In a 30-year-old woman with acute urinary retention and urgency who cannot pass a standard 16-French Foley catheter, what is the appropriate next step?

Inability to Insert Foley Catheter in a 30-Year-Old Woman

In a young woman with acute urinary retention where a standard Foley catheter cannot be passed, immediately perform bedside ultrasound to assess for bladder distension and rule out anatomical obstruction, then attempt catheterization with a smaller caliber catheter (12-14 Fr) using generous lubrication—if this fails, proceed directly to suprapubic catheter placement rather than repeated traumatic attempts. 1

Immediate Assessment and Initial Management

Rule Out Urethral Injury First

• Do not make repeated blind attempts at catheter insertion, as this increases the risk of creating or extending urethral injury and delays definitive drainage 1
• In women, urethral injury from trauma is rare but can occur with pelvic fractures or recent pelvic surgery 1
• If there is any history of recent pelvic surgery, consider that the "blockage" may represent surgical injury to the urethra or bladder neck 1

Bedside Ultrasound Evaluation

• Perform immediate bladder ultrasound to confirm significant urinary retention (typically >600 mL in acute retention) and verify the bladder is indeed full 1, 2
• Ultrasound can also identify anatomical abnormalities, masses, or bladder neck obstruction that may be causing the difficulty 1

Stepwise Approach to Catheter Placement

First Attempt Modifications

• Use a smaller caliber catheter (12-14 Fr) rather than the standard 16 Fr, as urethral stricture or spasm may be preventing passage 1
• Apply generous water-soluble lubricant and allow time for the lubricant to provide anesthetic effect 1
• In women, ensure proper identification of the urethral meatus (common error is attempting to catheterize the vagina) 3
• Position the patient in lithotomy position with adequate lighting and visualization 3

If Initial Attempt Fails

• Consider coude-tip catheter, which has an angled tip that may navigate past anatomical obstacles more easily 3
• Have an experienced clinician make a single additional attempt only 1
• Do not persist with multiple traumatic attempts—this causes urethral injury, bleeding, and false passages 1

Definitive Management When Urethral Catheterization Fails

Suprapubic Catheter Placement

• Proceed to suprapubic catheter (SPT) placement if urethral catheterization cannot be accomplished after appropriate attempts 1
• SPT can be placed percutaneously at the bedside under ultrasound guidance or via open technique 1
• SPT offers several advantages: avoids urethral trauma, allows for urethral healing if injury occurred, and provides reliable drainage 1, 4
• Ultrasound guidance is essential to confirm bladder distension and avoid bowel injury during percutaneous placement 1

When to Obtain Urology Consultation

• Immediate urology consultation is indicated if you suspect urethral stricture, anatomical abnormality, or if SPT placement is not within your scope of practice 3
• Suspected urethral injury (though rare in women without pelvic trauma) requires specialist evaluation 1
• Consider gynecology consultation if pelvic mass or anatomical distortion is suspected 3

Common Causes of Difficult Catheterization in Young Women

Anatomical Considerations

• Urethral stricture (rare in young women but can occur from prior instrumentation, infection, or trauma) 3
• Urethral spasm from anxiety, pain, or recent instrumentation 5
• Pelvic organ prolapse causing urethral kinking or obstruction 3
• Vaginal/urethral anatomical variants or congenital abnormalities 3

Functional Causes to Address

• Medications causing retention: anticholinergics, opioids, antihistamines, decongestants, antipsychotics 5
• Review medication list and discontinue offending agents if possible 5
• Neurogenic bladder from spinal cord pathology or multiple sclerosis 3

Critical Pitfalls to Avoid

• Never make repeated forceful attempts at urethral catheterization—this creates false passages and worsens the situation 1
• Do not delay bladder decompression while pursuing diagnostic workup—acute retention requires urgent drainage to prevent bladder injury 1, 4
• Do not assume the problem is simply "technique" after 2-3 failed attempts by experienced providers—there is likely an anatomical or pathological cause 3
• Avoid inflating the balloon if there is any resistance during catheter advancement, as this may indicate the catheter is not fully in the bladder 6

Post-Drainage Management

Immediate Monitoring

• Once drainage is established (urethral or suprapubic), monitor for post-obstructive diuresis, which can occur after relieving acute retention 4, 3
• Replace urinary losses if diuresis exceeds 200 mL/hour to prevent hypovolemia 3
• Monitor renal function, as acute retention can cause obstructive uropathy 1

Diagnostic Workup

• Obtain urinalysis and culture to rule out infection as a contributing factor 1, 3
• Consider pelvic ultrasound or CT to evaluate for masses, stones, or anatomical abnormalities causing obstruction 1
• Arrange outpatient urology follow-up for cystoscopy and urodynamic evaluation to determine the underlying cause 2, 3

Definitive Treatment Planning

• If SPT was placed, it should remain until the underlying cause is identified and treated 1
• Small caliber percutaneous catheters may require upsizing for long-term use 1
• Plan for definitive management based on the identified cause (stricture dilation, surgical correction of anatomical abnormality, etc.) 1, 3