Catheters are sized according to a so called "French Scale," as well as, by the size of the balloon at the in-dwelling tip end of the "Foley" style catheter. The "French size" scale begins in the single numbers, e.g., #8 Fr (a very small diameter catheter) and runs all the way up past 30 Fr ( a very large diameter catheter). In other words, the higher the Fr number the larger the diameter of the catheter. Generally, a catheter smaller than a 14Fr is considered "child sized" and is not generally used to cath a normal size adult patient. There are exceptions but that's the general rule. You may wish to VIEW THE FRENCH SCALE here.



CONVERTING MILLIMETERS TO INCHES

If you would like to convert millimeters (mm) to inches, using a hand calculator, just divide the number you wish to convert shown in millimeters (mm) by the number 25.4. For example, if you want to know the diameter in inches that a 16Fr catheter represents, just look across the scale to the right from 16FR and you will see the number 5.3 (mm) - to convert the 5.3 mm into inches, first enter 5.3 into your calculator and then press the divide sign button, next enter 25.4 and press the equals button - in this example you will get the number .209 (rounded off). So, a 16FR catheter is about 1/5 of an inch in outer diameter! Sounds easy - it is easy - just try it - it's almost addictive once you get the hang of it *smile*.

Foley-style catheters are different from "regular" vinyl or red rubber nelation style catheters in the following way:
because a Foley-style catheter is designed to remain within the bladder for a period of time greater than just a few minutes (often hours or days) it comes equipped with a small balloon at the in-dwelling end which is designed to be inflated with sterile water at the time the catheter is inserted into the bladder so that the catheter will not inadvertently pull out through the neck of the bladder. This "balloon tip" can be very small (5cc) or much larger (30cc).
It is best left to the judgment of trained medical personnel to decide which size balloon Foley to use for a given patient.

Since not all urinary catheters are design to dwell within a patient for an extended period of time, not all catheters are made with balloon ends. The Foley-style catheter has a balloon end at its tip, whereas the nelation red rubber of simple vinyl catheter, does not have the balloon end at all. It is certainly possible to use a Foley-style catheter as a simple catheter ( just as one would use the nelation or vinyl cath) without inflating the balloon-tip
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Urinary catheters are packaged "sterile" and sent to the customer unopened and sterile. A sterile urinary catheter is designed for "single use" only and cannot be effectively sterilized for repeated uses. Never use a catheter more than once or for cathing more than one person - you will run a real risk of infection - it's just not worth the risk of contracting a UTI. Simply use a "single use" sterile urinary catheter once and throw it away immediately after use - period.

Catheter insertion is best left to trained medical personnel, or may be performed by a patient on himself after he has been instructed in "self-cath" technique by a qualified medical practitioner. Never attempt to perform any form of catherization unless you have been thoroughly trained by a qualified medical practitioner familiar with proper "catheter technique."