complete course on acute urinary retention, with definition, epidemiology, etiologies, diagnosis, management, prognosis, and complications

1. Acute urinary retention
TSAMO NDOMO V. MD,MPH

2. Plan
Introduction
Epidemiology
Etiologies
Diagnostic approach
Management
Prognosis
Complications
Conclusion

3. Introduction
 Urinary retention is the inability to void urine voluntarily.
 It can be acute or chronic.
 It is a common medical problem across the globe, and acute retention can
be a urologic emergency that occurs most commonly in men.
 Acute urinary retention in men is most commonly secondary to benign
prostatic hyperplasia (BPH).
 Acute urinary retention in women is rare.
 Our current analysis will be centered on acute urinary retention in men.

4. Epidemiology
 Acute urinary retention is most common in men in their 60s to 80s.
 About 10% of men over age 70 and close to one-third in their 80s will
develop acute urinary retention.
 The risk for this in men is prostatic enlargement, with risk factors of
increasing age, African American race, obesity, diabetes mellitus, high
alcohol consumption, and physical inactivity.
 Neurogenic causes of urinary retention tend to occur in younger males
and women.
 The mortality rate for men with spontaneous urinary retention at 1-year
increases from 4.1% in patients ages 45 to 54 years to 33% in those 85
years and older.
 Acute urinary retention represents 45.05% of all urological emergencies in
Cameroon.(Ngalle et Al, 2023).

5. Etiologies of Acute urinary retention
 Causes of urinary retention are numerous and categorized as obstructive,
infectious, inflammatory, pharmacologic, neurologic, or other.
 Obstructive causes of urinary retention
 The mechanisms of acute urinary retention can include outflow obstruction, which
can be mechanical such as from physical narrowing of the urethral channel.
 The other dynamic is from an increase in the muscle tone within and around the
urethra as in with benign prostatic hypertrophy and hyperplasia.
 Other obstructive causes can occur by constipation, cancer of the prostate or bladder,
urethral stricture, urolithiasis, phimosis, or paraphimosis.

6. Etiologies of Acute urinary retention
Infections
 The most common cause of infectious acute urinary retention is acute
prostatitis.
 acute prostatitis is usually caused by gram-negative organisms, such as
Escherichia coli and Proteus species.
 Urethritis from a urinary tract infection (uTi) or sexually transmitted
infection cause urethral edema with resultant urinary retention.
 Genital herpes may cause urinary retention from local inflammation and
sacral nerve involvement (elsberg syndrome).

7. Etiologies of Acute urinary retention
Neurologic causes
 Neurologic impairment, another etiology of urinary retention, is because of the
interruption of the sensory or motor innervation of the detrusor muscle.
 The process of voluntary urination involves the integration and coordination of
high cortical neurologic functions involving sympathetic, parasympathetic, and
somatic nerves and the detrusor and sphincter smooth muscle.
 Discernment of a full bladder is by nerves sensing pressure creating a sensory
impulse to the cortical centers, allowing the cortical areas to coordinate
voluntary urination, which leads to continence of the bladder storing urine
through relaxation of the detrusor muscle through beta-adrenergic stimulation
and parasympathetic inhibition.

8. Etiologies of Acute urinary retention
The contraction of the bladder detrusor muscle(voiding) is
brought on by cholinergic muscarinic receptors and relaxation of
the internal sphincter, the bladder neck, and the urethral sphincter
through alpha-adrenergic inhibition.
The dyssynergia occurs by interruption of the neurologic pathways
such as from a stroke, spinal cord injury, infarction, demyelination
along with other neurologic disorders (e.g., traumatic cord injuries,
epidural abscess, epidural metastasis, Guillain-Barre syndrome,
diabetic neuropathy, multiple sclerosis).
These neurologic impairments may develop acute on chronic
urinary retention

9. Etiologies of Acute urinary retention
Muscle dysfunction
Inefficient detrusor muscle can cause acute urinary retention and can be
brought on by the result of the fluid challenge, during general or epidural
analgesia without an indwelling catheter.
Patients with symptoms of obstructive uropathy at baseline are most at risk
for this.
Muscle dysfunction
Inefficient detrusor muscle can cause acute urinary retention and can be
brought on by the result of the fluid challenge.
During general or epidural analgesia without an indwelling catheter.
Patients with symptoms of obstructive uropathy at baseline are most at risk
for this.

10. Etiologies of Acute urinary retention
Medications
 Medications can cause acute urinary retention by their effects on
neurotransmitters, neuroreceptors, cholinergic, and muscarinic receptors.
 Other etiologies such as trauma and operative procedures can cause
urinary retention by altering the anatomy or injury of the bladder,
sphincter, or the urethra.
 These agents act through a variety of mechanisms; some are apparent
such as sympathomimetics and anticholinergic, and there effects on
smooth muscle tone of the urethra or bladder neck and the detrusor
muscle.

11. Drugs that can induce acute urinary retention, Brian et Al, 2008

12. Clinical presentation: History
 The history of the patient presenting with symptoms of acute urinary retention
should focus on lower urinary tract symptoms using questions such as, "Over the
past month:“
1. How frequently have you had the sensation of not being able to empty your bladder
completely after voiding?
2. How frequently have you had to urinate again less than two hours after finished urinating?
3. How frequently have you found you stopped and started several times when you were
voiding?
4. How often have you have found it difficult to postpone urination?
5. Over the past month, how often have you had a weak stream?
6. How often have you had to push or strain to begin urination?
7. How many times did you get up to urinate from the time you go to bed until you get up
in the morning?

13. Clinical presentation: History
The American Urological Association developed a scoring system
using these question using a rating scale:
Not at all=0
Less than 1 time in 5 = 1
Less than half the time = 2
About half the time = 3
More than half the time = 4
Almost always = 5
This scoring system helps identify mild symptoms (0 to 7), moderate
symptoms (8 to 19), and severe symptoms (20 to 35) related to the
prostate as a cause.

14. Clinical presentation: History
 The clinician should inquire about the history of prostate diseases such as
cancer, trauma, surgery, kidney stones, prostate infections, sexually
transmitted infections, radiation treatment or exposure, and back pain.
 History on the presence of hematuria, dysuria, fever, low back pain,
neurologic symptoms of tremors, weakness is vital.
 A thorough urogenital review of systems is a must.
 The medication list should undergo thorough review as several
medications can cause urinary retention, and inquiry into past surgical
procedures, and anesthesia may also prove informative.

15. Clinical presentation: Physical Exam
 The physical examination should focus on the lower quadrants of the
abdomen, pelvis, and genitals.
 Palpation can often note the distended bladder;
 The rectal exam can note an enlarged prostate (showing prostatic
hyperplasia) or fecal impaction (showing impingement on the bladder
neck or urethra), or poor sphincter tone (showing a spinal cord problem).
 Neurologic examination for strength, sensation, reflexes, and muscle
tone is also informative.
 Thorough patient history and physical exam will often identify the
etiology.

16. Paraclinical Investigations
 The evaluation should consist of:
 A urine sample obtained by having the patient void on their own and checking pre
and post-void residuals with a bladder scanner, or placement of a Foley catheter.
 Chemistries: sodium, potassium, bicarbonate, chloride, blood urea nitrogen and
creatinine.
 A complete blood count
 If neurologic signs and symptoms are present on examination and there is suspicion
of stroke, CT of the head
 If spinal cord processes are suspected, MRI
 Evaluation by urology and other appropriate specialists to aid in the diagnosis of the
etiology will proceed based on the findings of the history and physical.

17. Paraclinical Investigations
The diagnosis of acute urinary retention is aided by
bladder ultrasound, but catheterization is reasonable as it
is both diagnostic and therapeutic.
The bladder ultrasound that suggests a volume greater
than or equal to 300 mL in a patient unable to void
suggests urinary retention.
Bladder ultrasound can be inaccurate because of body
habitus, tissue edema, prior surgery, and scarring.
The placement of a catheter might be needed.

18. Paraclinical Investigations
The volume of urine obtained from drainage in the first 10 to
15 minutes should be recorded.
If the volume exceeds 400 mL, the catheter will typically remain
in place.
For volumes of 200 to 400 mL, the decision to leave the
catheter in place is guided by the clinical scenario as volumes
less than 200 mL likely do not have acute urinary retention and
should undergo evaluation for other causes of abdominal or
suprapubic discomfort.

19. Paraclinical investigations for patients with AUR, Brian et Al, 2008

20. Management
Aims:
Relieve the pain/discomfort related to urine retention
Treat the underlying cause
Prevent complications

21. Management
As the patient with acute urinary retention is in discomfort
placement of a urinary catheter or suprapubic catheter (if the
urethra is not accessible) should to decompress the bladder
and relieve the lower tract obstruction.
Urethral catheterization is contraindicated in patients with
recent urologic surgery such as radical prostatectomy or
urethral reconstruction.
These patients should have suprapubic catheterization (SPC)

22. Management
For patients who had to have a suprapubic catheter due to
contraindications or failed urethral catheterization, the urologist
usually places suprapubic catheters.
In emergent conditions where a urologist is not present, and the
patient is in distress, suprapubic aspiration via a needle is an option.
The underlying etiology determines the duration of catheterization.
In the patients where the underlying etiology is temporary, such as with
medications or anesthetic should have a post-voiding trial as soon as
possible. within 2 to 3 days.
In patients with a spinal injury where urinary retention is not likely to resolve,
catheterization may become chronic.

23. Management
The underlying etiology, such as infection, should receive
treatment.
Benign prostatic hyperplasia should receive medical treatment
and evaluation for surgical intervention such as transurethral
resection.
Patients who have urosepsis, obstruction due to malignancy,
acute myelopathy, acute renal failure, electrolytes imbalance
should be admitted.

24. Prognosis
Men with BPH who develop acute urinary retention are usually
greater than 70, with more comorbidities and have a higher risk of
complications.
These comorbidities include infection and renal dysfunction, such as
chronic kidney disease (CKD) and end-stage renal disease (ESRD).
He prognosis is determined by response to therapy.
The older the patient, the higher the risk of complications.
The use of modalities of intermittent catheterization and suprapubic
catheterization has been shown to result in fewer complications.

25. Complications
 complications from acute urinary retention are from the underlying causes and
treatments.
 They include infection, renal dysfunction, electrolyte imbalances, stricture of the
urethra, bladder neck dilation, and detrusor muscle dysfunction.
 The treatment via catheterization for bladder decompression can result in
adverse events such as hematuria, which occurs between 2 to 16 percent of the
patients but is rarely significant.
 This complication usually resolves with irrigation.
 Transient hypotension is a complication that occurs after initial bladder
decompensation, but it is transient, and blood pressure normalizes without
intervention.
 Post obstructive diuresis may persist after decompression of the bladder.

26. In fine
Acute urinary retention is an emergency situation and has to
be diagnosed and treated accordingly.
The main etiologies are generally mechanical, infectious,
neurogenic,muscular, medicinal.
The diagnosis is mostly clinical and ultrasounds is
confirmatory.
The treatment mainly depends of the etiology.
Always seek urologist consultations for complicated cases.