( Notes for Medical/Postgraduate students)
1. Introduction
Evaluation of female urinary incontinence in these guidelines is aimed at establishing whether the patient has genuine incontinence, urge incontinence or overflow incontinence. Although there is need to introduce some form of cystometric studies, resources are limited in many hospitals. There is a need to triage patients using a primary care approach so as to enable gynaecologist to establish a diagnosis early.
Urodynamic is the study of the physiological relationship between the bladder and urethra. The bladder and urethra behave as a reciprocal functional unit requiring neuromuscular coordination to promote micturition. Two basic aims of urodynamic studies are to reproduce the patient’s urinary symptoms and to explain the pathophysiological basis of the patient’s lower urinary tract dysfunction.
Urinary tract infection must be ruled out before initiating further investigations or therapeutic interventions. Treating urinary tract infection will result in resolution of symptoms, thus avoiding unnecessary investigations and treatment. A clinical history is sufficient to distinguish satisfactorily between genuine stress incontinence (GSI) and detrusor instability (DI). The only reliable means of detecting DI is the cystometry.
2. The normal micturition cycle
Three phases :
· Filling and storage
· Initiation
· Voiding
2.1 Filling and storage phase
The bladder normally fills with urine by a series of peristaltic, ureteric contraction at a rate of between 0.5 and 5 ml/min. Under these conditions the bladder pressure increases only minimally. Urethral closure is maintained by the combined passive and active effects of its smooth and striated muscle components, its elastic content, and its blood supply.
During the early stages of bladder filling, proprioceptive afferent impulses from stretch receptors within the bladder wall pass via the pelvic nerves to sacral dorsal roots S2 – S4. These impulses ascend in the cord via the lateral spinothalamic tracts and a detrusor motor response is subconsciously inhibited by descending impulses from the subcortical micturition centres.
As the bladder volume increases, further afferent impulses ascend to the cerebral cortex, and the sensation of bladder filling associated with the desire to micturate is first consciously appreciated (first sensation), usually at between 200 and 300 ml (half the functional bladder capacity).
The inhibition of detrusor contraction is now cortically mediated, although the desire to void may be further suppressed to subconscious levels again. With further filling, impulses within the visceral afferent fibres accompanying the sympathetic efferents to thoracolumbar roots T10 to L2 ascend to the cerebral cortex, and a further desire to void is appreciated. During this time, in addition to the cortical suppression of detrusor activity, there may also be a voluntary pelvic floor contraction in an attempt to maintain urethral closure.
2.2 Initiation phase
When a suitable time, site and posture for micturition are selected, the process of voiding commences. Relaxation of the pelvic floor occurs simultaneously with the relaxation of the intrinsic striated muscle, causing a marked fall in intra-urethral pressure.
A few seconds later the descending inhibitory influences from the cerebral cortex acting on the sacral micturition centre are suppressed, allowing a rapid discharge of efferent parasympathetic impulses via the pelvic nerves, to cause contraction of the detrusor. When the falling urethral and increasing intravesical pressure equate, urine flow will commence.
2.3 Voiding phase
At the initiation of micturition, the bladder takes on a nearly spherical shape. As the mural tension rises in the absence of voiding, the intravesical pressure also rises. When a critical opening pressure is achieved, urine starts to flow and the bladder radius will fall. The pressure, however, usually remains constant during voiding, and the mural tension therefore must fall.
Once initiated, therefore, the process of micturition requires little to sustain it. Whilst active tension is required throughout, the effectiveness of detrusor contraction increases as the muscle fibres shorten and therefore decreasing forces are required as micturition proceeds.
3. Basic mechanisms of incontinence
Three common conditions seen are:
(1) urge incontinence (irritable bladder, hyperactive bladder, overactive bladder)
(2) stress incontinence ( USI)
(3) overflow incontinence ( Voiding dysfunction).
Urge incontinence results from bladder detrusor muscle contractions that overcome the cerebral centre to inhibit them. Common causes include imflammation or irritation of bladder or impairment due to neurological condition. Eg. Stroke, Parkinsons, drugs etc.
Stress incontinence is due to a malfunction of the urethral sphincter causing leaking of urine from bladder when intra-abdominal pressure increases eg. coughing. Genuine stress incontinence (GSI) is caused by pelvic prolapse, urethral hypermobility or displacement of bladder neck from normal anatomic alignment. Instrinsic sphincter deficiency (due to denervation or a congenital state), radiation damage, surgical trauma can also produce GSI.
Overflow incontinence is uncommon and is often due to obstruction to the outlet or due to a neurogenic bladder ( Bladder failure). eg. diabetic neuropathy. Radiation therapy, surgery and tumors may also produce these symptoms.
4. History
4.1 Micturition / urinary habit
4.1.1 Symptoms of storage disorders
· Frequency – number of times per day that the patient voids. More than eight voids per day suggest a problem with frequency, but this is highly dependent upon habit and fluid intake.
· Urge incontinence – urine loss accompanied by a strong desire to urinate (urgency). Urgency may due to unstable detrusor activity (motor urgency), but it also may associated with inflammatory bladder disorders and other causes of sensory urgency. Always exclude lower urinary tract infection.
· Nocturia – awakening from sleep with the need to urinate. If this occurs more than once per night, it may represent an abnormality, although nocturia is highly dependent on patient age and normally increases with advancing age.
· Stress incontinence – urine loss under conditions of increased intra-abdominal pressure. This may be due to urethral and bladder neck incompetence, but urine loss during physical exertion/activity also may be produced by unstable detrusor contractions triggered by movement or changes of position without an accompanying sense of urgency, overdistended bladder too can produce imtermittent urinary leakage.
4.1.2 Symptoms of emptying disorders
· Hesitancy – trouble starting the stream of urine
· Straining to void- need to press to pass urine
· Poor flow-the stream of urine is slow and take considerable time to void
· Intermittent stream-flow of urine is disrupted intermittently
· Postmicturition dribble
· Acute urinary retention - acute urinary retention is manifested as an ability to void that requires catheterization and results in the drainage of large volume of urine. While this may be psychological in origin, it may also represent serious underlying pathology.
Hesitancy, straining to void, and poor or intermittent flow can all reflect either urethral or detrusor dysfunction. Postmicturition dribbling may be a clue to the presence of a urethral diverticulum.
4.1.3 Symptoms of disordered sensation
· Urgency
· Dysuria
· Bladder pain
· Feeling of pressure or prolapse
· Unconscious urine loss
Symptoms of disordered bladder sensation are the most difficult to evaluate, since they are subjective. Urgency, dysuria and bladder pain may all be accompaniment of acute urinary tract infection, inflammatory bladder disorders, such as interstitial cystitis, psychosomatic reactions to stress, or neoplasia. Feeling of “pressure” in the lower pelvis may represent the effects of a large cystocoele or other gynaecologic pathology, such as a large ovarian tumor or uterine leiomyoma. Often such symptoms have no obvious explanation. A lack of bladder sensation or unconscious and unnoticed urine loss is worrisome, as they may represent underlying neurologic disease.
4.1.4 Symptoms of disordered contents
1) Haematuria 2) stones
3) Abnormal colour 4) foreign body
5) Abnormal smell 6) miscellaneous (Chemical or other abnormality)
Such changes may be the result of recent dietary indiscretion or the normal mechanism of urine concentration at work in the kidneys, but they also may represent underlying metabolic disease, infection, or something more sinister such as urinary tract malignancy.
4.2 Gynaecological history
· Menstrual history
· Previous gynaecological surgery, either abdominal or vaginal surgery.
4.3 Obstetric history
· Parity, delivery type, baby’s birth weight
4.4 Surgical history
· Pelvic, spinal surgery
4.5 Medical disorders:
· Diabetes Mellitus
· Myelitis
· Cerebrovascular accident, central nervous system injury / trauma
4.6 Drugs
· Diuretics, anti-cholinergics, anti-depressants
4.7 Social history
· Occupation, alcohol
4.8 Congenital problem
5. Physical examination
· General – obesity, senility, dementia, neurological disorders.
· Patient should come with a full bladder.
5.1 Inspect in lithotomy position
Determine intergrity of sacral nerve roots (viz. Anocutaneous, bulbocavernosus reflexes, sensation to touch using cotton tip, and voluntary contraction of external anal sphincter.
5.2 Perform speculum examination. Determine vaginal epithelial state of oestrogenation.
5.3 Determine pelvic relaxation or prolapse
· Uterine or vault prolapse
· Cystocoele (paravaginal and central supports)
·
· Enterocoele grade + / - or stage of prolapse
· Cough in lithotomy position and determine if there is escape of urine. If absent, repeat this in standing position ( standing cough test).
5.4 Bimanual examination is done
· To exclude pelvic masses
· To assess contraction of pelvic floor muscles by palpating vaginal side wall.
· We can also access pelvic floor muscle strength and teach patients how to do pelvic floor exercises.
5.5 Assessment of urethrovesical junction mobility using Q-tip test or transvaginal
ultrasound is done as described below as volumetric-cystometric tests are done.
6. Urinalysis
Urine microscopy and further investigations like urine culture and blood sugar level are diagnostic. Urinary tract infections and diabetes need exclusion.
7. Frequency / volume chart
Frequency / volume chart gives an idea of the patient’s daily fluid intake and voiding habits. It is a simple, cheap, non invasive and objective method of detecting and quantifying urinary leakage.
Day | Time / volume (mls) Day-time | Night-time |
1 | 6.30 am 10 am 12 noon 100 work | 1.0 am 150 |
2 | ||
3 | ||
4 | ||
5 | ||
6 | ||
7 |
8. One hour Pad weighing test
This test is designed to quantify urine loss under standard and reproducible conditions. Having emptied her bladder, the patient wears a pre-weighed absorbent nappy or pad, drinks 500 ml of liquid over a 15 minute period, then performs a series of tasks including walking, climbing stairs, coughing, and hand washing, over a 60 minute period.
The pad is then re-weighed and the urine loss recorded in grams. The increase in weight
of the pad is an indication of urine loss. A gain of less than 1 gram is not considered a
sign of incontinence. The pad test is also useful for assessing treatment outcome.
Time Procedure
----------------------------------------------------------------------
15 min Drink 500 ml water, sitting
30 min Walk, walk up staircase
45 min Alternate between sitting and standing, X 10
Jog on the spot for 1 minute
Pick an object up off the floor x5
Remove the pad, weigh it, calculate urine loss. Void, determine the voided volume.
9. Postvoid Residual Urine Volume (PVR)
As part of the basic evaluation of urinary incontinence, all patients should undergo measurement of PVR urine volume to detect urinary retention (i.e, overflow bladder). PVR volume measurement can detect retention caused by potentially reversible factors (e.g, anticholinergic or other drugs, fecal impaction). Urinary retention not obviously resulting from a transient cause generally requires specialized evaluations, to determine why the bladder does not empty properly.
The PVR urine volume can be measured by one of two methods.
(i) “In and out” urethral catheterization within a few minutes after the patient has urinated to empty the bladder.The quantity of urine obtained is noted.
(ii) Pelvic ultrasonography.
Normally, less than 50 ml of residual urine is present after voiding. Volumes of more than 100 to 150 ml are abnormal. The formula for estimating volume: Height x width x depth x 0.5. A significant amount of residual urine indicates abnormal detrusor function and is caused by underactive detrusor function either due to poor bladder contractility or infravesical obstruction. Incomplete emptying is also seen in neurogenic bladder dysfunction.
10. Office Cystometry
Simple office cystometry is a test for urge incontinence. A French non ballooned urinary catheter, (no. 12 to no. 14) is inserted into the bladder. Catheterization can be performed at the same time that PVR urine volume is measured.
After the bladder empties, in a sit up position, the plunger is removed from a bayonet-tipped 50 ml syringe, and the tip is inserted into the end of the catheter. With the physician holding the center of the syringe about 15 cm above the urethra, 50 ml of sterile water is poured into the open end of the syringe and allowed to flow into the bladder. Keeping track of the total amount of water used, the physician continues to instill water in 50 ml increment until the patient experiences the urge to urinate (first urge or sensation).
As this point, water instillation is continued in 25 ml increment until the patient experiences severe urgency (“I can’t hold it anymore”) or bladder contraction occur. Contractions are detected by monitoring the fluid level that appears in the syringe after several aliquots of water have been instilled. A rise and fall in the fluid level indicates pressure changes (i.e, contractions) within the bladder.
Severe urgency or bladder contractions at less than 300 ml of bladder volume constitute a presumptive diagnosis of urge incontinence. For the diagnosis of urge incontinence, simple cystometry has a 75 to 100 percent sensitivity, a 69 to 89 percent specificity, and a 74 to 91 percent positive predictive value, using formal multichannel cystometrography as the gold-standard comparison.
11. Stress test
After office cystometry, evacuate the urine from the bladder, and leave about 100 ml urine in the bladder. The patient lies supine on the examination table and asked to cough forcefully. If the urine leaks during coughing, a presumptive diagnosis of stress incontinence is made.
If no incontinence is demonstrated in the supine position, the maneuvers should be repeated with the patient in a standing position. If no incontinence occurs in either position, the patient probably does not have stress incontinence.This test is then followed by Bonney’s test.
12. Bonney’s test
In case of urine leakage during straining, a Bonney’s test may confirm urethral hypermobility though this test is uniformly acceptable. This is performed by placing the index and middle finger on each side of the urethra at the level of the bladder neck and supporting it with care taken not to cause compression of the urethra against the pubic bone. The patient is asked to cough or strain while the bladder neck is pushed up. If urine leakage is controlled with lifting motion, a positive result, bladder neck descent and urethral hypermobility with laxity in paraurethral support is assumed to be the cause of the incontinence and urethral elevation prevents further urine leakage. We Rarely perform this test this days.
13. Q-tip test
The Q-tip test is an indirect method of diagnosing urethral hypermobility. With the patient in a lithotomy position, a sterile, lubricated cotton tip swab is inserted into the urethra until it lies just within the bladder neck area (around 3 to 4 cm from the meatus). Using a goniometer, the angle circumscribed by the distal end of the swab is measured relative to the horizontal while the women are exerting maximum valsalva effort. An angle of more than 30 degrees is considered significant and diagnostic of urethral hypermobility. We Rarely perform this test this days.
Patient who do not demonstrate hypermobility of the uretro-vesicular junction unlikely to be cured of incontinence after standard surgical procedures.
14. Transvaginal ultrasound
The use of transvaginal probe was advocated in order to observe the opening and descent of the bladder neck. The vaginal probe is inserted to about 1 to 2 cm from the introitus and an immediate bladder neck opening can be seen on straining. However, genuine stress incontinence or detrusor instability are not simply diagnosed because of leaks from the bladder into the proximal urethra. The urine leakage must reach beyond the distal sphincter mechanism or else incontinence cannot be said to occur.
15. Dynamic Cysto-Urethroscopy (DCU)
Dynamic Cysto-Urethroscopy enable direct visualisation of the urethra and its internal sphincter (urethro-vesical junction) at rest, and its response to strain. Furthermore, the bladder wall, trigone and ureterovesicular junction also can be visualised.
16. Equipment
1. Pre-weighed pad
2. Weighing scale
3. Sterile gloves
4. Sterile catheterization set
5. Cotton tip swab (sterile)
6. 50 cc syringe
7. Foley’s catheter size 12 or 14 (with adapter, without balloon)
8. Measuring jug
9. Goniometer
10. Urethroscope
11. Ultrasound machine with transabdominal and vagina probe
APPENDIX 1
CHECK LIST – UROGYNAECOLOGY CLINIC
I/C No :……………………………………..
Date : ……………
LMP :…………….
A. HISTORY
1. BLADDER SYMPTOMS
Intermittent stream....................
dribble...............
Dysuria............
Bladder pain................
Haematuria...................Abnormal Color / smell................ Stone .....................
Bladder pain................
Haematuria...................Abnormal Color / smell................ Stone .....................
11. GYNAECOLOGICAL HISTORY
Specify : ………………………………………………………………………………
111. OBSTETRIC HISTORY
Delivery type SVD....... Episiotomy: YES/No
1V. SURGICAL HISTORY
V. MEDICAL HISTORY
VI. DRUG HISTORY
Others
Specify : ……………………………………………………………………..
VII. SOCIAL HISTORY
Occupation : ……………………………………………………………….
Alcohol consumption [ Y / N ]
B. PHYSICAL EXAMINATION
1. GENERAL
Weight : ………. kg Height : …….cm Body Mass Index (BMI) : ……..
2. ABDOMEN
3. RECTAL EXAMINATION
4. PELVIC EXAMINATION
5. NEUROLOGICAL
Power
Sensation
Reflexes
Anal wink reflex [ Y / N ]
Bulbocavernosus reflex [ Y / N ]
C. URINALYSIS / BLOOD SUGAR LEVEL
UFEME : ………………………….
MSU Culture & Sensitivity :………………………......................
Blood sugar level : ……..mmol / l
D. CURRENT MEDICATION
No | Drugs * | Dose | Frequency | Dur. of use | Subjective Response* |
1---5---10 |
· includes contraceptives
** < 5 = worse 5 = no response > 5 = improved 10 = no symptoms
APPENDIX 11
URODYNAMIC EVALUATION
1. Urine Volume : ………mls
2. Residual Volume : ………..mls (less than 50 mls)
Ultrasound : ……….cm x …….cm x ……..cm x 0.5 = ………….mls
3. Q-tip test : ………degree
4.
5. One hour pad weighing test
Pre-weighed pad : ……..grams
One hour pad weighing test : .. ……grams
6.
7. Office Cystometry
First sensation : ……….mls (150 – 250 mls)
Maximum bladder capasity : ………mls (400 – 600 mls)
Rise and fall of meniscus in the syringe: Present/ Absent
7. Urethroscopy
Morphology :
Description | Bladder Trigone | UV Junction | Proximal urethra | Mid - urethra | Distal urethra |
Red | |||||
Granular | |||||
Shaggy, Fronds | |||||
Polyps | |||||
Cysts | |||||
Exudate | |||||
Diverticulum | |||||
Paleness |
Urethro-vesical junction | Closes | No change | Opens |
Respose to hold | |||
Response to cough | |||
Respose to valsalva |
REFERENCES
1. Weiss BD. Diagnostic Evaluation of urinary incontinence in geriatric patients. American Academy of Family Medicine June 1998; 1-14.
2. Chin CM. Urodynamic Investigations for assessment of bladder dysfunction: Part 1.Medical progress 1999; 26(8): 15-18.
3. Chin CM. Urodynamic investigations: Part 2. Medical progress 1999; 26(9): 15-20.
4. Lapitan MCM. The role of the pelvic floor in urinary incontinence and other urological conditions. Medical progress 1999; 26(10): 27-32.
5. Hilton P. Anatomy and physiology of lower urinary tract and the pathiphysiology of urinary incontinence and sensory disorders of lower urinary tract. Urogynaecology: The investigations and management of urinary incontinence in women 1997; 2: 1-16.
6. Jarvis G. Female urinary incontinence: which patients ? which test ?. Urogynaecology: The investigations and management of urinary incontinence in women 1997; 2: 43-58.
7. Thompson JD, Wall LL, Growdon WA et al. Urinary stress incontinence.Te Linde’s Operative Gynaecology 1992; 7: 887-940.
8. Abrams P, Wein AJ. The Overactive bladder; A widespread and treatable condition 1998; 1: 1–54.
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