Quote from soutthpaw
From what my instructors have told me and from RN's I have asked, Almost never... What you can get by percussion (or tactile fremitus) you can also get other ways, primarily auscultation.
It's true that RNs never need to perform percussion. It is not true, though, that the same information is gained with auscultation.
Percussion is for distinguishing solid structures and fluid filled structures vs. air-filled. If you can do that with auscultation, then good on you!
I'll grant you that the percussion assessment is not relied upon - but in the past it provided useful information in the decision whether or not to obtain imaging aka expose pt to radiation. In the "way past" it was part of an assessment needed to decide whether to take the patient to surgery or not, without the benefit of imagining or advanced imaging. Anyone who has had the chance to observe an "experienced" general surgeon would see that they are gaining particular info by percussing; it's not rare that they're able to predict the CT results - the CT is merely a necessary formality in some of the very common cases. It's kind of a neat thing to see. Somewhat archaic appearing? Yeah, probably. But still pretty impressive.
Anyway, here's a not-fancy-but-maybe-interesting page...
Scroll about half way down to the percussion section
A Practical Guide to Clinical Medicine