URODYNAMIC STUDIES
Prepared by : Pooja Aryal
Bsc.Nursing 2nd year
15th batch
Chitwan Medical College
General Objectives:
• At the end of the session, B.Sc Nursing 2nd Year students will be
able to explain about urodynamic studies.
Specific Objectives:
At the end of the session, B.Sc Nursing 2nd year students will be able to
explain about :
introduction of urodynamic studies
indications of urodynamic studies
contraindications of urodynamic studies
components of urodynamic studies
URODYNAMIC STUDIES
• Urodynamic studies are group of tests that evaluate how the
bladder, urethra, and sphincter muscles are working to store and
release urine.
INDICATIONS
1. Lower Urinary Tract Symptoms (LUTS)
• Difficulty in voiding (obstructive symptoms such as weak stream
or straining).
• Storage symptoms (urgency, frequency, or nocturia).
• Urge or stress urinary incontinence.
2. Neurogenic Bladder Dysfunction
Conditions like spinal cord injury, multiple sclerosis, Parkinson's disease, or
diabetes with suspected bladder involvement.
• Assessing bladder compliance and capacity to prevent kidney damage.
3. Overactive Bladder (OAB)
• Persistent urinary urgency and frequency with or without
urge incontinence not responding to initial treatments.
4. Post-Prostate Surgery Complications
• Persistent or recurrent symptoms after procedures like
transurethral resection of the prostate (TURP) or radical
prostatectomy.
5. Suspected Outlet Obstruction
• Symptoms suggestive of bladder outlet obstruction in both men
and women.
6. Recurrent Urinary Tract Infections (UTIs)
• In cases where an anatomic or functional abnormality is suspected as
a contributing factor.
7. Pelvic Organ Prolapse
• To evaluate the functional impact of prolapse on the bladder
and urethra.
8. Preoperative Assessment
• For complex surgeries like incontinence procedures or
pelvic reconstructive surgery.
9. Pediatric Conditions
• Enuresis (bedwetting), vesicoureteral reflux, or dysfunctional
voiding in children.
ABSOLUTE CONTRAINDICATIONS
Active Urinary Tract Infection (UTI):
• Performing UDS during an active UTI increases the risk of complications such as worsening
infection or urosepsis.
• The procedure should be delayed until the infection is treated with antibiotics.
Severe Hematuria:
• Visible blood in the urine may interfere with test accuracy and increase the risk of infection.
Bladder or Urethral Trauma:
• Recent trauma or surgery involving the lower urinary tract can complicate the test
and exacerbate the injury.
Severe Obstruction or Retention:
• Patients with high residual volumes or complete obstruction may not tolerate the procedure.
RELATIVE CONTRAINDICATIONS
Pregnancy:
• UDS is typically avoided during pregnancy unless absolutely necessary due to
potential risks to the fetus.
Recent Surgery:
• Recent lower urinary tract or pelvic surgery can interfere with the test's accuracy
and healing process. A waiting period is usually recommended.
Anticoagulation Therapy:
• Patients on blood thinners have a higher risk of bleeding or hematoma
formation during catheter insertion.
Severe Cardiorespiratory Conditions:
• Patients with unstable conditions (e.g., severe heart failure or uncontrolled
hypertension) may not tolerate the stress of the procedure.
COMPONENTS OF URODYNAMIC
STUDIES
• Uroflowmetry
• Cystometry (Cystometrogrm-CGM)
• Pressure flow study
• Electromyography (EMG)
• Urethral Pressure Profilometry (UPP)
• Video urodynamics
• Post Void Residual (PVR) Measurement
URINE FLOW STUDY (UROFLOWMETRY)
Uroflowmetry is a diagonastic test used
to measure the rate of urine flow
during urination.
It helps to access how well the
bladder and urethra are functioning.
In this test the patient is asked to drink
fluids(4 glasses) normarlly before the
test but to avoid emptying their
bladder for a certain period before the
test. An average 250 cc urine should
be extracted for the test.
Contd….
The patient is asked to urinate into a special toilet or urinal that contains
a flowmeter.
This device measure the rate of urine flow and records it on a graph
or computer.
The flow of urine is typically measured in milliliter per seconds (ml/s) or
in milliliter per minutes(ml/m).
The test may also record other parameters such as ; the total volume of
urine voided and the time it takes to empty the bladder completely.
The result of the uroflowmetry test are analyzed by a health care provider
to access the pattern of urine flow and identify any abnormalities such as
obstruction or weak bladder contraction.
Contd..
What are the normal values of uroflowmetry in children?
When necessary, uroflowmetry test is also requested in children. The
average values for boys and girls are as follows by age;
• Average flow rate between 4-7 years old is 10 ml/sec.
• Mean flow rate 12 ml/sec in boys aged 8-13 years
• Mean flow rate in girls aged 8-13 years is 15 ml/sec.
What are the normal values of the uroflowmetry test in men?
In men, uroflowmetry values change with age. In aging men, the
urinary flow rate slows down due to prostate enlargement. In addition,
uroflow test results are also low, as bladder contractions will weaken
as a natural result of aging and due to reasons such as diabetes.
Normal uroflowmetry values in men are as follows according to age;
• Mean flow rate in men aged 14-45: 21 ml/s
• Average flow rate in men aged 46-65: 12 ml/s
• Mean flow rate in men aged 66-80: 9 ml/s
What are the normal values of the uroflowmetry test in women?
Unlike men, uroflowmetry results are not affected much by age in
women. Generally, uroflow tests in women remain the same.
• Average flow rate in women aged 14-45: 18 ml/s
• Average flow rate in women aged 46-65: 18 ml/s
• Average flow rate in women aged 66-80: 18 ml/s
Interpretation of the uroflowmetry test
• Uroflowmetry is used to evaluate the urinary flow rate due to an obstruction in
the urinary tract after the bladder or BPH. We can estimate the degree of
obstruction (occlusion, stenosis) according to the maximum flow. According to
this;
• If the maximum flow rate is above 20 ml/s, there is no possibility of an obstruction.
• If the maximum flow rate is between 15-20 ml/sec, there is a low probability
of obstruction. If there is clinical suspicion, it should be investigated.
• If the maximum flow rate is between 10-15 ml/sec, obstruction is suspected.
• If the maximum flow rate is less than 10 ml/sec, there is severe obstruction or
impaired bladder contractions.
• The total amount of urine made is also important for a healthy interpretation. If this
amount is less than 100 ml, the results should be viewed with suspicion and
repeated.
POST VOID RESIDUAL MEASUREMENT
• When using the restroom, it is expected
that the bladder will fully empty. However,
there are instances where urine remains in
the bladder even after the sensation of
having completed urination. The volume of
urine that remains post-urination is referred
to as post-void residual (PVR). While a small
residual volume is considered normal,
significant amounts—known as urinary
retention—may indicate underlying health
issues that require medical attention.
What is the PVR test used for?
• Frequent urination.
• Urine leakage (incontinence).
• Frequent urinary tract infections (UTI).
• Bladder stones.
Methods of PVR:
1. Ultrasound (bladder scan)
A non invasive method that uses sound waves to estimate bladder
volume.
2. Catheterization
A sterile catheter is inserted into the urethra to drain residual urine.
VIDEO URODYNAMICS
• Video urodynamics is an advanced diagnostic procedure that combines
traditional urodynamic testing with imaging techniques such as
fluoroscopy or ultrasound.
• The patient will be asked to empty their bladder before the test
begins. They may also need to change into a gown.
• A thin catheter is inserted into the bladder through the urethra to
measure bladder pressure and collect urine.
• Fluoroscopy or ultrasound is used to visualize the bladder and urethra
in real-time as the bladder fills and empties. This allows the healthcare
provider to see any abnormalities or dysfunction in the urinary tract.
• The bladder is slowly filled with a sterile saline solution through the
catheter while the patient is monitored. The patient may be asked
to report sensations such as urgency or discomfort.
• The patient will be instructed to empty their bladder while imaging
continues. This helps assess bladder emptying and the coordination
of bladder and urethral function.
• The data collected from the pressure measurements and imaging
is analyzed to evaluate bladder function, urethral function, and the
presence of any abnormalities or conditions such as urinary
incontinence or bladder obstruction.
• Video urodynamics provides a comprehensive assessment of the
lower urinary tract and is particularly useful for diagnosing
complex urinary disorders or evaluating treatment outcomes.
ELECTROMYOGRAPHY
• In urodynamic studies, electromyography (EMG) is typically performed
by placing small electrodes on or near the pelvic floor muscles.
• These electrodes detect the electrical signals generated by muscle activity.
• During the test, the patient may be asked to perform tasks such
as voluntary pelvic floor contractions, relaxation, or bearing
down.
• The EMG signals are recorded and analyzed to assess the coordination
and strength of the pelvic floor muscles during various bladder activities,
such as filling and voiding. This information helps in diagnosing conditions
related to pelvic floor dysfunction and urinary incontinence.
PRESSURE FLOW STUDY
• Pressure flow studies, also known as pressure-flow urodynamic
studies, are diagnostic tests used to evaluate bladder and urethral
function during urination.
• These tests are particularly useful for diagnosing conditions such
as bladder outlet obstruction.
• In this ,Similar to cystometry, thin catheters are inserted into the
bladder through the urethra. One catheter measures bladder
pressure, while another measures pressure in the urethra.
• The bladder is slowly filled with sterile water or saline solution while
pressure sensors measure bladder pressure. The patient may be
asked to report sensations such as the first urge to urinate or when
they feel their bladder is full.
• Once the bladder is sufficiently full, the patient is asked to urinate.
During urination, pressure measurements are taken simultaneously
from the bladder and urethra to assess the flow of urine and the
pressure exerted by the bladder and urethra.
• The pressure and flow data obtained during the study are analyzed to
determine parameters such as maximum flow rate, detrusor pressure
at maximum flow, and the presence of obstruction or other
abnormalities in bladder and urethral function.
• Pressure flow studies provide valuable information about bladder and
urethral function and can help diagnose conditions such as bladder
outlet obstruction or detrusor sphincter dyssynergia. The procedure is
typically performed in a clinic or hospital setting by a trained
healthcare professional.
CYSTOMETRY
It is a test which measures the pressure inside the
urinary bladder when it is filled with fluid.
This test help assess bladder function and identify
any abnormalities causing urinary symptoms.
In this test ,first of all, patient is made to empty the
bladder.
Then, a catheter is inserted into bladder through
urethra which is connected to a machine that
measures pressure.
The bladder is then filled with sterile fluid .
• As the bladder is filled , the patient may be asked to cough or
bear down to test bladder function under stress.
• Once the bladder is full, the patient may ask to urinate while
pressure measurements are taken
• The entire procedure takes about 30- 35 minutes.
URETHRAL PRESSURE PROFILOMETRY
• A urethral pressure profile is a diagnostic test used in
urodynamic studies to assess the pressure within the urethra
(the tube that carries urine from the bladder out of the body) at
rest and during various activities, such as coughing or straining.
• During the test, a small catheter with pressure sensors is
inserted into the urethra.
• The catheter is slowly withdrawn while pressure measurements
are recorded at different points along the length of the urethra.
• This allows the healthcare provider to create a profile of
urethral pressure under different conditions.
• Urethral pressure profile testing helps diagnose conditions such as
urethral sphincter dysfunction or urinary incontinence by
evaluating the ability of the urethra to maintain pressure and
prevent urine leakage.
References:
Black, J.M., & Hinkle, J.L. (2009). Medical Surgical Nursing; (8th ed.).
volume-2 Reed Elsevier India Pvt. Ltd.
Lewis, S.L, Dirksen, S.R, Heitkemper, M.N., & Bucher, L., (2014).
Lewi’s Medical Surgical Nursing(3rd ed.). Harayana, India: Reed
Elsevier Pvt. Ltd.
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