Yes you may be able to file such a lawsuit on behalf of a loved one, it depends on a few things. For example, the relationship that you have with the loved one. If it’s your spouse then you should be able to file such a lawsuit. If it’s your child, also. And if you have the proper paperwork, things like a power of attorney, or a healthcare surrogate form allowing you to make healthcare decisions for that person, then you can possibly file the lawsuit on their behalf. If they’re incapacitated, such as in a coma, or if they’re not fully functioning mentally.