I worked at a University Hospital as a Senior Nursing Associate. When we were checked off in the lab (at school) and checked off 3 times with direct supervision by a nurse. We were allowed to be delegated blood draws, catheters, dressing changes, sugars, trach drsg changes... But remember it is up to the nurse to delegate these tasks and the should be sure of the competency of their aides. I loved the extra practice and it allowed me to keep my skills sharp. Its a great role transition for new nurses.
Nurses aides technically are not to be assessing pts. but any good nurse knows that you have to contantly assess, assess, and re-assess. So I can see you shock when techs do a drsg change ... "without assessing".