I believe the staff will try to get your details on arrival but these will be treated with confidentiality. Depending on why you wanted to go to A&E you could ring NHS direct on 0845 4647 for some advice and support instead. Or if you would like the morning after pill for example you could go to a pharmacy, where I believe you do not need to give your details. If you need to go to A&E please go, in my experience the staff are very respectful and will help.