@Jeruba I can understand why it worries you, I have similar worries about being put on my right side. It not only hampers my breathing, but also after a short time causes very bad pain in my neck and can last for a long time.
I can tell you that when I went into the emergency room after my accident they screwed up all sorts of things. Luckily, I was conscious, but that didn’t mean there were not some mistakes made that caused me additional injury that should not have happened, and I could have been very seriously hurt when they left me alone on a bed without the side railings up. None of us knew yet that I had extreme vertigo and if I turned the slightest bit left or right or tried to sit up I was out of control trying to regain stability. I easily could have fallen to the floor if I had shifted at all.
I don’t remember if they kept me flat on my back initially in the hospital, but I am pretty sure in the ambulance I was flat on my back, because I remember looking up at the ceiling. The EMT was right next to me watching me the entire time. I felt like his sole job was to watch me.
I have printed out instructions if I am ever unable to speak for myself and given a copy to my husband and sister and it is in my phone in the medical app, and that app does not require my password to unlock, but I think @caravanfan once confirmed for me that hospitals don’t bother to look at the medical information we put in our phones. I don’t understand why they don’t check people’s smart phones in the ER since almost everyone has a smart phone. You will see it on your password screen in the bottom left corner if you have an iphone, it says “Emergency” and then you go to “Medical ID.” The app icon is white with a pink heart to enter the information. But, again, I’m not so sure medical personnel check it, maybe EMT’s know about it. Here is a good youtube about it, I have very complete information in mine.
You can get a medical alert bracelet, I think people mentioned that above.
Also, if your city or county uses the vial of life program, I highly recommend it. Where I live you put a sticker on your front window and the EMT knows you have a vial in your refrigerator. I think the EMT’s check for a vial no matter what it is so common here. The vial looks like a huge prescription pill bottle, and it has a paper in it where you fill out basic medical information so the EMT’s have immediate information. We pick up the vials for free at the police department. This is a general website on the vial of life program, but you can check your county website too. On this website for the general program in the US it looks like you put the info in a ziploc bag and keep it on your refrigerator. If your county or city does not already do the program it would be great to inquire about starting it. This website is my county’s website, I just googled “Lake County Vial of Life” and it came right up, maybe check your city or county.