How are urinary catheters sized?

I'm often asked how are urinary catheters sized and what do the different colour funnels on the catheters mean?

Indwelling and intermittent catheters are sized using a number system and maybe denoted by Charriere (Ch), French gauge (Fg) or French (Fr).

1 Ch, Fg or Fr is equal to 1/3rd of a millimetre therefore a size 12ch would be 4 mm in diameter, measuring the outside width of the catheter tubing.

Each Ch, Fg and Fr is also given a colour coding so identification can be distinguished at a glance.

This sizing is universal, on indwelling foley catheters the size should be written somewhere on the catheter near where it connects to the drainage bag.

Intermittent catheters can be coded by having a coloured funnel. Wymedical catheters and dilators can be differentiated by the different coloured funnels.

Catheter Sizing

Catheter Funnel Colours

What is best practice?

I have been around for nearly 30 years within the field of urology and continence in various different roles. From specialist nurse in urology and setting up a continence advisory service within the NHS to nursing and sales roles or large and smaller companies before choosing to set up Wymedical.

Setting up my own company has been enjoyable if not challenging but one thing that really comes to the forefront is ‘What is best practice?’

When I started my RGN nurse training at Westminster hospital in London attention to detail and best practice were instilled in us, every ward and department had a procedure folder where you could refresh your knowledge. In this day and age you are expected under the NMC code http://www.nmc-uk.org/The-revised-Code/ to ‘Always practise in line with the best available evidence’ yet I continuously come across nurses and carers carrying out procedures differently to how I would have undertaken them. So this comes back to the question, ‘What is best practice?’ and then adds further questions such as ‘How is best practice monitored? Along with ‘Where do people go to gain knowledge?’

I am passionate about wanting to maintain best practice and improve practices, my first step is writing this blog which I hope will get people thinking and provoke discussions in different aspects of continence and urology.