Urology neurogenic bladder urodynamics.pptx

Urodynamics

1. Urodynamic Techniques By Dr Sajad Sultan Lone Moderator: Dr Yasir Ahmad

2. Why Urodynamics ? Patient symptoms are often misleading The lower urinary tract, both during filling and emptying, is a dynamic system. Urodynamics is a dynamic study of urine storage and transportation

3. Types Simple and Complex Simple : Micturition Charts,Voiding Diary, Frequency Volume Chart, UFM, Pad Testing, Surface EMG Complex : Pressure flow study, Cystometry , UPP, Needle EMG, Whittaker Test

4. Aims To reproduce the patient’s symptomatic complaints during urodynamics , and To provide a pathophysiological explanation by correlating the patient’s symptoms with the urodynamic findings To increase diagnostic accuracy above that which can be achieved by nonurodynamic means. To predict problems that may follow treatment interventions To assess the natural history of lower urinary tract dysfunction

5. Environment To be performed in a calm environment with full privacy Procedure to be explained to the patient Give adequate time to each patient No antibiotics are required

6. Cystometry Pressure-volume relationship of the bladder is measured Normal and abnormal lower urinary tract function described in terms of bladder and urethral behaviour during the storage and voiding phases

7. Performing Filling Cystometry The role of urodynamics is to reproduce the patients symptoms The role of urodynamics is to provide a pathophysiological explanation for the patient’s complaints There should be a continuous dialogue between the investigator and the patient throughout the investigation to assess Bladder sensation Detrusor activity Bladder compliance Urethral function Bladder capacity

8. Bladder Sensation First sensation of filling ( FSF) It occurs at approximately 50% of cystometric capacity Normal desire to void ( NDV ). The feeling that leads the patient to pass urine at the next convenient moment, but voiding can be delayed if necessary. It is felt at about 75% of cystometric capacity Strong desire to void ( SDV ). Persistent desire to void without the fear of leakage. It is felt at approximately 90% capacity Urgency . This is defined as a sudden compelling persistent desire to void which is difficult to defer Pain

9. Abnormal sensation Increased (hypersensitive) : there is an early first sensation of filling (FSF) at less than 100 ml which, instead of passing away until the normal desire to void (NDV) occurs, persists and increases, limiting the cystometric capacity to less than 250 ml. Reduced . Reduced sensation is characterised by a later FSF and NDV, with the patient never experiencing a strong desire to void (SDV) or urgency Absent . Absent sensation necessitates the patient passing urine “by the clock”

10. Detrusor Activity The normal detrusor remains quiescent during filling and detrusor overactivity does not occur under any circumstances Detrusor relaxes and stretches to allow the bladder to increase in size without any change in pressure (accommodation) Detrusor overactivity exists when, during the filling phase, there are involuntary detrusor contractions “Detrusor overactivity incontinence”

11. Normal filling cystometrogram with almost no increase in p det as the bladder fills

12. Is DO Normal or Abnormal? Do you feel anything now?” “Is this the feeling that gives you trouble in your everyday life?” Involuntary detrusor contractions occurring at increasing frequency and with increasing pressure as the bladder fills

13. Bladder Compliance Intravesical pressure should change little from empty to full Relationship between bladder volume and bladder pressure (Δ v / Δ p ) Increase in bladder volume per centimetre of water increase in pressure (ml/cmH2O) With a capacity of 400 ml the change in pressure from empty to full should be less than 10 cmH2O (40ml/cmH2O) Dependent on the rate of bladder filling, on bladder function, and on the neurological state of the patient

14. Bladder Capacity Cystometric capacity Maximum cystometric capacity (MCC) Maximum anaesthetic bladder capacity

15. Sterility of Transducers and Tubing The external transducers need not be sterilised, but should be flushed through with chlorhexidine solution (0.2%) Catheter tip transducers must be kept sterile using Cidex

16. Media Used for Bladder Filling Water or physiological saline Radiographic contrast material if videourodynamics is being performed

17. Temperature of Filling Fluid Fluid at room temperature (70ºF or 22ºC). Important not to use cold fluid (lower than 20ºC) because, the use of cold infusion fluid stimulates detrusor contractility at low bladder volumes

18. Patient Position During Cystometry The patient is catheterised when supine Can fill the patient either sitting (in the case of women) or standing (in the case of male patients) because the supine position does not reflect the everyday stresses to which the bladder is subjected Patients complain of bladder symptoms only when they are active (erect)

19. Rate of Bladder Filling ICS recommends that the exact filling rate is stated for each test, although the ICS formerly defined three categories of filling rate: Slow-fill cystometry : up to 10 ml/min. Medium-fill cystometry : between 10 ml/min and 100 ml/min. Fast-fill cystometry : when the rate is greater than 100 ml/min A convenient rate, which does not prolong the test unduly, is 50 ml/min to 60 ml/min The fastest physiological urine production for any individual can be calculated by dividing the body weight (in KG) by four (e.g., 20 ml/min for an 80-KG man). Faster flow rates may produce artefactual low compliance in patients suspected of having detrusor overactivity

20. Quality control: the patient is asked to cough every minute during filling and after voiding to ensure that the catheters have not become displaced during micturition

21. Voiding Cystometry Premicturition pressure is the pressure recorded immediately before the initial isovolumetric contraction Opening time is the time elapsed from the initial rise in detrusor pressure to the onset of flow Opening pressure is the pressure recorded at the onset of measured flow Maximum voiding pressure is the maximum value of the measured pressure during voiding Pressure at maximum flow is the pressure recorded at the time of maximum flow rate.

22. Performing Voiding Cystometry If the patient has little sensation it is important to use the functional bladder capacity from the frequency- volume chart as a guide to cystometric capacity Void to completion if possible

23. Interpretation of Voiding Cystometry Detrusor Activity: Normal when the detrusor contracts to empty the bladder with a normal flow rate Underactive when either the detrusor contraction is unable to empty the bladder or the bladder empties at a lower than normal speed, and Acontractile when no measured detrusor pressure change occurs during voiding

24. Detrusor underactivity: a poor detrusor contraction results in a fluctuating and interrupted flow wave.

25. Acontractile detrusor: PFS in a male patient who voids by straining without any sign of detrusor contraction

26. Assessment of detrusor contractility by using the “stop test” : p det , iso

27. Stop test: small increase in P det,iso (20 cmH2O) in a female patient

28. Detrusor Underactivity When the patient cannot initiate micturition and it is unclear whether this inhibition is psychogenic or neurogenic Psychogenic suppression of detrusor contraction is less common if the patient is put at ease

29. Detrusor-sphincter dyssynergia (DSD) Seen only in patients with neurological disease and most classically in high-level (cervical) spinal cord injury Phasic contractions of the intrinsic urethral striated muscle during detrusor contraction

30. Dysfunctional voiding (DFV) Produces the same urodynamic pattern as DSD but occurs in a different group of patients and has a different cause In children who are neurologically normal but present with urinary incontinence and/or infections The interrupted flow in these children is due to pelvic floor overactivity rather than to intrinsic striated muscle as in DSD

31. How is the diagnosis of BOO made? by plotting the maximum flow rate ( Q max ) against detrusor pressure at Q max ( p det , Q max ) into the ICS nomogram which is derived from the Abrams-Griffiths BOOI = pdet , Q max – 2Qmax If the BOOI is greater than 40 then BOO exists; if it is below 40 then no definite BOO exists

32. Example Traces

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34. Thank You