ACUTE URINARY RETENTION
Definition
Urinary retention is the inability to voluntarily urinate. Acute urinary retention (AUR) is the
sudden inability to empty the bladder despite having a full bladder.
HISTORY
Possible causes:
● Urological conditions: stones, vesicoureteral reflux, recurrent urinary tract infections.
● History of bladder catheterization.
● Comorbidities: diabetes, Parkinson’s disease, spinal cord injury, psychiatric disorders,
gastrointestinal disorders (constipation, diarrhea, fecal incontinence).
● Alcohol, coffee, or medication intake that can affect bladder function (see table
below).
PHYSICAL EXAMINATION
1. General examination to detect:
○ Dehydration
○ Edema or signs of congestive heart failure (may indicate fluid redistribution
problems leading to nocturia or enuresis)
2. Abdominal inspection:
○ Identify distension or fullness
○ Look for masses
○ Palpate and percuss the suprapubic area
○ Bladder examination: typically presents as a pelvic mass that may be visible, with
dull percussion note (if it contains 150 ml or more of urine), palpable (when there
is more than 200 ml of urine), and painful to palpation. In obese patients,
palpation may be difficult due to abdominal fat.
, 3. External genital and rectal examination:
○ Digital rectal exam: assess anal sphincter tone and presence of fecal impaction
○ Prostate exam: evaluate size, texture, and presence of nodules
○ Local neurological exam (assessment of perineal sensation, tissue atrophy) as
part of the pelvic exam in women
4. Neurological examination in suspected neurogenic bladder:
○ Bulbocavernosus reflex (contraction of bulbocavernosus muscle after glans
compression)
○ Anal reflex (anal sphincter contraction when perineal skin is pinched)
○ Voluntary pelvic contractions
○ Anal sphincter tone
○ Sensation of dermatomes S2 to S5
Considerations:
● In men over 50 years old, mechanical obstruction due to benign prostatic hyperplasia
(BPH) should be suspected as the main cause of AUR, often accompanied by lower
urinary tract symptoms (decreased urinary stream, terminal dribbling, nocturia, sensation
of incomplete emptying).
● In AUR patients with BPH, a digital rectal exam is recommended to assess the prostate.
The findings can help determine whether urethral catheterization will likely be successful,
allowing appropriate approach and avoiding urethral trauma.
● In AUR without lower urinary tract symptoms, consider causes such as:
• Infections
• Constipation
• Urethral stricture
• Excessive fluid intake (especially alcohol)
• Medication use
• Neurogenic causes
Definition
Urinary retention is the inability to voluntarily urinate. Acute urinary retention (AUR) is the
sudden inability to empty the bladder despite having a full bladder.
HISTORY
Possible causes:
● Urological conditions: stones, vesicoureteral reflux, recurrent urinary tract infections.
● History of bladder catheterization.
● Comorbidities: diabetes, Parkinson’s disease, spinal cord injury, psychiatric disorders,
gastrointestinal disorders (constipation, diarrhea, fecal incontinence).
● Alcohol, coffee, or medication intake that can affect bladder function (see table
below).
PHYSICAL EXAMINATION
1. General examination to detect:
○ Dehydration
○ Edema or signs of congestive heart failure (may indicate fluid redistribution
problems leading to nocturia or enuresis)
2. Abdominal inspection:
○ Identify distension or fullness
○ Look for masses
○ Palpate and percuss the suprapubic area
○ Bladder examination: typically presents as a pelvic mass that may be visible, with
dull percussion note (if it contains 150 ml or more of urine), palpable (when there
is more than 200 ml of urine), and painful to palpation. In obese patients,
palpation may be difficult due to abdominal fat.
, 3. External genital and rectal examination:
○ Digital rectal exam: assess anal sphincter tone and presence of fecal impaction
○ Prostate exam: evaluate size, texture, and presence of nodules
○ Local neurological exam (assessment of perineal sensation, tissue atrophy) as
part of the pelvic exam in women
4. Neurological examination in suspected neurogenic bladder:
○ Bulbocavernosus reflex (contraction of bulbocavernosus muscle after glans
compression)
○ Anal reflex (anal sphincter contraction when perineal skin is pinched)
○ Voluntary pelvic contractions
○ Anal sphincter tone
○ Sensation of dermatomes S2 to S5
Considerations:
● In men over 50 years old, mechanical obstruction due to benign prostatic hyperplasia
(BPH) should be suspected as the main cause of AUR, often accompanied by lower
urinary tract symptoms (decreased urinary stream, terminal dribbling, nocturia, sensation
of incomplete emptying).
● In AUR patients with BPH, a digital rectal exam is recommended to assess the prostate.
The findings can help determine whether urethral catheterization will likely be successful,
allowing appropriate approach and avoiding urethral trauma.
● In AUR without lower urinary tract symptoms, consider causes such as:
• Infections
• Constipation
• Urethral stricture
• Excessive fluid intake (especially alcohol)
• Medication use
• Neurogenic causes
