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Plain English Summary

Background and study aims
Urinary retention is the inability to empty the bladder completely. It is one of the most common complications after surgery and anesthesia. Urination depends on coordinated actions between the bladder muscle and the urethral sphincter muscles. Under the influence of epidural analgesia (pain catheter), patients may not feel the sensation of bladder filling, which can result in urinary retention and bladder damage. Epidural analgesia (pain relief) is provided with local anesthetics that block pain sensation. The anaesthetic drug bupivacaine blocks bladder muscle activity (a motor block), resulting in residual urine remaining in the bladder after urination, which requires monitoring or drainage. The epidural administration of a relatively new anaesthetic drug ropivacaine during labour has resulted in fewer motor blocks. The aim of this study is to find out whether using ropivacaine results in less significant changes in lower urinary tract function than bupivacaine, in patients undergoing renal (kidney) surgery.

Who can participate?
Patients undergoing renal surgery with normal bladder function.

What does the study involve?
Participants will be randomly allocated to receive either ropivacaine or bupivacaine during their surgery. Participants will also undergo tests to assess their bladder function before and after the surgery.

What are the possible benefits and risks of participating?
This study will improve our knowledge of bladder function during epidural analgesia. The immediate benefit to the participants will be that in case of normal bladder function no bladder catheter will be needed, which will reduce the risk of a urinary tract infection, a frequent complication following surgery. Due to the additional bladder tests in this study, there is a slightly increased risk for urinary tract infections. However, all the patients undergoing the bladder tests will receive antibiotics as recommended by the guidelines.

Where is the study run from?
Departments of Anaesthesiology and Urology of the University Hospital Bern (Switzerland).

When is the study starting and how long is it expected to run for?
From April 2015 to April 2017.

Who is funding the study?
University Hospital Inselspital (Switzerland).

Who is the main contact?
PD Dr. med. Patrick Wüthrich

Trial website

Contact information



Primary contact

Dr Patrick Wuethrich


Contact details

Department of Anaesthesiology and Pain Therapy
University Hospital Bern Inselspital Bern

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effects of thoracic epidural administered ropivacaine versus bupivacaine on lower urinary tract function: a randomized controlled study


Study hypothesis

To evaluate the epidural administration of ropivacaine on lower urinary tract function. The primary hypothesis is that thoracic epidural analgesia (TEA) with the local anesthetics ropivacaine leads to less significant changes in lower urinary tract function than bupivacaine as a control group, in patients undergoing lumbotomy incision for renal surgery.

Ethics approval

Kantonale Ethikkommission Bern (KEK BE) (Ethics Committee of Canton Berne), 10/03/2015, ref: 390/14

Study design

Randomized parallel-group single-centre interventional assessor-blind trial

Primary study design


Secondary study design

Randomised parallel trial

Trial setting


Trial type


Patient information sheet


Kidney surgery


All patients will receive a TEA placed at the insertion site interspace T7-8 or T8-9. Segmental blockade will be achieved using the solutions according to the randomisation.
Group 1: Ropivacaine 2 mg/ml (ROPIVACAIN Sintetica 2 mg/ml ™, Sintetica-Bioren, Couvet, Schweiz)
Group 2: Bupivicaine 1.25 mg/ml (BUPIVACAIN Sintetica 0.125 % ™ (Bupivacain 1.25 mg/ml – Fentanyl 2 µg/ml), Sintetica-Bioren, Couvet, Schweiz)

Intervention type



Phase IV

Drug names

Ropivacaine , Bupivacain

Primary outcome measures

Post-void residual urine volume (in ml) during thoracic epidural analgesia, measured before surgery (baseline) and on postoperative two or three depending of the patient’s mobility.

Secondary outcome measures

Urodynamic parameters of the storage phase and micturition (e.g. bladder volume at first desire to void, maximum cystometric capacity, bladder compliance, urethral pressure profile, detrusor activity, maximum detrusor pressure, detrusor pressure at maximum flow rate, maximum flow rate, pelvic floor electromyographic activity, incidence of urinary retention). Primary and secondary outcomes will be measured before surgery (baseline) and on postoperative two or three depending of the patient’s mobility. The method used will an urodynamic investigation and secondly assessment of the parameters of the voiding phase. Urodynamic investigations will be performed according to good urodynamic practice. After placement of a 6 French transurethral dual channel catheter and a 14 French rectal balloon catheter (Gaeltec, Dunvegan, Scotland), the bladder will be filled at a rate of 25 to 50 ml/min with Ringer’s lactate solution at room temperature. Parameters of both the storage phase (maximum cystometric capacity, bladder compliance) and voiding phase (detrusor pressure at maximum flow rate [PdetQmax], maximum flow rate [Qmax] and PVR) will be recorded. A TRITON™ multichannel urodynamic system will be used for all measurements (Laborie Medical Technologies Corp., Toronto, Canada). All methods, definitions and units will be in accordance with the standards recommended by the International Continence Society.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Written informed consent
2. Kidney surgery
3. Thoracic epidural analgesia

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Contraindications to epidural analgesia or refusal
2. Preoperative PVR > 100 ml
3. International Prostate Symptom Score (IPSS) > 7
4. Pregnancy (pregnancy test in all women who are not in menopause, exclusion for surgery per se)

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Urology Department
University Hospital Bern Inselspital Bern

Sponsor information


Department of Anaesthesiology, University Hospital Inselspital

Sponsor details


Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

University Hospital Inselspital

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

To be confirmed at a later date

Intention to publish date

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes