The 2nd number of the NOC code tells you if it is a skilled job or not. 3413 has the 2nd number as 4 so it's not skilled. If it was 0, 1 or 2, it would be skilled. If it's 4 or 6, not skilled.
BC and AB have some semi or low skilled job in their PNP. You need to check if either of them has nurses aid. If not, then you can not apply for PNP as a nurses aid. I don't think AB has it. I think BC has a special class for health care workers so maybe you need to call them and ask, see BC program at
http://www.cse.gov.bc.ca/ProgramsAndServices/PNP/SO/so_publicsector.htm