Overflow incontinence is defined as the involuntary loss of urine associated with bladder overdistention in the absence of detrusor contraction. This condition classically occurs in men who have outlet obstruction secondary to prostatic enlargement that progresses to urinary retention. In women this is a relatively uncommon cause of urinary incontinence. When it does occur, it can be from increased outlet resistance from advanced vaginal prolapse causing a "kink" in the urethra or after an anti-incontinence procedure which has overcorrected the problem. Additionally, it can result from bladder hyporeflexia from a variety of neurologic causes (Table 45-9).
Overflow incontinence most often occurs due to postoperative obstruction if the bladder neck is overcorrected, or with a hyporeflexic bladder due to neurologic disease or spinal cord injury. The normal act of voiding is controlled centrally by sacral and pontine micturition centers. Impaired emptying can be the result of disruption of either central or peripheral neurons mediating detrusor function. Failure to identify the cause early may lead to permanent dysfunction and may lead to injury to the detrusor muscle or compromise in the parasympathetic ganglia in the bladder wall.
Usually symptoms are loss of urine without awareness or intermittent dribbling and constant wetness. Suprapubic pressure or pain may be associated. Patients will often note a sensation of a full bladder and the need to strain in order to empty or apply suprapubic pressure to void. Patients are at risk for urinary tract infection secondary to persistent residual urine in the bladder, which acts as a medium for bacterial growth. It is commonly seen after a bladder neck suspension. Complaints of poor urinary stream and sense of incomplete emptying combined with having to strain or apply hand pressure to void are likely.
Evaluation should always include a postvoid residual and, if the diagnosis is questionable, voiding pressure flow studies. An imaging study of the upper urinary tract to evaluate the ureters and kidney should follow, because persistent high-volume retention can lead to reflux and hydroureter or hydronephrosis and renal injury if left unchecked.
Overflow incontinence happens when the normal flow of urine is blocked and the bladder cannot empty completely. Overflow incontinence can be due to a number of conditions:
- A partial obstruction. In this case the urine cannot flow completely out of the bladder, so it never fully empties.
- An inactive bladder muscle. In contrast to urge incontinence (overactive bladder), with overflow incontinence the bladder is less active than normal, not more. It cannot empty properly and so becomes distended, or swollen. Eventually this distention stretches the internal sphincter until it opens partially and leakage occurs.
Causes of overflow incontinence include:
- Certain medications (such as anticholinergics, antidepressants, antipsychotics, sedatives, narcotics, and alpha-adrenergic blockers)
- Benign prostatic hyperplasia (enlarged prostate) - in Men
- Scar tissue
- Nerve damage. When nerves in the bladder are damaged the body cannot feel when the bladder is full and the bladder does not contract. Nerve damage can be caused by spinal cord injuries, previous surgery in the colon or rectum, or pelvic fractures. Diabetes, multiple sclerosis, and shingles also can cause this problem.
The International Continence Society (ICS) defines SUI as the complaint of involuntary leakage on effort or exertion, or on coughing or sneezing ...
Diagnosis of overflow incontinence
If you have problems with incontinence, it is important to seek medical advice. Determining the type you have and the best treatment for it will begin with describing the problem. Your doctor may ask questions such as:
- How often do you go to the toilet?
- When you go to the toilet, do you have trouble starting or stopping the flow of urine?
- Do you leak urine during certain activities?
- Do you leak constantly?
- Do you leak urine before you get to the toilet?
- Do you experience pain or burning when you urinate?
- Do you get frequent urinary tract infections?
- Have you had a back injury?
- Do you have a medical condition that could interfere with bladder function?
Next, your doctor will perform a physical examination and look for signs of damage to the nerves that affect the bladder and rectum. Depending on the findings of the examination, your doctor may refer you to a neurologist (a doctor who specialises in diagnosing and treating diseases of the nervous system), a urologist (who specialises in problems of the bladder and urinary system) or arrange for you to have further tests.
Bladder drainage to relieve retention is the first priority. Self-intermittent or prolonged catheterization may be necessary, depending on resolution of the inciting cause. In cases of postoperative urinary retention, bladder function can be evaluated by serial postvoid residual urine determinations. Although no normal volume for residual urine is universally accepted, it less than 100 mL is generally considered to be within normal limits and greater than 150 mL is considered abnormal. More than one value is needed because persistently high residual volumes will require prolonged catheterization.
- Urinary Incontinence
- Urinary Incontinence - Overview
L Patient Questionnaires
L Voiding Diary
L Physical Examination
L Cotton Swab Test
L Urinary Cough Stress Test
L Neurologic Examination
L Imaging Tests
- Stress Urinary Incontinence
- Urge Urinary Incontinence
- Mixed Incontinence
- Overflow Incontinence
- Bypass Incontinence
- Functional and transient incontinence
When urinary retention occurs in the setting of neurologic disease, diabetes, or stroke, correction of the underlying cause is often impossible; therefore, the goal is to prevent injury or damage to the upper urinary tract. Intermittent self-catheterization is preferable to an indwelling catheter, which may predispose to infection, bladder spasms, or erosion.
Medical therapy may assist in the care of these patients. Acetylcholine agonists can stimulate detrusor contractions in patients that have vesical areflexia. α -Adrenergic blockers can facilitate bladder emptying by relaxing tone at the bladder neck.
Behavior modification in the form of timed voiding on a preset schedule to empty regardless of urge will prevent accumulation of excess urine. Usually a voiding pattern of every 2-3 hours is preferable. In bladder areflexia, manual pressure or abdominal splinting may facilitate emptying.
How is it treated?
Women can be treated for overflow incontinence with:
- A catheter. A catheter is a thin, flexible tube that allows urine to drain out. It is inserted into the bladder through the urethra. Different types of catheters include:
Intermittent self-catheterization: A woman inserts a clean catheter when it is necessary to urinate, usually 3 or 4 times a day.
Indwelling Foley catheter- The catheter remains in place continuously. Urinary tract infections are more likely to occur with long-term use of an indwelling catheter than with intermittent self-catheterization.
- Surgery. Surgery may be needed to correct problems that cause overflow incontinence, such as obstructions or abnormal growths in the urinary tract.
Medicines are rarely used to treat overflow incontinence in women.
Men can be treated for overflow incontinence with:
Surgery. Overflow incontinence caused by an enlarged prostate is often treated with surgery to remove the obstruction, including transurethral resection of the prostate (TURP), a common procedure used to treat BPH.
A catheter. Some men may need a catheter to allow the bladder to empty normally.
Medicine. Medicines can be used to make the prostate smaller. This relieves pressure on the urethra so the bladder can empty more normally. Medicines can also help the urine flow better.