Advice after your nerve block for surgery
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What is a flow rate and bladder scan?
This leaflet tells you about what happens when you have a flow rate and bladder scan. It explains what is involved and the benefits and risks. It may make you think of things you would like to discuss with your doctor/s.
What is a flow rate test?
This is a very simple procedure to measure the rate and volume at which you pass your urine. The test will help the doctor to diagnose your problem.
How do you prepare for the test?
It is important to attend with a full bladder so we can get an accurate reading. You may need to drink more fluid than you normally do. Please drink several cups of fluids (water, juice, tea or coffee) at least an hour before attending the department and try not to pass urine until you get here and perform the test.
What do you do when you get to the department?
When you arrive at the Outpatients Department we will carry out the test as soon as possible so that you are not left waiting. Please tell the clinic nurse when you feel your bladder is full, we will ask you to pass urine into a funnel attached to a special machine. You will be able to do this in private. You must not force the urine out, please relax and let it flow naturally. This will give a more accurate picture of what is happening when you go to the toilet.
We may ask you to do more than one of these tests if you attend for another appointment as a series of recordings can give a more reliable picture than a single recording.
If you are unable to hold onto your urine and can’t drink the fluid before you make the journey Outpatients, please let us know and we will give you the fluid to drink once you arrive.
Sometimes the clinician may examine you before the flow rate test; the clinic nurse will tell you if this is necessary
What are the risks?
There are no significant risks with this test.
What is the benefit of this procedure?
To fully assess rate of urine flow, to determine if there is any obstruction to flow and check whether the bladder is empty when you have finished passing urine.
Are there any alternatives to this procedure?
No, there are no alternatives to a flow rate scan. If there are problems with flow or emptying you may need some tablets or a surgical procedure to correct these problems.
What happens if I decide not to have this procedure?
If you decide that you do not want to have this procedure then you need to discuss this with your consultant or nurse. If you have problems passing urine satisfactorily, this may damage your kidney.
Bladder scan
After your flow rate test, it may be necessary for the nurse to scan the bladder to see whether you have emptied your bladder fully.
The scan is a painless procedure. A probe is placed on your skin over the area to be scanned. The probe sends out high frequency sound waves which enter the body and are reflected back from the bladder. A water based jelly substance is used on the skin to help the probe move and send the sound waves properly.
The probe will be moved backwards and forwards over your lower tummy area. The amount of urine left in your bladder will show up on a screen. Once the volume of urine has been calculated the nurse will stop scanning and remove the jelly from your skin.
What happens after the flow rate test?
The information obtained from these tests will be sent to your doctor who will speak, or write to you about what will happen next.
If you have any questions please ask the Outpatient Nurses when you attend your appointment.
Contact us
If you have any queries relating to this information, please contact the Urology service.
About this information
Service:
Urology
Reference:
Z/022
Approval date:
12 July 2024
Review date:
1 April 2027
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Important note
This page provides general information only. It is developed by clinical staff and is reviewed regularly every 3 years for accuracy. For personal advice about your health, or if you have any concerns, please speak to your doctor.