If your doctor plans a surgical intervention, he/she will tell you about all the dangers; that is an obligation to take informed approval, after giving information in detail about the other options and risks of the operation. Of course, also you are obliged to give consent; that is, to give approval after evaluating all the information given to you during this acknowledgment and after receiving and understanding the answers of all your questions. Of course, both you and your doctor have the right to cancel these decisions.
Since even the palest ink is stronger then the sharpest memory, after all in these matters; a written copy with wet signature on it remains in the patient. Do not think that it is a new invention, even 400 years ago in this country; a surgeon and the patient were obliged to sign a similar agreement in the presence of the kadi.