Urinary retention: Clinical sciences

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Introduction0:00–0:31

Urinary retention refers to a condition characterized by the inability to voluntarily empty the urinary bladder. It can be acute or chronic, ranging from partial to complete urinary retention.
Based on the underlying cause, urinary retention can occur due to spinal cord compression or injury; or as a result of medication side effects; urethral obstruction; or urinary tract infection.Now, if your patient presents with urinary retention, your first step is to obtain a focused history and physical examination.

Focused H&P0:31–2:12

Alright, let’s start with individuals that present with acute urinary retention. These patients typically report sudden inability to voluntarily void in combination with a sudden lower abdominal pain.
On your physical exam, you will typically notice suprapubic tenderness and palpable bladder. These findings are highly suggestive of acute urinary retention.
Now, let’s go back and take a look at patients with chronic urinary retention. These individuals typically report a gradual inability to voluntarily void and lower abdominal discomfort or pain.
Some patients might report symptoms of urinary tract infection, such as fever and dysuria, while others might report use of medications associated with urinary retention.
Finally, history might reveal benign prostate hyperplasia or diabetes mellitus. On the physical exam, again, you will notice suprapubic tenderness and palpable bladder.
These history and physical exam findings are highly suggestive of chronic urinary retention! Now, here’s a clinical pearl to keep in mind!
In biologically female individuals, assess for potential pelvic masses or organ prolapse, which can also result in urinary retention!
Additionally, in all patients, you can order an ultrasound to check whether or not the bladder is full, and you can also assess for hydronephrosis.Now, once you diagnose urinary retention, you should always consider bladder decompression using a urethral or suprapubic catheter.

Bladder decompression2:12–3:01

This way you will eliminate accumulated urine from the bladder and relieve painful sensations. Keep in mind that bladder decompression is typically reserved for individuals with acute urinary retention, but, on rare occasions, you could decompress the bladder in individuals with chronic urinary retention as well.
Next, assess your patient for neurological red flags, such as bilateral weakness of lower extremities and decreased rectal tone, which could indicate a spinal cord compression, like Cauda Equina Syndrome.
Let’s say your patient presents with neurological red flags. In this case, you should definitely be worried about spinal cord involvement, such as compression from herniated discs, spinal fractures, or tumors; as well as injury from trauma.

Spinal cord compression/injury3:01–4:02

Your next step is to order imaging, more specifically an MRI of the spine! If the MRI reveals a spinal lesion, mass, or injury, you can diagnose urinary retention due to spinal cord compression or injury, and immediately consult your surgery team.Now, here’s a clinical pearl to keep in mind!
Other conditions, such as diabetes mellitus and multiple sclerosis, can cause urinary retention due to neurogenic bladder.
However, these patients may not experience the neurological red flags of decreased anal sphincter tone or bilateral lower extremity weakness.Ok, now let’s go back and take a look at patients with no neurological red flags.

Medication-induced urinary retention4:02–5:01

In this case, first, you should ask your patient about medications associated with urinary retention, such as anticholinergics, antipsychotics, antihistamines, antidepressants, and opioids.If your patient is taking one of these medications, you can diagnose medication-induced urinary retention.
Your next step is to discontinue the offending medication or replace it with a safer option. Once the patient stops taking the offending medication, urinary retention should resolve.However, if your patient is not using any medications associated with urinary retention, proceed with the additional workup and order labs.
These can include CBC, BMP; prostate specific antigen or PSA; as well as urinalysis and urine culture.Let’s go over our first scenario, where urinary retention is due to obstruction.

Obstruction5:01–7:09

Labs may reveal elevated creatinine and PSA, while urinalysis and urine culture would be negative for infection. Additionally, on the digital rectal exam, you may detect an enlarged prostate.
These findings are highly suggestive of obstructive urinary retention due to an enlarged prostate; most commonly, this is due to benign prostatic hyperplasia or BPH.
Here’s a clinical pearl! If a patient presents with obstructive urinary retention due to enlarged prostate, the most common cause is benign prostatic hyperplasia, which predominantly involves the transitional zone that surrounds the urethra.
For this anatomical reason, BPH may sometimes not be detected on digital rectal exam, yet it can still compress the urethra, leading to urinary retention.
However, make sure to rule out prostate cancer, which is more commonly found in the peripheral zone, located farther away from the urethra, but in advanced stages it can grow enough to compress the urethra.
Okay, after you diagnose BPH, management involves medical therapy with alpha-adrenergic blockers, such as tamsulosin or terazosin; phosphodiesterase type 5 inhibitors, like tadalafil; or 5 alpha-reductase inhibitors like finasteride.
Both alpha-adrenergic blockers and phosphodiesterase type 5 inhibitors relax the bladder and prostate so urine can flow more easily; while 5 alpha-reductase inhibitors prevent the conversion of testosterone into its more potent form, dihydrotestosterone, inhibiting it from promoting further prostate growth.
Additionally, for patients with more severe symptoms or complications like recurrent UTIs, you could consult your surgical team for possible transurethral resection of the prostate, or TURP for short.Speaking of UTIs, our next cause of urinary retention is infection.

Infection7:09–7:53

In this case, the CBC would demonstrate a high white blood cell count; urinalysis would reveal elevated leukocyte esterase with or without nitrites; and a urine culture would come back positive for a specific pathogen, such as bacteria or fungi.
Some important infections to keep in mind include cystitis and prostatitis, which are associated with localized edema, and subsequent obstruction of the urine flow and eventual urinary retention.
Your next step is to treat the infection with antibiotics, tailoring based on the urine culture.Alright, as a quick recap… Urinary retention refers to a condition characterized by the inability to voluntarily empty the urinary bladder.

Review7:53–8:42

It can be acute or chronic, ranging from partial to complete urinary retention. Once you diagnose urinary retention, first, you should consider bladder decompression with a urinary or suprapubic catheter.
Next, assess the patient for neurological red flags, such as bilateral weakness of lower extremities and decreased anal sphincter tone.
If they do have neurological red flags, think of spinal cord compression or injury, order an MRI of the spine, and immediately consult your surgery team.
However, if there are no neurological red flags, you should consider medication side effects, urethral obstruction, or urinary tract infection.