[dammy]

what additional professional qualifications will need to have before I can practice OHN anywhere in the US?

[sharrie]

It would help if we knew what qualifications you have already, I assume that you are a qualified nurse?

Also are you working in the US at the moment as there are many issues with nurses from other countries getting work permits within the US due to retrogression.

It is worth you looking at the international forums to see exactly what you would need to do first