The effect of position (sit/stand up vs supine position) on urge sensation in volunteers and in patients with overactive bladder syndrome

We would like to study the regulation mechanism of the bladder. This is in the
light of finding new treatment strategies for OAB. Patients suffering from OAB
have symptoms of urgency and/or frequency.
according to recent studies the prevalnce of OAB is about 17 % of the
population opver 40 years , in the western world
We would like to study the relationship between position and bladder sensation
in both OAB patients and healthy volunteers.

The primary objective of this experiment is to describe via an observational
study the relation between conditions of sitting/standing up versus laying down
in terms of bladder sensation in both volunteers and patients with OAB.
We also want to explore if there is a relation between bladder volume and the
sensation of urgency.
Furthermore we would like to study the level of self-consciousness and bladder
filling correlated to voided volumes and the perception of the sensation during
the filling phase of the bladders in these patients

We want to explore if there is a relation between the postural position, the
bladder filling, the volume voided, the trait and state level of patient
self-consciousness and the sensation of urgency during the filling phase in
these patients with OAB.

Group 1. OAB Patients:
Patients will be recruited from our patient pool of the urology department.
That means known or new patients from our out patient clinic in Maastricht
diagnosed with OAB. Patients will be asked to go to a toilet and empty their
bladder on inclusion at the outpatient clinic. The residual volume in the
bladder will be assessed. All patients with a post voidal residu of more than
100 cc will be excluded from the study. Since this will influence the urge
sensations and therefore the study outcome.
All patients using anticholinergic medication will be asked to stop taking
their anticholinergic for at least 10 days prior to the study date to eliminate
the effect of anticholinergics on urge sensations.

The inclusion criteria for patients is > 8 micturitions per day, and a minimum
of one episode of urgency per day).There will be no catheter insertion or any
medication used. After receiving detailed information about the study and
receiving informed consent, patients will be asked to come to our outpatient
clinic (urology function room) after drinking 1 litre of water (SPA blauw) at
home prior to arrival. At arrival patients will be asked to fill in a self
consciousness questionnaire which will take about 5 minutes. Then they will be
asked to drink another 0.5 litre of water and drink additional 250 ml of water
every 15 minutes in our clinic for one hour. We will wait for them to void when
they can in a special toilet that can measure the amount of urine flowing in
it.
.
From that urine, a sedimentation test will be done in order to assess if there
is any ongoing urinary infection, which can influence our study data. After
voiding the patients residual urine volume will be assessed, non-invasively by
an ultra sound scan 3D echo. Every 10 minutes participants are asked to change
posture (lying down or standing up). Just before and just after this posture
change they grade their bladder sensation at that time point. For that purpose
we will use a special visual analogue scale (VAS) on which the patient can
point out his feeling in a scale running from no sensation at all to very
strong voiding sensation. Furthermore they will be asked to complete a
seven-item VAS-scale that measure different aspects of level of state
self-consciousness. Patients will be asked to keep their urine as long as
possible and only void at a strongest urge sensation they can withstand.




. When they can*t hold the urine any longer, they will void in the toilet and
their voided volume will be measured. And again an ultrasound bladder scan will
be conducted to assess the residual volume post micturition. This whole session
will take between 60 to 120 minutes depending on the patients functional
bladder capacity and the time that he can hold up his urine.

The study procedure will be performed two times on two different days within a
time period of 10 days.

Group 2. volunteers without OAB symptoms.
Volunteers will be recruited by means of a newspaper add or a poster. After
receiving detailed information about the study and receiving informed consent,
these volunteers will be asked to come to our outpatient clinic (urology
function room). Subsequently they will be subjected to the exact same protocol
as Group 1.

There are no direct riscs in taking part of this study. stopping
anticholinergic medicatioon might re introduce the patients voidning complaints
but these complaints will dissappear after restarting the medication. Drinkng
large amounts of water might be dangerous to patients with congestive
heartfailure, therefore these patients are excluded from this study.