I am sorry you are going through this...
We are not lawyers and per TOS cannot give advice. But, it has been my experience, that essentially "they" can do whatever they wish (unless you have a signed contract), but you as the nurse can refuse any assignment that you feel you are not qualified to safely perform. Many, if not all, BON have statements that give specific information and regulations within the stats nurse practice act.
and my state of Massachusetts
Massachusetts Nurses Association - Nursing Resources - Nursing Practice - Accept or Reject an Assignment
What I would do is let you DON know of your concerns and tell that you cannot accept an assignment that you have not been properly oriented to and feel safe to do, that they as a nurse as well, should understand this......and that you will require an orientation in order to full fill your new duties and develop the "proven" competencies as required by The Joint Commission. See where this new directive goes from that point.
Now, Unless you entered into a written contract that states exactly what your duties and compensation are/were to be prior to the start of your employment there is not much you can do. Contracts such as this are usually only offered to very high level employees, 99% of the rest of us poor slobs have an "employee-at-will" relationship with their employer, meaning that the employer can dismiss the employee at any time without notice (although most employers will provide some notice and perhaps severance pay). Your job description does not rise to the level of an employment contract.
Unfortunately, in this economy, you are not alone -- these kinds of things are happening all over the country because of the poor economy and there is simply not much you can do about it. In this economic climate, employers know they have the upper hand, and some companies are doing well and still laying off people and making others remaining do more work than ever before. It is a catch 22 -- you can leave the job but may have problems finding another one right now.
An employer may hire someone for a particular job and then the job is eliminated or changed over time. Just because the employer hired someone into a specific job does not mean that the employer is obligated to maintain that specific job no matter what transpires regarding technology, for example, and other factors that affect company operations.
The employee always has the right to leave if the changes in the job title, job requirements or responsibilities are not acceptable to him/her. But employers have the right to determine what workforce they need to run the company efficiently and effectively--and profitably (code for getting rid of the expensive employees). Especially if you live in an "At will" state.There are "right to work" states that may cover this somewhat......that is where you need to talk to an employment lawyer or your states DOL website.
I know it's not what you wanted to hear.....I wish you luck