Informed consent is required for essentially any procedure which carries risks of complications unless those complications are minor or extremely rare. While I am not familiar with all state law, I do know that California requires the physician who will be performing the procedure to expain the rationale for the procedure, the risks, benefits and options and must obtain the patient's consent. A nurse may not obtain informed consent because the likihood of risks/benefits and other medical options are outside of nursing scope of practice and the nurse is not the one performing the procedure. While a nurse may be able to explain the procedure, answer questions, etc., it is fundamentally a physician's duty to obtain informed consent (at least in California). This should be distinguished from having a patient sign a piece of paper stating that the risks and benefits have been explained to them and they consent to the procedure (after the physician has already obtained informed consent and documented such consent in the medical record.)