Neurogenic Bladder - Diabetes and Neurogenic Bladder

Neurogenic Bladder

Neurogenic Bladder
May 22, 2006
Raymond Rackley, MD
eMedicine.com

INTRODUCTION

The normal function of the urinary bladder is to store and expel urine in a coordinated, controlled fashion. This coordinated activity is regulated by the central and peripheral nervous systems. Neurogenic bladder is a term applied to a malfunctioning urinary bladder due to neurologic dysfunction or insult emanating from internal or external trauma, disease, or injury.

Symptoms of neurogenic bladder range from detrusor underactivity to overactivity, depending on the site of neurologic insult. The urinary sphincter also may be affected, resulting in sphincter underactivity or overactivity and loss of coordination with bladder function. The appropriate therapy and a successful outcome are predicated upon accurate diagnosis through a careful medical and voiding history together with a variety of clinical examinations, including urodynamics and selective radiographic imaging studies.


NEUROANATOMY

Normal voiding essentially is a spinal reflex that is modulated by the central nervous system (brain and spinal cord), which coordinates the functions of the bladder and urethra. The bladder and urethra are innervated by 3 sets of peripheral nerves arising from the autonomic nervous system (ANS) and somatic nervous system. The central nervous system is composed of the brain, brain stem, and the spinal cord.

Brain

The brain is the master control of the entire urinary system.

The micturition control center is located in the frontal lobe of the brain. The primary activity of this area is to send tonically inhibitory signals to the detrusor muscle to prevent the bladder from emptying (contracting) until a socially acceptable time and place to urinate is available.

Certain lesions or diseases of the brain, including stroke, cancer, or dementia, result in loss of voluntary control of the normal micturition reflex.

The signal transmitted by the brain is routed through 2 intermediate stops (the brainstem and the sacral spinal cord) prior to reaching the bladder.

Brainstem

The brainstem is located at the base of the skull. Within the brainstem is a specialized area known as the pons, a major relay center between the brain and the bladder. The pons is responsible for coordinating the activities of the urinary sphincters and the bladder so that they work in synergy. The mechanical process of urination is coordinated by the pons in the area known as the pontine micturition center (PMC). The PMC coordinates the urethral sphincter relaxation and detrusor contraction to facilitate urination.

The conscious sensations associated with bladder activity are transmitted to the pons from the cerebral cortex. The interaction of a variety of excitatory and inhibitory neuronal systems is the function of the PMC, which is characterized by its inborn excitatory nature. The PMC functions as a relay switch in the voiding pathway. Stimulation of the PMC causes the urethral sphincters to open while facilitating the detrusor to contract and expel the urine.

The PMC is affected by emotions, which is why some people may experience incontinence when they are excited or scared. The ability of the brain to control the PMC is part of the social training that children experience during growth and development. Usually the brain takes over the control of the pons at age 3-4 years, which is why most children undergo toilet training at this age.

When the bladder becomes full, the stretch receptors of the detrusor muscle send a signal to the pons, which in turn notifies the brain. People perceive this signal (bladder fullness) as a sudden desire to go to the bathroom. Under normal situations, the brain sends an inhibitory signal to the pons to inhibit the bladder from contracting until a bathroom is found.

When the PMC is deactivated, the urge to urinate disappears, allowing the patient to delay urination until finding a socially acceptable time and place. When urination is appropriate, the brain sends excitatory signals to the pons, allowing the urinary sphincters to open and the detrusor to empty.

Spinal cord

The spinal cord extends from the brainstem down to the lumbosacral spine. It is located in the spinal canal and is protected by the cerebrospinal fluid, meninges, and a vertebral column. It is approximately 14 inches long in an adult. Along its course, the spinal cord sprouts off many nerve branches to different parts of the body.

The spinal cord functions as a long communication pathway between the brainstem and the sacral spinal cord. When the sacral cord receives the sensory information from the bladder, this signal travels up the spinal cord to the pons and then ultimately to the brain. The brain interprets this signal and sends a reply via the pons that travels down the spinal cord to the sacral cord and, subsequently, to the bladder.

In the normal cycle of bladder filling and emptying, the spinal cord acts as an important intermediary between the pons and the sacral cord. An intact spinal cord is critical for normal micturition.

If spinal cord injury has occurred, the patient will demonstrate symptoms of urinary frequency, urgency, and urge incontinence but will be unable to empty his or her bladder completely. This occurs because the urinary bladder and the sphincter are both overactive, a condition termed detrusor sphincter dyssynergia with detrusor hyperreflexia (DSD-DH).

The sacral spinal cord is the terminal portion of the spinal cord situated at the lower back in the lumbar area. This is a specialized area of the spinal cord known as the sacral reflex center. It is responsible for bladder contractions. The sacral reflex center is the primitive voiding center.

In infants, the higher center of voiding control (the brain) is not mature enough to command the bladder, which is why control of urination in infants and young children comes from signals sent from the sacral cord. When urine fills the infant bladder, an excitatory signal is sent to the sacral cord. When this signal is received by the sacral cord, the spinal reflex center automatically triggers the detrusor to contract. The result is involuntary detrusor contractions with coordinated voiding.

A continuous cycle of bladder filling and emptying occurs, which is why infants and young children are dependent on diapers until they are toilet trained. As the child's brain matures and develops, it gradually dominates the control of the bladder and the urinary sphincters to inhibit involuntary voiding until complete control is attained. Voluntary continence usually is attained by age 3-4 years. By this time, control of the voiding process has been relinquished by the sacral reflex center of the sacral cord to the higher center in the brain.

If the sacral cord becomes severely injured (eg, spinal tumor, herniated disc), the bladder may not function. Affected patients may develop urinary retention, termed detrusor areflexia. The detrusor will be unable to contract, so the patient will not be able to urinate and urinary retention will occur.

Peripheral nerves

Peripheral nerves form an intricate network of pathways for sending and receiving information throughout the body. The nerves originate from the main trunk of the spinal cord and branch out in different directions to cover the entire body. Nerves convert the internal and external environmental stimuli to electrical signals so that the human body can understand stimuli as one of the ordinary senses (ie, hearing, sight, smell, touch, taste, equilibrium). The bladder and the urethral sphincters are under the influence of their corresponding nerves.

The ANS lies outside of the central nervous system. It regulates the actions of the internal organs (eg, intestines, heart, bladder) under involuntary control. The ANS is divided into the sympathetic and the parasympathetic nervous system.

Under normal conditions, the bladder and the internal urethral sphincter primarily are under sympathetic nervous system control. When the sympathetic nervous system is active, it causes the bladder to increase its capacity without increasing detrusor resting pressure (accommodation) and stimulates the internal urinary sphincter to remain tightly closed. The sympathetic activity also inhibits parasympathetic stimulation. When the sympathetic nervous system is active, urinary accommodation occurs and the micturition reflex is inhibited.

The parasympathetic nervous system functions in a manner opposite to that of the sympathetic nervous system. In terms of urinary function, the parasympathetic nerves stimulate the detrusor to contract. Immediately preceding parasympathetic stimulation, the sympathetic influence on the internal urethral sphincter becomes suppressed so that the internal sphincter relaxes and opens. In addition, the activity of the pudendal nerve is inhibited to cause the external sphincter to open. The result is facilitation of voluntary urination.

Like the ANS, the somatic nervous system is a part of the nervous system that lies outside of the central spinal cord. The somatic nervous system regulates the actions of the muscles under voluntary control. Examples of these muscles are the external urinary sphincter and the pelvic diaphragm. The pudendal nerve originates from the nucleus of Onuf and regulates the voluntary actions of the external urinary sphincter and the pelvic diaphragm. Activation of the pudendal nerve causes contraction of the external sphincter and the pelvic floor muscles, which occurs with activities such as Kegel exercises. Difficult or prolonged vaginal delivery may cause temporary neurapraxia of the pudendal nerve and cause stress urinary incontinence. Conversely, suprasacral-infrapontine spinal cord trauma can cause overstimulation of the pudendal nerve that results in urinary retention.

PHYSIOLOGY AND PATHOPHYSIOLOGY

Physiology

During the course of a day, an average person will void approximately 4-8 times. The urinary bladder is in storage mode for most of the day, allowing an individual to engage in more important activities than urination.

Normal bladder function consists of 2 phasesÛfilling and emptying. The normal micturition cycle requires that the urinary bladder and the urethral sphincter work together as a coordinated unit to store and empty urine. During urinary storage, the bladder acts as a low-pressure receptacle, while the urinary sphincter maintains high resistance to urinary flow to keep the bladder outlet closed. During urine elimination, the bladder contracts to expel urine while the urinary sphincter opens (low resistance) to allow unobstructed urinary flow and bladder emptying.

Filling phase

During the filling phase, the bladder accumulates increasing volumes of urine while the pressure inside the bladder remains low. The pressure within the bladder must be lower than the urethral pressure during the filling phase. If the bladder pressure is greater than the urethral pressure (resistance), urine will leak out.

The filling of the urinary bladder depends on the intrinsic viscoelastic properties of the bladder and the inhibition of the parasympathetic nerves. Thus, bladder filling primarily is a passive event.

Sympathetic nerves also facilitate urine storage in the following ways:

* Sympathetic nerves inhibit the parasympathetic nerves from triggering bladder contractions.
* Sympathetic nerves directly cause relaxation and expansion of the detrusor muscle.
* Sympathetic nerves close the bladder neck by constricting the internal urethral sphincter. This sympathetic input to the lower urinary tract is constantly active during bladder filling.

As the bladder fills, the pudendal nerve becomes excited. Stimulation of the pudendal nerve results in contraction of the external urethral sphincter. Contraction of the external sphincter, coupled with that of the internal sphincter, maintains urethral pressure (resistance) higher than normal bladder pressure. The combination of both urinary sphincters is known as the continence mechanism.

The pressure gradients within the bladder and urethra play an important functional role in normal micturition. As long as the urethral pressure is higher than that of the bladder, patients will remain continent. If the urethral pressure is abnormally low or if the intravesical pressure is abnormally high, urinary incontinence will result.

As the bladder initially fills, a small rise in pressure occurs within the bladder (intravesical pressure). When the urethral sphincter is closed, the pressure inside the urethra (intraurethral pressure) is higher than the pressure within the bladder. While the intraurethral pressure is higher than the intravesical pressure, urinary continence is maintained.

During some physical activities and with coughing, sneezing, or laughing, the pressure within the abdomen rises sharply. This rise is transmitted to both the bladder and urethra. As long as the pressure is evenly transmitted to both the bladder and urethra, urine will not leak. When the pressure transmitted to the bladder is greater than urethra, urine will leak out, resulting in stress incontinence.

Emptying phase

The storage phase of the urinary bladder can be switched to the voiding phase either involuntarily (reflexively) or voluntarily. Involuntary reflex voiding occurs in an infant when the volume of urine exceeds the voiding threshold. When the bladder is filled to capacity, the stretch receptors within the bladder wall signal the sacral cord. The sacral cord, in turn, sends a message back to the bladder indicating that it is time to empty the bladder.

At this point, the pudendal nerve causes relaxation of the levator ani so that the pelvic floor muscle relaxes. The pudendal nerve also signals the external sphincter to open. The sympathetic nerves send a message to the internal sphincter to relax and open, resulting in a lower urethral resistance.

When the urethral sphincters relax and open, the parasympathetic nerves trigger contraction of the detrusor. When the bladder contracts, the pressure generated by the bladder overcomes the urethral pressure, resulting in urinary flow. These coordinated series of events allow unimpeded, automatic emptying of the urine.

A repetitious cycle of bladder filling and emptying occurs in newborn infants. The bladder empties as soon as it fills because the brain of an infant has not matured enough to regulate the urinary system. Because urination is unregulated by the infant's brain, predicting when the infant will urinate is difficult.

As the infant brain develops, the PMC also matures and gradually assumes voiding control. When the infant enters childhood (usually at age 3-4 years), this primitive voiding reflex becomes suppressed and the brain dominates bladder function, which is why toilet training usually is successful at age 3-4 years. However, this primitive voiding reflex may reappear in people with spinal cord injuries.

Delaying voiding or voluntary voiding

Bladder function is automatic but completely governed by the brain, which makes the final decision on whether or not to void. The normal function of urination means that an individual has the ability to stop and start urination on command. In addition, the individual has the ability to delay urination until a socially acceptable time and place. The healthy adult is aware of bladder filling and can willfully initiate or delay voiding.

In a healthy adult, the PMC functions as an on-off switch that is activated by stretch receptors in the bladder wall and is, in turn, modulated by inhibitory and excitatory neurologic influences from the brain. When the bladder is full, the stretch receptors are activated. The individual perceives the activation of the stretch receptors as the bladder being full, which signals a need to void.

When an individual cannot find a bathroom nearby, the brain bombards the PMC with a multitude of inhibitory signals to prevent detrusor contractions. At the same time, an individual may actively contract the levator muscles to keep the external sphincter closed or initiate distracting techniques to suppress urination.

Thus, the voiding process requires coordination of both the ANS and somatic nervous system, which are in turn controlled by the PMC located in the brainstem.
Pathophysiology

If a problem occurs within the nervous system, the entire voiding cycle is affected. Any part of the nervous system may be affected, including the brain, pons, spinal cord, sacral cord, and peripheral nerves. A dysfunctional voiding condition results in different symptoms, ranging from acute urinary retention to an overactive bladder or to a combination of both.

Urinary incontinence results from a dysfunction of the bladder, the sphincter, or both. Bladder overactivity (spastic bladder) is associated with the symptoms of urge incontinence, while sphincter underactivity (decreased resistance) results in symptomatic stress incontinence. A combination of detrusor overactivity and sphincter underactivity may result in mixed symptoms.

Brain lesion

Lesions of the brain above the pons destroy the master control center, causing a complete loss of voiding control. The voiding reflexes of the lower urinary tractÛthe primitive voiding reflexÛremain intact. Affected individuals show signs of urge incontinence, or spastic bladder (medically termed detrusor hyperreflexia or overactivity). The bladder empties too quickly and too often, with relatively low quantities, and storing urine in the bladder is difficult. Usually, people with this problem rush to the bathroom and even leak urine before reaching their destination. They may wake up frequently at night to void.

Typical examples of a brain lesion are stroke, brain tumor, or Parkinson disease. Hydrocephalus, cerebral palsy, and Shy-Drager syndrome also are brain lesions. Shy-Drager syndrome is a rare condition that also causes the bladder neck to remain open.

Spinal cord lesion

Diseases or injuries of the spinal cord between the pons and the sacral spinal cord also result in spastic bladder or overactive bladder. People who are paraplegic or quadriplegic have lower extremity spasticity. Initially, after spinal cord trauma, the individual enters a spinal shock phase where the nervous system shuts down. After 6-12 weeks, the nervous system reactivates. When the nervous system becomes reactivated, it causes hyperstimulation of the affected organs. For example, the legs become spastic.

These people experience urge incontinence. The bladder empties too quickly and too frequently. The voiding disorder is similar to that of the brain lesion except that the external sphincter may have paradoxical contractions as well. If both the bladder and external sphincter become spastic at the same time, the affected individual will sense an overwhelming desire to urinate but only a small amount of urine may dribble out. The medical term for this is detrusor-sphincter dyssynergia because the bladder and the external sphincter are not in synergy. Even though the bladder is trying to force out urine, the external sphincter is tightening to prevent urine from leaving.

The causes of spinal cord injuries include motor vehicle and diving accidents. Multiple sclerosis (MS) is a common cause of spinal cord disease in young women. Those with MS also may exhibit visual disturbances, known as optic neuritis. Children born with myelomeningocele may have spastic bladders and/or an open urethra. Conversely, some children with myelomeningocele may have a hypocontractile bladder instead of a spastic bladder.

Sacral cord injury

Selected injuries of the sacral cord and the corresponding nerve roots arising from the sacral cord may prevent the bladder from emptying. If a sensory neurogenic bladder is present, the affected individual may not be able to sense when the bladder is full. In the case of a motor neurogenic bladder, the individual will sense the bladder is full and the detrusor may not contract, a condition known as detrusor areflexia. These individuals have difficulty eliminating urine and experience overflow incontinence; the bladder gradually overdistends until the urine spills out. Typical causes are a sacral cord tumor, herniated disc, and injuries that crush the pelvis. This condition also may occur after a lumbar laminectomy, radical hysterectomy, or abdominoperineal resection.

Some teenagers suddenly develop an abnormal voiding pattern and often are evaluated for tethered cord syndrome, a neurologic condition in which the tip of the sacral cord is stuck near the sacrum and cannot stretch as the child grows taller. Ischemic changes of the sacral cord associated with the tethering cause the manifestation of dysfunctional voiding symptoms.

Peripheral nerve injury

Diabetes mellitus and AIDS are 2 of the conditions causing peripheral neuropathy resulting in urinary retention. These diseases destroy the nerves to the bladder and may lead to silent, painless distention of the bladder. Patients with chronic diabetes lose the sensation of bladder filling first, before the bladder decompensates. Similar to injury to the sacral cord, affected individuals will have difficulty urinating. They also may have a hypocontractile bladder.

Other diseases manifesting this condition are poliomyelitis, Guillain-Barr» syndrome, severe herpes in the genitoanal area, pernicious anemia, and neurosyphilis (tabes dorsalis).

Summary of definitions

* Neurogenic bladder is a malfunctioning bladder due to any type of neurologic disorder.
* Detrusor hyperreflexia refers to overactive bladder symptoms due to a suprapontine upper motor neuron neurologic disorder. External sphincter functions normally. The detrusor muscle and the external sphincter function in synergy (in coordination).
* DSD-DH refers to overactive bladder symptoms due to neurologic upper motor neuron disorder of the suprasacral spinal cord. Paradoxically, the patient is in urinary retention. Both the detrusor and the sphincter are contracting at the same time; they are in dyssynergy (lack of coordination).
* Detrusor hyperreflexia with impaired contractility (DHIC) refers to overactive bladder symptoms, but the detrusor cannot generate enough pressure to allow complete emptying. The external sphincter is in synergy with detrusor contraction. The detrusor is too weak to mount an adequate contraction for proper voiding to occur. The condition is similar to urinary retention, but irritating voiding symptoms are prevalent.
* Detrusor instability refers to overactive bladder symptoms without neurologic impairment. External sphincter functions normally, in synergy.
* Overactive bladder refers to symptoms of urinary urgency, with or without urge incontinence, usually associated with frequency and nocturia. The cause may be neurologic or nonneurologic.
* Detrusor areflexia is complete inability of the detrusor to empty due to a lower motor neuron lesion (eg, sacral cord or peripheral nerves).
* Urinary retention is the inability of the urinary bladder to empty. The cause may be neurologic or nonneurologic.


TYPES OF NEUROGENIC BLADDERS

Supraspinal lesions

Supraspinal lesions refer to those lesions of the central nervous system involving the area above the pons. They include cerebrovascular accident, brain tumor, Parkinson disease, and Shy-Drager syndrome.

* Cerebrovascular accident
*
o After a stroke, the brain may enter into a temporary acute cerebral shock phase. During this time, the urinary bladder will be in retentionÛdetrusor areflexia. Almost 25% of affected individuals develop acute urinary retention after a stroke.
o After the cerebral shock phase wears off, the bladder demonstrates detrusor hyperreflexia with coordinated urethral sphincter activity. This occurs because the PMC is released from the cerebral inhibitory center. When the patient manifests symptoms of detrusor hyperreflexia, the individual will complain of urinary frequency, urgency, and urge incontinence.
o The treatment for the cerebral shock phase is indwelling Foley catheter or clean intermittent catheterization (CIC). When the bladder becomes hyperreflexic, institute therapies to facilitate bladder filling and storage with anticholinergic medications.
* Brain tumor
*
o Detrusor hyperreflexia with coordinated urethral sphincter is the most common observed urodynamic pattern associated with a brain tumor.
o When the patient manifests symptoms of detrusor hyperreflexia, the individual complains of urinary frequency, urgency, and urge incontinence. First-line treatment for detrusor hyperreflexia includes anticholinergic medication.
* Parkinson disease
*
o This is a degenerative disorder of pigmented neurons of substantia nigra. It results in dopamine deficiency and increased cholinergic activity in the corpus striatum.
o Patients with Parkinson disease manifest symptoms of bradykinesia, skeletal muscle tremor, cogwheel rigidity, and masked facies. Symptoms specific to the urinary bladder include urinary frequency, urgency, nocturia, and urge incontinence.
o Typical urodynamic findings for Parkinson disease are most consistent with detrusor hyperreflexia and urethral sphincter bradykinesia. The striated urethral sphincter often demonstrates poorly sustained contraction.
o Similar to other supraspinal lesions, the treatment for Parkinson disease is to facilitate bladder filling and promote urinary storage with anticholinergic agents.
o If patients with Parkinson disease exhibit symptoms of bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE), the diagnosis of BOO should be confirmed by multichannel urodynamic studies. The most common cause of postprostatectomy incontinence in the patient with Parkinson disease is detrusor hyperreflexia.
o If transurethral resection of the prostate (TURP) is performed without urodynamic confirmation of obstruction, the patient may become totally incontinent after the TURP procedure.
* Shy-Drager syndrome
*
o Shy-Drager syndrome is a rare, progressive, and degenerative disease affecting the ANS with multisystem organ atrophy. In addition to Parkinson-like symptoms, cerebellar ataxia and autonomic dysfunction are common. Affected individuals demonstrate orthostatic hypotension, anhidrosis, and urinary incontinence.
o Degeneration of the nucleus of Onuf results in denervation of the external striated sphincter. Sympathetic nerve atrophy causes nonfunctional bladder and an open bladder neck.
o Urodynamic evaluation often reveals detrusor hyperreflexia, although a few individuals may have detrusor areflexia or poorly sustained bladder contractions. Often, the bladder neck (internal sphincter) will be open at rest, with striated sphincter denervation.
o The treatment for Shy-Drager syndrome is to facilitate urinary storage with anticholinergic agents coupled with CIC or indwelling catheter. Patients with Shy-Drager syndrome should avoid undergoing TURP because the risk of total incontinence is high.

Spinal cord lesions

* Spinal cord injury
*
o When an individual sustains a spinal cord injury from a diving accident or motor vehicle injury, the initial response from the nervous system is spinal shock. During this spinal shock phase, the affected individual experiences flaccid paralysis below the level of injury, and the somatic reflex activity is either depressed or absent.
o The anal and bulbocavernosus reflex typically is absent. The autonomic activity is depressed, and the individual experiences urinary retention and constipation. Urodynamic findings are consistent with areflexic detrusor and rectum. The internal and external urethral sphincter activities, however, are normal.
o The spinal shock phase typically lasts 6-12 weeks; it may be prolonged in some cases. During this time, the urinary bladder must be drained with CIC or indwelling urethral catheter.
o When the spinal shock phase wears off, bladder function returns but the detrusor activity increases in reflex excitability to an overactive stateÛdetrusor hyperreflexia. Depending on the level of the lesion, the individual may develop DSD-DH. Thus, the individual must be monitored for leaking between CIC, and periodic urodynamic testing must be performed for this alteration in detrusor behavior. During urodynamics, intravesical instillation of cold saline may indicate return of reflex activity or help better characterize the lesion.
o Realizing that suprasacral lesions exhibit detrusor areflexia at initial insult but progress to hyperreflexic state over time is important. Conversely, sacral cord lesions are associated with areflexic bladders that may become hypertonic overtime.
* Spinal cord lesions (above the sixth thoracic vertebrae)
*
o Individuals who sustain a complete cord transection above the sixth thoracic vertebrae (T6) most often will have urodynamic findings of detrusor hyperreflexia, striated sphincter dyssynergia, and smooth sphincter dyssynergia. A unique complication of T6 injury is autonomic dysreflexia.
o Autonomic dysreflexia is an exaggerated sympathetic response to any stimuli below the level of the lesion. This occurs most commonly with lesions of the cervical cord. Often, the inciting event is instrumentation of the urinary bladder or the rectum, causing visceral distention.
o Symptoms of autonomic dysreflexia include sweating, headache, hypertension, and reflex bradycardia. Acute management of autonomic dysreflexia is to decompress the rectum or bladder. Decompression usually will reverse the effects of unopposed sympathetic outflow. If additional measures are required, parenteral ganglionic or adrenergic blocking agents, such as chlorpromazine, may be used.
o Oral blocking agents, including terazosin, may be used for prophylactically treating patients with autonomic dysreflexia. Alternatively, spinal anesthetic may be used as a prophylactic measure whenever bladder instrumentation is considered.
* Spinal cord lesions (below T6)
*
o Individuals who sustain spinal cord lesions below T6 level will have urodynamic findings of detrusor hyperreflexia, striated sphincter dyssynergia, and smooth sphincter dyssynergia but no autonomic dysreflexia.
o Neurologic evaluation will reveal skeletal muscle spasticity with hyperreflexic deep tendon reflexes. Affected patients will demonstrate extensor plantar response and positive Babinski sign.
o These individuals will experience incomplete bladder emptying secondary to detrusor sphincter dyssynergia, or loss of facilitatory input from higher centers. Cornerstone of treatment involves CIC and anticholinergic medications.
* Multiple sclerosis
*
o MS is caused by focal demyelinating lesions of the central nervous system. It most commonly involves the posterior and lateral columns of the cervical spinal cord. Usually, poor correlation exists between the clinical symptoms and urodynamic findings. Thus, using urodynamic studies to evaluate patients with MS is critical.
o The most common urodynamic finding is detrusor hyperreflexia, occurring in as many as 50-90% of patients with MS. As many as 50% of patients will demonstrate DSD-DH. Detrusor areflexia occurs in 20-30% of cases. The optimum therapy for a patient with MS and incontinence must be individualized and based on the urodynamic findings.

Peripheral nerve lesions

Peripheral nerve lesions due to diabetes mellitus, tabes dorsalis, herpes zoster, herniated lumbar disk disease, and radical pelvic surgery result in detrusor areflexia.

* Diabetic cystopathy
*
o Usually, neurogenic bladder dysfunction occurs 10 or more years after the onset of diabetes mellitus. Neurogenic bladder occurs because of autonomic and peripheral neuropathy. A metabolic derangement of the Schwann cell results in segmental demyelination and impaired nerve conduction.
o The first symptoms of diabetic cystopathy are loss of sensation of bladder filling followed by loss of motor function. Classic urodynamic findings associated with this condition are elevated residual urine, decreased bladder sensation, impaired detrusor contractility, and, eventually, detrusor areflexia. Paradoxically, DHIC also has been observed. Treatment of diabetic cystopathy is CIC, long-term indwelling catheterization, or urinary diversion.
* Tabes dorsalis (neurosyphilis)
*
o In tabes dorsalis, central and peripheral nerve conduction is impaired. Affected patients experience decreased bladder sensation and increased voiding intervals.
o The most common urodynamic finding associated with neurosyphilis is detrusor areflexia with normal sphincteric function.
* Herpes zoster
*
o Herpes zoster is a neuropathy associated with painful vesicular eruptions in the distribution of the affected nerve. The herpes virus lies dormant in the dorsal root ganglia or the sacral nerves.
o Sacral nerve involvement leads to impairment of detrusor function. The early stages of herpes infection are associated with lower urinary tract symptoms of urinary frequency, urgency, and urge incontinence. Later stages include decreased bladder sensation, increased residual urine, and urinary retention. Urinary retention is self-limited and will resolve spontaneously with clearing of the herpes infection.
* Herniated disc
*
o Slow and progressive herniation of the lumbar disc may cause irritation of the sacral nerves and cause detrusor hyperreflexia. Conversely, acute compression of the sacral roots associated with deceleration trauma will prevent nerve conduction and result in detrusor areflexia.
o A typical urodynamic finding of sacral nerve injury is detrusor areflexia with intact bladder sensation. Associated internal sphincter denervation may occur. If the peripheral sympathetic nerves are damaged, the internal sphincter will be open and nonfunctional. Peripheral sympathetic nerve damage often occurs in association with detrusor denervation. The striated sphincter, however, is preserved.
* Pelvic surgery
*
o Patients undergoing major pelvic surgery, such as radical hysterectomy, abdominoperineal resection, proctocolectomy, or total exenteration will experience bladder dysfunction postoperatively.
o Most commonly, postsurgical patients will manifest symptoms of detrusor areflexia. However, as many as 80% of affected patients will experience spontaneous recovery of function within 6 months after surgery.


WORKUP

Lab studies

* Urinalysis and urine culture: Urinary tract infection can cause irritative voiding symptoms and urge incontinence.
* Urine cytology: Carcinoma-in-situ of the urinary bladder causes symptoms of urinary frequency and urgency. Irritative voiding symptoms out of proportion to the overall clinical picture and/or hematuria warrant urine cytology and cystoscopy.
* Chem 7 profile: Blood urea nitrogen (BUN) and creatinine (Cr) are checked if compromised renal function is suspected.

Other Tests

* Voiding diary: A voiding diary is a daily record of the patient's bladder activity. It is an objective documentation of the patient's voiding pattern, incontinent episodes, and inciting events associated with urinary incontinence.
* Pad test
*
o This is an objective test that documents the urine loss. Intravesical methylene blue test or oral Pyridium or Urised may be used. Methylene blue and Urised turns the urine color blue; Pyridium turns the urine color orange.
o Patients should resume their usual physical activities while wearing a Peri-pad. If the pads turn to orange or blue, the patient is experiencing urine loss. If the pads remain white, moisture most likely is a normal vaginal fluid.

Diagnostic Procedures

* Postvoid residual urine
*
o The postvoid residual urine (PVR) measurement is a part of basic evaluation for urinary incontinence.
o If the PVR is high, the bladder may be contractile or the bladder outlet may be obstructed. Both of these conditions will cause urinary retention with overflow incontinence.
* Uroflow rate
*
o Uroflow rate is a useful screening test used mainly to evaluate bladder outlet obstruction. Uroflow rate is volume of urine voided per unit of time.
o Low uroflow rate may reflect urethral obstruction, a weak detrusor, or a combination of both. This test alone cannot distinguish an obstruction from a contractile detrusor.
* Filling cystometrogram
*
o A filling cystometrogram (CMG) assesses the bladder capacity, compliance, and the presence of phasic contractions (detrusor instability). Most commonly, liquid filling medium is used.
o An average adult bladder holds approximately 50-500 mL of urine. During the test, provocative maneuvers help to unveil bladder instability.
* Voiding cystometrogram (pressure-flow study)
*
o Pressure-flow study simultaneously records the voiding detrusor pressure and the rate of urinary flow. This is the only test able to assess bladder contractility and the extent of a bladder outlet obstruction.
o Pressure-flow studies can be combined with voiding cystogram and videourodynamic study for complicated cases of incontinence.
* Cystogram
*
o A static cystogram (anteroposterior and lateral) helps to confirm the presence of stress incontinence, the degree of urethral motion, and the presence of a cystocele. Intrinsic sphincter deficiency will be evident by an open bladder neck. Presence of a vesicovaginal fistula or bladder diverticulum also may be noted.
o A voiding cystogram can assess bladder neck and urethral function (internal and external sphincter) during filling and voiding phases. A voiding cystogram can identify a urethral diverticulum, urethral obstruction, and vesicoureteral reflux.
* Electromyography
*
o Electromyography (EMG) helps to ascertain the presence of coordinated or uncoordinated voiding. Failure of urethral relaxation during bladder contraction results in uncoordinated voiding (detrusor sphincter dyssynergia).
o EMG allows accurate diagnosis of detrusor sphincter dyssynergia common in spinal cord injuries.
* Cystoscopy
*
o The precise role of cystoscopy in the evaluation of neurogenic bladder allows discovery of bladder lesions (eg, bladder cancer, bladder stone) that would remain undiagnosed by urodynamics alone.
o General agreement is that cystoscopy is indicated for people complaining of persistent irritative voiding symptoms or hematuria. The physician can diagnose obvious causes of bladder overactivity, such as cystitis, stone, and tumor, easily. This information is important in determining the etiology of the incontinence and may influence treatment decisions.
* Videourodynamics
*
o Videourodynamics is the criterion standard for evaluation of a patient with incontinence. Videourodynamics combines the radiographic findings of voiding cystourethrogram (VCUG) and multichannel urodynamics.
o Videourodynamics enables documentation of lower urinary tract anatomy, such as vesicoureteral reflux and bladder diverticulum, as well as the functional pressure-flow relationship between the bladder and the urethra.


TREATMENT

Medical care

* Stress incontinence may be treated with surgical and nonsurgical means.
* Urge incontinence may be treated with behavioral modification or with bladder-relaxing agents.
* Mixed incontinence may require medications as well as surgery.
* Overflow incontinence may be treated with some type of catheter regimen.
* Functional incontinence may be resolved by treating the underlying cause, such as urinary tract infection, constipation, or by simply changing a few medications.
* Do not consider anti-incontinence products to be a cure-all for urinary incontinence; however, judicious use of pads and devices to contain urine loss and maintain skin integrity are extremely useful in selected cases. Absorbent pads and internal and external collecting devices have an important role in the management of chronic incontinence. The criteria for use of these products are fairly straightforward, and they are beneficial for women who meet the following conditions: (1) women who fail all other treatments and remain incontinent, (2) women who are too ill or disabled to participate in behavioral programs, (3) women who cannot be helped by medications, (4) women with incontinence disorders that cannot be corrected by surgery, and (5) women who are awaiting surgery.
* Absorbent products
*
o Absorbent products are pads or garments designed to absorb urine to protect the skin and clothing. Available in both disposable and reusable forms, they are a temporary means of keeping the patient dry until a more permanent solution becomes available. By reducing wetness and odor, they help maintain the patient's comfort and allow her to function in normal activities. They may be used temporarily until a definitive treatment takes effect or if the treatment yields less-than-perfect results. Absorbent products are helpful during the initial assessment and workup of urinary incontinence. As an adjunct to behavioral and pharmacologic therapies, they play an important role in the care of persons with intractable incontinence.
o Do not use absorbent products instead of definitive interventions to decrease or eliminate urinary incontinence. Early dependency on absorbent pads may be a deterrent to achieving continence, providing the wearer a false sense of security. Chronic use of absorbent products may lead to inevitable acceptance of the incontinence condition, which removes the motivation to seek evaluation and treatment. In addition, improper use of absorbent products may contribute to skin breakdown and urinary tract infections. Thus, appropriate use, meticulous care, and frequent pad or garment changes are needed when absorbent products are used.
o Absorbent products used include underpads, pant liners (shields and guards), adult diapers (briefs), a variety of washable pants and disposable pad systems, or combinations of these products. More than 50% of members in Help for Incontinent People (HIP) use some form of protective garment to remain dry. In addition, 47% of elderly men and women use some type of absorbent product. In nursing homes, disposable diapers or reusable pad and pant systems are used.
o Unlike sanitary napkins, these absorbent products are specially designed to trap urine, minimize odor, and keep the patient dry. Different types of products with varying degrees of absorbency exist. These products may absorb 20-300 mL, depending on the brand and the absorbent material of the product. Absorbent pads and garments that are available include panty shields, pant guards, undergarments, combination pad-pant systems, adult diaper garments, and special bed pads.
o
+ For occasional minimal urine loss, panty shields (small absorbent inserts) may be used.
+ For light incontinence, guards (close-fitting pads) may be more appropriate. Absorbent guards are attached to the underwear and can be worn under normal clothing.
+ Adult undergarments (full-length pads) are bulkier and more absorbent than guards. They may be held in place by waist straps or snug underwear. Adult briefs are the bulkiest type of protection, offering the highest level of absorbency, and are secured in place with self-adhesive tape.
+ Absorbent bed pads also are available to protect the bed sheets and mattresses at night. They are available in different sizes and absorbencies.
* Urethral occlusive devices
*
o Urethral occlusive devices are artificial devices that may be inserted into the urethra or placed over the urethral meatus to prevent urinary leakage. These devices are palliative measures to prevent involuntary urine loss. Urethral occlusive devices are more attractive than absorbent pads because they tend to keep the patient drier; however, they may be more difficult and expensive to use than pads. Urethral occlusive devices must be removed after several hours or after each voiding.
o Unlike pads, these devices may be more difficult to change. With device manipulation, patients may soil their hands. The risk that a urethral plug may fall into the bladder or fall off the urethra always exists. Urethral occlusive devices, perhaps, are best suited for an active woman with incontinence who does not desire surgery.
* Catheters
*
o Urinary diversion, using various catheters, has been one of the mainstays of anti-incontinence therapy. The use of catheters for bladder drainage has withstood the test of time. Bladder catheterization may be a temporary measure or a permanent solution for urinary incontinence. Different types of bladder catheterization include indwelling urethral catheters, suprapubic tubes, and self-intermittent catheterization.
o Indwelling urethral catheters
o
+ Commonly known as Foley catheters, indwelling urethral catheters historically have been the mainstay of treatment for bladder dysfunction. If urethral catheters are used for a long-term condition, they must be changed monthly. These catheters may be changed at an office, a clinic, or at home by a visiting nurse. The standard catheter size for treating urinary retention is 16F or 18F, with a 5-mL balloon filled with 10 mL of sterile water. Larger catheters (eg, 22F, 24F) with bigger balloons are used for treating grossly bloody urine found in other urologic conditions or diseases. Proper management of indwelling urethral catheters varies per individual.
+ The usual practice is to change indwelling catheters once every month. The catheter and bag are replaced on a monthly basis; however, catheters that develop encrustations and problems with urine drainage must be changed more frequently. All indwelling catheters in the urinary bladder for more than 2 weeks become colonized with bacteria. Bacterial colonization does not mean the patient has clinical bladder infection. Symptoms of bladder infection include foul odor, purulent urine, and hematuria. Fever with flank pain often is present if upper tracts are involved. If bladder infection occurs, change the entire catheter and the drainage system. The urinary drainage bag does not need to be disinfected to prevent infection.
+ Routine irrigation of catheters is not required. However, some authors favor the use of 0.25% acetic acid irrigation because it is bacteriostatic, minimizes catheter encrustation, and diminishes the odor. When used, 30 mL is instilled into the bladder and allowed to freely drain on a twice daily basis.
+ Patients do not have to take continuous antibiotics while using the catheter. In fact, continuous antibiotic therapy is contraindicated while a catheter is used. Prolonged use of antibiotics to prevent infection actually may cause paradoxical generation of bacteria that are resistant to common antibiotics. Indwelling use of a Foley catheter in individuals who are homebound requires close supervision by a visiting nurse and additional personal hygiene care.
+ In spite of its apparent advantages, the use of a Foley catheter for a prolonged period of time (eg, months to years) is strongly discouraged. Chronic dependence on these catheters is extremely risky because long-term use of urethral catheters poses significant health hazards. Indwelling urethral catheters are a significant cause of urinary tract infections that involve the urethra, bladder, and kidneys. Within 2-4 weeks after catheter insertion, bacteria will be present in the bladder of most women. Asymptomatic bacterial colonization is common and does not pose a health hazard. However, untreated symptomatic urinary tract infectionsmay lead to urosepsis and death. The death rate of nursing home residents with urethral catheters has been found to be 3 times higher than that of residents without catheters; this may be more a reflection of the severity of comorbid conditions that lead to the clinical decision to use chronic bladder drainage than causation from the use of chronic bladder drainage.
+ The use of a urethral catheter is contraindicated in the treatment of urge incontinence. Other problems associated with indwelling urethral catheters include encrustation of the catheter, bladder spasms resulting in urinary leakage, hematuria, and urethritis. More severe complications include formation of bladder stones, development of periurethral abscess, renal damage, and urethral erosion.
+ Another problem of long-term catheterization is bladder contracture, which occurs with urethral catheters as well as suprapubic tubes. Anticholinergic therapy and intermittent clamping of the catheter in combination have been reported to be beneficial for preserving the bladder integrity with long-term catheter use. Individuals who did not use the medication and daily clamping regimen experienced a decrease in bladder capacity and vesicoureteral reflux. For this reason, some physicians recommend using anticholinergic medications with intermittent clamping of the catheter if lower urinary tract reconstruction is anticipated in the future.
+ Restrict the use of indwelling catheters to the following situations: (1) as comfort measures for the terminally ill, (2) to avoid contamination or to promote healing of severe pressure sores, (3) in case of inoperable urethral obstruction that prevents bladder emptying, (4) in individuals who are severely impaired and for whom alternative interventions are not an option, (5) when an individual lives alone and a caregiver is unavailable to provide other supportive measures, (6) for acutely ill persons in whom accurate fluid balance must be monitored, and (7) for severely impaired persons for whom bed and clothing changes are painful or disruptive. However, when long-term use of a urethral catheter is anticipated, a suprapubic catheter is an attractive alternative.
o Suprapubic catheters
o
+ A suprapubic tube is an attractive alternative to long-term urethral catheter use. The most common use of a suprapubic catheter is in individuals with spinal cord injuries and a malfunctioning bladder. Both people who are paraplegic and people who are quadriplegic have benefited from this form of urinary diversion. When suprapubic tubes are needed, usually smaller (eg, 14F, 16F) catheters are placed. Like the urethral catheter, change the suprapubic tube once a month on a regular basis.
+ Suprapubic catheters have many advantages. With a suprapubic catheter, the risk of urethral damage is eliminated. Multiple voiding trials may be performed without having to remove the catheter. Because the catheter comes out of the lower abdomen rather than the vaginal area, a suprapubic tube is more patient-friendly. Bladder spasms occur less often because the suprapubic catheter does not irritate the trigone as does the urethral catheter. In addition, suprapubic tubes are more sanitary for the individual, and bladder infections are minimized because the tube is away from the perineum.
+ Suprapubic catheters are changed easily by either a nurse or a doctor. Unlike the urethral catheter, a suprapubic tube is less likely to become dislodged because the exit site is so small. When the tube is removed, the hole in the abdomen quickly seals itself within 1-2 days.
+ Indications for suprapubic catheters include short-term use following gynecologic, urologic, and other types of surgery. Suprapubic catheters may be used whenever the clinical situation requires the use of a bladder drainage device; however, suprapubic catheters are contraindicated in persons with chronic unstable bladders or intrinsic sphincter deficiency because involuntary urine loss is not prevented. A suprapubic tube does not prevent bladder spasms from occurring in unstable bladders nor does it improve the urethral closure mechanism in an incompetent urethra.
+ Potential complications with chronic suprapubic catheterization are similar to those associated with indwelling urethral catheters, including leakage around the catheter, bladder stone formation, urinary tract infection, and catheter obstruction. During the initial placement of a suprapubic tube, a potential for bowel injury exists. Although uncommon, bowel perforation is known to occur with first-time placement of suprapubic tubes. Other potential complications include cellulitis around the tube site and hematoma. If the suprapubic tube falls out inadvertently, the exit hole of the tube will seal up and close quickly within 24 hours if the tube is not replaced with a new one. If tube dislodgment is recognized promptly, a new tube can be reinserted quickly and painlessly as long as the tube site remains patent.
+ A suprapubic catheter is an alternative solution to an indwelling urethral catheter in women who require chronic bladder drainage. Potential problems unique to suprapubic catheters include skin infection, hematoma, bowel injury, and problems with catheter reinsertion. Long-term management of a suprapubic tube also may be problematic if the health care provider lacks the knowledge and expertise of suprapubic catheters or if the homebound individual lacks quick access to a medical center in case of an emergency. In the appropriate situation, the suprapubic catheter affords many advantages over long-term urethral catheters.
o Intermittent catheterization
o
+ Intermittent catheterization or self-catheterization is a mode of draining the bladder at timed intervals, as opposed to continuous bladder drainage. A prerequisite for self-catheterization is the patients' ability to use their hands and arms; however, in a situation in which a patient is physically or mentally impaired, a caregiver or health professional can perform intermittent catheterization for the patient. Of all 3 possible options (ie, urethral catheter, suprapubic tube, intermittent catheterization), intermittent catheterization is the best solution for bladder decompression of a motivated individual who is not physically handicapped or mentally impaired.
+ Many studies of young individuals with spinal cord injuries have shown that intermittent catheterization is preferable to indwelling catheters (ie, urethral catheter, suprapubic tube) for both men and women. Intermittent catheterization has become a healthy alternative to indwelling catheters for individuals with chronic urinary retention due to an obstructed bladder, a weak bladder, or a nonfunctioning bladder. Young children with myelomeningocele have benefited from the use of intermittent catheterization. In addition, self-catheterization is recommended by some surgeons for women during the acute healing process after anti-incontinence surgery.
+ Intermittent catheterization may be performed using a soft, red, rubber catheter or a short, rigid, plastic catheter. The use of plastic catheters is preferable to red rubber catheters because they are easier to clean and last longer.
+ The bladder must be drained on a regular basis, either based on a timed interval (eg, on awakening, every 3-6 hours during the day, and before bed) or based on bladder volume. Remember that the average adult bladder holds approximately 400-500 mL of urine. Ideally, the amount drained each time should not exceed 400-500 mL. This drainage limit may require decreasing the fluid intake or increasing the frequency of catheterizations. If catheterization is performed every 6 hours and the amount drained is 700 mL, increase the frequency of catheterization to, perhaps, every 4 hours to maintain the volume drained at 400-500 mL.
+ Intermittent catheterization is designed to simulate normal voiding. Usually, the average adult empties the bladder 4-5 times a day. Thus, catheterization should occur 4-5 times a day; however, individual catheterization schedules may vary, depending on the amount of fluid taken in during the day.
+ Candidates for intermittent catheterization must have motivation and intact physical and cognitive abilities. Anyone who has good use of her hands and arms can perform self-catheterization. Young children and the older population are able to do this everyday without problems. For individuals who are impaired, a home caregiver or a visiting nurse can be instructed to perform intermittent catheterization. Self-catheterization may be performed at home, at workÛanywhere.
+ Intermittent catheterization may be performed using either a sterile catheter or a nonsterile clean catheter. Intermittent catheterization, using a clean technique, is recommended for young individuals with a bladder that cannot empty and without any other available options. Patients should wash their hands with soap and water. Sterile gloves are not necessary. Clean intermittent catheterization results in lower rates of infection than the rates noted with indwelling catheters.
+ Studies show that in patients with spinal cord injuries, the incidence of bacteria in the bladder is 1-3% per catheterization and 1-4 episodes of bacteriuria occur per 100 days of intermittent catheterization performed 4 times a day. Furthermore, the infections that do occur usually are managed without complications. In general, routine use of long-term suppressive therapy with antibiotics in patients with chronic clean intermittent catheterization is not recommended. The use of chronic suppressive antibiotic therapy in people regularly using clean intermittent catheterization is undesirable because it may result in the emergence of resistant bacterial strains. In high-risk populations, such as patients with an internal prosthesis (eg, artificial heart valve, artificial hip) or patients who are immunosuppressed because of age or disease, determine whether to use antibiotic therapy for asymptomatic bacteriuria on individual merits.
+ For the older population and individuals with a weak immune system, the sterile technique of intermittent catheterization has been recommended. Persons who are older are at higher risk than younger persons for developing bacteriuria and other complications caused by intermittent catheterization because they do not have a strong defense system against infection. Although the incidence of infection and other complications for older patients who are using sterile versus clean intermittent catheterization is not well established, sterile intermittent catheterization appears to be the safest method for this high-risk population.
+ Potential advantages of performing intermittent catheterization include patient autonomy, freedom from indwelling catheter and bags, and unimpeded sexual relations. Potential complications of intermittent catheterization include bladder infection, urethral trauma, urethral inflammation, and stricture. Concurrent use of anticholinergic therapy will maintain acceptable intravesical pressures and prevent bladder contracture. Studies have demonstrated that long-term use of intermittent catheterization appears to be preferable to indwelling catheterization (ie, urethral catheter, suprapubic tube) with respect to urinary tract infections and the development of stones within the bladder or kidneys.

Surgical care

* Surgical care for stress incontinence involves procedures that increase urethral outlet resistance. Operations that increase urethral resistance include bladder neck suspension, periurethral bulking therapy, sling procedures, and artificial urinary sphincter.
* Surgical care for urge incontinence involves procedures that improve bladder compliance or bladder capacity; these include sacral neuromodulation, botulinum toxin injections, detrusor myomectomy, and bladder augmentation.

Diet

The fact that certain foods in a daily diet can worsen symptoms of urinary frequency and urge incontinence is well known. If a patient's diet contains dietary stimulants, changes in her diet may help ameliorate incontinence symptoms. Dietary stimulants are substances contained in the food or drink that either cause or exacerbate irritative voiding symptoms. By eliminating or minimizing the intake of dietary stimulants, unwanted bladder symptoms can be improved or possibly cured. Avoidance of dietary stimulants begins with consumer awareness through careful label reading and maintaining a daily diet diary. Experimenting with dietary changes is not appropriate for everyone, and dietary experimentation should be instituted on an individual basis. Certain food products exacerbate symptoms of urge incontinence.

* Food
*
o Foods that contain heavy or hot spices may contribute to urge incontinence. A few medical reports have alluded to the fact that avoiding spicy foods may have a beneficial effect on urinary incontinence. Some examples of hot spices include curry, chili pepper, cayenne pepper, and dry mustard.
o A second food group that may worsen irritative voiding symptoms is citrus fruit. Fruits and juices that have a high potassium concentration may worsen preexisting urge incontinence. Examples of fruits that have significant potassium include grapefruits and oranges.
o A third food group that may worsen urinary bladder incontinence is chocolate-containing sweets. Chocolate snacks and treats contain caffeine. Caffeine is a bladder-unfriendly agent. Excessive intake of chocolate confectioneries worsens irritative bladder symptoms.
* Beverages
*
o The quantity and quality of refreshments consumed will influence urinary voiding symptoms. An average American adult requires a daily allowance of approximately 6-8 glasses of fluids. Fluids refer to all the beverages a person consumes in a day, including water, soda, and milk. The human body receives water from beverages consumed, water contained in the food ingested, and water metabolized from food eaten. The recommended amount of fluids consumed (all types) in 24 hours totals 6-8 glasses. The benefits of adequate fluid intake include prevention of dehydration, constipation, urinary tract infection, and kidney stone formation.
o Some patients tend to drink water excessively. Some women drink water because they enjoy the taste. Others take medication that makes their mouths dry, so they drink more water. Some women who are trying to lose weight are on a diet that requires consuming abundant amounts of water. Drinking water excessively actually worsens irritative bladder symptoms. The exact amount of fluid needed per day is calculated based on the patient's lean body mass. Thus, the amount of fluid requirement will vary per individual.
o Some older women do not drink enough fluids to keep themselves well hydrated. They minimize their fluid intake to unacceptable levels, thinking that if they drink less, they will experience less incontinence. Trying to prevent incontinence by restricting fluids excessively may lead to bladder irritation and actually worsen urge incontinence. In addition, dehydration contributes to constipation. If a patient has a problem with constipation, recommend eating a high-fiber diet, receiving adequate hydration, and administering laxatives.
o Many drinks contain caffeine. Caffeine is a natural diuretic, and it has a direct excitatory effect on bladder smooth muscle. Thus, caffeine-containing products produce excessive urine and exacerbate symptoms of urinary frequency and urgency. Caffeine-containing products include coffee, tea, hot chocolate, and sodas. Even chocolate milk and many over-the-counter medications contain caffeine. Of caffeine-containing products, coffee contains the most caffeine. Drip coffee contains the most caffeine, followed by percolated coffee and then instant coffee. Even decaffeinated coffee contains a small amount of caffeine. Decaffeinated coffee contains an amount of caffeine similar to the amount in chocolate milk. Persons who consume a large amount of caffeine should slowly decrease the amount of caffeine consumed to avoid significant withdrawal responses such as headache and depression.
o Studies have shown that drinking