussed with the Urology Registrar or consultant on duty.
    • This is not within PBS authority guidelines unless “initiated by a urologist for Rx of lower urinary symptoms due to benign prostatic hyperplasia” and thus may need to be notated as “non-PBS” but fortunately at $35 is similar in price to a PBS dispensation.