Maryland Family Law Code §§14-101-14-309 provides statutory regulations for Adult Protective Service.
One interesting feature of the law is that it provides legal protection for those who in good faith initiate or participate in a nursing home investigation. It other words, you have immunity for reporting an elder abuse situation even if you end up being wrong.
Honestly, I think this just repeats Maryland law. The following concerns deserve attention: abuse, neglect, and exploitation. Although it has nothing to do with potential nursing home lawsuits, another huge concern that needs to be reported is self-abuse, the inability of a vulnerable adult to provide for his/her physical or mental health and well-being.
You can find more information about Adult Protective Services in Maryland from the Maryland Department of Human Resources