Patho: Chapter 35 (Disorders of bladder and lower urinary tract)

What happens in lower urinary tract obstruction and stasis?

Urine is produced normally by the kidneys but is retained in the bladder, which can predispose a person to kidney damage.

What congenital causes lead to lower urinary tract obstruction and stasis?

• Damage to sacral nerves

• Spina bifida

What acquired causes lead to lower urinary tract obstruction and stasis?

• Enlargement of the prostate gland

• Tumors compressing the bladder neck

• Tumors compressing the urethra

• External compression of the urethra

Will the body try to compensate for urine outflow obstruction?

Yes

What happens in the early stages of urine outflow obstruction?

• The bladder hypertrophies

• The bladder becomes hypersensitive to stretch receptor stimulation

• The ability to suppress urination decreases

• Bladder contractions become stronger

• Bladder spasms may occur

• Urinary incontinence may develop

What happens if urine outflow obstruction continues?

The compensatory hypertrophy mechanisms are no longer effective

What is spastic bladder dysfunction?

A neurogenic bladder disorder characterized by failure to relax and store urine

What causes spastic bladder dysfunction?

Neurologic lesions above the level of the sacral cord.

What happens in bladder overactivity with a failure to relax and store urine?

• Spastic bladder spasms occur

• Bladder volume decreases

• Urine storage is impaired

What can cause failure to store urine?

• Spinal cord injury

• Stroke

• Multiple sclerosis (MS)

• Tumor

• Herniated intervertebral disc

• Trauma

• Spina bifida

What is flaccid bladder dysfunction?

A neurogenic bladder disorder characterized by failure to contract and empty the bladder.

What causes flaccid bladder dysfunction?

Injury to the micturition center in the sacral cord or the sacral nerves that supply the bladder.

What are the characteristics/manifestations of flaccid bladder dysfunction?

• Atony (loss of tone) of the detrusor muscle

• Loss of bladder fullness sensation

• Overstretching of the detrusor muscle

• Weak bladder contractions

• Ineffective bladder emptying

What is urinary incontinence?

The involuntary loss or leakage of urine

What are the four types of urinary incontinence?

• Stress incontinence

• Urge incontinence

• Overflow incontinence

• Nocturnal enuresis

What is stress incontinence?

The involuntary loss of urine during coughing, laughing, sneezing, or other activities that increase intra-abdominal pressure.

What causes stress incontinence?

Pelvic floor muscle dysfunction or weakness

What is urge incontinence?

The involuntary loss of urine associated with a strong desire to void.

What causes urge incontinence?

Hyperactivity of the detrusor muscle

What is overflow incontinence?

The involuntary loss of urine when intravesical pressure exceeds maximal urethral pressure in the absence of detrusor activity due to bladder distension.

What causes overflow incontinence?

• Nervous system lesions

• Obstruction of the bladder neck

What is nocturnal enuresis?

The loss of urine at night

Who commonly experiences nocturnal enuresis?

Children

What is the most common sign of bladder cancer?

Painless hematuria

What are urothelial cells?

Transitional epithelial cells that line the bladder

What are 90-95% of bladder cancers derived from?

Urothelial cells

What is a benign papiloma?

A rare benign tumor that grows in finger-like projection from the epithelial surface

Can benign papillomas progress to tumors?

Yes

What is the most common type of bladder cancer?

Urothelial carcinoma

What is a Urinary Tract Infection (UTI)?

An infection of the urinary tract caused by microorganism, usually bacteria that enter through the urethra or bloodstream.

What bacteria most commonly cause uncomplicated lower UTIs?

Escherichia coli (E. coli), a gram-negative rod-shaped bacterium

What other bacteria can cause uncomplicated lower UTIs?

• Enterococcus faecalis

• Klebsiella pneumoniae

• Pseudomonas species

What is washout phenomenon?

The normal flushing of bacteria out of the urethra by urine flowing from the bladder.

What is the most common portal of entry for microbes that cause UTIs?

The urethra

What are the risk factors for lower Urinary Tract Infections (UTIs)?

• Urinary obstruction or reflux

• Postmenopausal women

• Pregnancy

• Men with prostate disease

• Diabetes

• Increased age

• Urinary catheterization

Why does urinary catheterization increase the risk of a UTI?

Bacteria can adhere to the catheter and bladder, promoting infection.

What is the most common gram-negative bladder infection found in hospitalized patients?

Catheter-induced infection

A 56-year-old client reports urinary incontinence when laughing. The nurse documents this as which type of incontinence?

Stress

Disruption of which muscle’s contraction can lead to the inability to expel urine from the bladder?

Detrusor