Cystometry Dr. Abdelazim Hussein Khalafalla Ass . Professor Urology Department National Ribat University Cystometery Filling cystometry Voiding cystometery Ability to store Efficacy of Emptying Filling Cystometry • Measures the pressure/volume relationship of the bladder (Measurement of detrusor pressure during controlled bladder filling) • filling medium either gas (CO2) or liquid (water, saline, or contrast material at body temp). • liquid cystometry is more physiologic. • ideally, filling should be performed in standing position. Detrusor pressure • Cannot be measured • It is estimated/calculated by the automatic subtraction of rectal pressure (an index of IAP) from the total bladder pressure, thus removing the influence of artefacts produced by abdominal straining Pdet = Pves - Pabd Filling Cystometry Failure to store Bladder Outlet 1. Overactivity 1. ISD 2. hypermobility 2. hypersensitivity 3. Combination Filling Cystometry: Aim Used to assess 1. 2. 3. 4. Bladder sensation, Detrusor activity, Bladder capacity, Bladder compliance, 5. Outlet incompetence. Filling Cystometry: Technique • Patient preparation: History and Examination MUS Explain the procedure Voiding Catheterization Measure the residual urine • Patient may be investigated supine, sitting or standing. Filling Cystometry: Technique • • • • • The transducers are calibrated. Zero setting. Connect the catheter to the cystometer. Start recording and infusion. Instruct the patient to report (FD), strong desire to void, urgency, cystometric bladder capacity (CBC) Filling Cystometry: Technique • The patient is asked to cough every minute during filling and after voiding to ensure that the catheters have not become displaced during micturition. • If the spikes are not identical, lower traces, then the explanation maybe : – – – – There are bubbles or Leaks, Catheters are mal-positioned Interference with the measurement of pabd due to faecal loading. • All these points must be checked and the cough repeated until the proper pattern is observed. Filling Cystometry: Technique Pabd Pves Vinfus Filling Bladder Pump Pves Pabd Recording Bladder Pressure Reaction during Filling With Control of Abdominal Pressure Pressure Transducers Filling Cystometry: Technique Pves Pressure P ves Proximal Transducer Filling Line Peristaltic Pump Filling Cystometry: Out Put • Curves (Traces) • Results (Table) • Report (Word) Filling Cystometry: Results Events Pdet cmH2O Volume ml Compliance ml/cmH2O Basic Pressure First Desire Normal Desire Strong Desire Urgency Max Cysto. Capacity BP FD ND SD UR CC 3 7 12 21 30 32 20 160 270 440 575 610 35 22 19 15 20 18 Filling Cystometry: Traces interpretation Principles • If a change is seen in both Pves and Pabd but not in Pdet, then it is due to raised IAP. • If a pressure change is seen on Pves and Pdet and not on Pabd, then it is due to a detrusor contraction. • If a change is seen on Pves, Pabd and Pdet, then there is both a detrusor contraction and raised IAP. • If a pressure change is seen on pabd with no change in pves and a consequent fall in pdet then this due to a rectal contraction. Filling Cystometry: Traces interpretation Post void residual urine • Post void residual urine above 300 ml, who have a pressure Rise at end pressure above 25-30 cm H2O, carry a risk of more than 50% of developing dilatation of the upper urinary tract. • In-and-out catheterization has been regarded as the gold standard. • Transabdominal ultrasonography is non-invasive and the method of choice, based on calculations using different formulas (an example is 0.5 x length x height x width of the bladder). Filling Cystometry: Traces interpretation Pitfalls of PVU • A delay time between voiding and measurement is the most frequent cause of a false positive • Voiding in unfamiliar surroundings, • Voiding on command, • A partially filled or overfilled bladder, • Vesicoureteric reflux • Bladder diverticula, • Inproper catheter emptying technique, Filling Cystometry: Traces interpretation 1-Bladder sensation • In a normal bladder, first desire often occurs at a bladder volume of 100-400 ml, depending on the filling rate, position and catheter used. • FD < 100 --- Bladder hypersensitivity • FD > 400 --- Patient never experiencing a strong desire to void -------Reduced sensation Filling Cystometry: Traces interpretation • Absent sensation ----indicative of a neurological condition such as spinal cord trauma 2-Detrusor Activity The normal detrusor remains quiescent during filling and detrusor overactivity does not occur under any circumstances (e.g., during the provocation tests(Provocative Cystometry) used in an effort to uncover detrusor overactivity (DO)) Provocative Cystometry Provocative cystometry involves a series of triggering procedures aiming to elicit reflex detrusor activity. Physical Provocation -Rapid bladder filling (>100 ml/min), -Jumping up and down , -Coughing, -leaning forward, - changing posture (from supine to sitting or standing), -Crede maneuver (suprapubic tapping) may help trigger unstable detrusor contractions. Filling Cystometry: Traces interpretation 3-Bladder capacity, • The normal bladder capacity is in the range of 300 to 500 mL; • Cystometric bladder capacity (CBC) if the resting pressure reaches 30 cm H2O • In infants and in some neuropathies CBC can be taken as the volume at which the patient starts voiding. Filling Cystometry: Traces interpretation 4-Compliance: • Normal bladder is highly compliant,and can hold large volumes at low pressure. • Compliance is the change in volume divided by the change in detrusor pressure during that change in bladder volume and is expressed as ml/cm H2O (C = V / pdet). 12-29 ml/cmH2O • Normal pressure rise during the course of CMG in normal bladder will be only 6-10 cmH2o. • Decrease compliance = > 20 ml/cmH2o, poorly distensible bladder. • Increase compliance Filling Cystometry: Traces interpretation 5. Outlet incompetence. - competent - incompetent Voiding Cystometry EMG Pabd Pves Qura Pves Pabd EMG Qura Recording Bladder Pressure Abdominal Pressure Electromyography during Voiding Phase Voiding Cystometry Patient In sitting position Ask the patient to void without straining Equipment Transducers Bladder level Flow rate Sensitivity 5 ml/sec. EMG Sensitivity 10 µV. VOIDING CYSTOMETRY. l EMG Pves Pabd Pdet Qura VB QM PM Vura VE Time 10 sec/Div Voiding Cystometry. EMG DSD Pves Pabd Pdet Qura QM VB PM Vura VE Time 1 min/Div C FS ND S D UR CC Normal filling cyst FS UR ND SD Increased BL sensation Reduced sensation Absent sensation 1. Sensation “sensation against volume” No involunatry det contration 2. Detrusor function Pdet 60 Terminal DO Phasic DO No increase in Pdet 500 CC 3. Compliance Steady increase Det P 250 low compliance CC 4. Cystmetic bladder capcity DOV Decreased compliance hypersensitivity Decrease Max CC Urgency, frequency, nocturia Leak Each Phasic DO U U Phasic detrusor overactivity incontinence Involuntary voiding Terminal Involuntary DO Terminal detrusor overactivity incontinence Involuntary voiding Terminal Involuntary DO Terminal detrusor overactivity incontinence No increase Det P leak Urodynamic Stress incontinence No increase Det P leak Urodynamic mixed incontinence Filling Cystometry: Traces interpretation Pabd Pves Pdet Cystometry trace showing the patient straining (S), a cough superimposed on an involuntary detrusor contraction (C + U) and an involuntary detrusor contraction (U). Pves Pabd Pdet Rectal contraction: characterised by a positive wave on the pabd trace and a negative artefact on the pdet trace. Pitfalls in Cystometry Causes of artifact in cystometry 1. Pressure measurement artifacts Air bubbles, Kinked tubing, Incorrect placement of the pressure catheters, Migration of the pressure catheters 2. Infusion rate artifacts (especially in neurogenic bladder) 3. Patient-related issues, Lack of cooperation, Outlet incompetence, Vesicoureteral reflux . Report Writing • • • • 1. 2. 3. 4. 5. 6. Click on report icon. Word sheet will be displayd. Fill data on the space. Using the traces & result write down :Bladder sensation, Detrusor activity, Bladder capacity, Bladder compliance, Outlet incompetence. PVU.