My rule book states that when numbers are used with words as a compound modifier preceeding a noun a hyphen should be used.

So, if the above rule is correct, how should I edit this phrase:

a 4- French double-lumen 5-cm Arrow catheter was placed easily in the right internal jugular vein.

My problem is identifying the nouns. Are the hyphens placed correctly?

Thanks for all who helps me figure this mess out.
I never use hyphens in the circumstances you describe. As far as I'm concerned, four centimeters is 4cm, and a four year period is a four year period (i.e. write the word, not the digit).

When we say : it will be applicable for a four year period. or
A 4 year period,

where do we use a hyphen ?
 rommie's reply was promoted to an answer.