Is this true about catheter size?

[Faeriewand, ASN, RN]

A fellow student and I are just not sure about this. We wrote it in our study guide for our nursing science final but are not sure about the accuracy so please can someone reply with whether this is true or not?

*Indwelling urinary catheter-size 16Fr - an indwelling catheter is placed when a client is unable to void naturally or had had surgery. Also called a retention catheter; it is inserted into the bladder, anchored and drains urine continuously. Examples include the Foley. ; size 14-16 tube in normally used. The higher the number the smaller the tubing; the smaller the number the larger in diameter the tubing.

Thanks so much. The final is in a few days and the study guide is nearly completed with maybe 2 or 3 more to go. Just wanted to make sure this was the correct information. :)

[UM Review RN, ASN, RN]

here's what googled:

foley catheter: definition and much more from answers.com

the relative size of a foley catheter is described using french units (f). the most common foley catheters typically range from 10 f - 28 f. 1 f is equivalent to 0.33 mm = .013" = 1/77" of diameter. [color=#003399][1] thus the size in french units is roughly equal to the circumference of the catheter in millimetres

so it would seem that the higher the number, the larger the cath. i agree with that. we usually use a #16 fr for permanent indwelling caths and a #14 fr for straight caths.

good luck on your test!

[ZASHAGALKA, RN]

The higher the number the smaller the tubing; the smaller the number the larger in diameter the tubing.

This applies to 'gauge', generally related to needle size. The higher THAT number, the smaller the lumen.

In re: French size - the larger the number the larger the diameter.

I think you are confusing different measuring systems for different devices.

~faith,

Timothy.