A flail occurs when several pieces of ribs break at several different points, leaving a broken piece of chest wall which severely restricts respiration. A flail chest is a serious, life-threatening injury that requires immediate medical attention. Always dial 9-1-1 in case of medical emergency. The 9-1-1 operator should stay on the phone, so she is available to talk you through any sudden additional distress the patient may exhibit.
There are steps you can take to help the injured patient make it to the hospital so he'll be alive to receive that medical assistance. Here is what you can do to treat the flail injury on the scene:
The first step is recognize the signs of a flail injury. Flail presents as severe respiratory distress coupled with half the chest wall moving in, while the other half moves out, during respiration. It is important to move the injured party as little as possible at this point. The only movement that should occur is to roll him onto his injured side.
The next step is to treat the victim for shock. Start by elevating the injured person's feet and wrapping him in a blanket or coat. Place a piece of clothing that has been rolled up under the fracture site to support it. This will help control the pain, and help the victim breathe.
Now it's time to place pressure on the injured area to help restrict movement of the chest wall. If you are alone with the person, you will want to continue doing this until help arrives. If not, then you may choose to send a second person out to fill a bag with sand to place against the flail site. Use whatever you have handy to secure this bag against the injury, it will make it easier to move the patient when help does arrive. During this whole process it is important to continue to watch for signs of shock (which include a fixed gaze, numbness, cold hands and feet, and changes in speech patterns), and also for signs the person has stopped breathing. If he has stopped breathing, then gently roll him back onto his side and administer rescue breathing. Chest compressions are not a good idea in flail cases.
An injury this severe is very traumatic for the victim, but also for his or her caregivers. The best thing that you can do during this time is attempt to remain calm. If you are frantic you may cause the injured party to feel even more stress than they're already under, which increases the possibility of severe shock and can make recovery that much more difficult.