Describing the accident or mechanism of injury to medical personnel if you witnessed the trauma can be helpful. If you are there from the beginning, you can often provide information for the hospital personnel that will make their job easier. One of the most important things you can do is stay with the victim, talk to the victim, and reassure them that help is on the way. All of these things will help the victim stay calmer. Some common mistakes are not calling for help right away, trying to move the victim, or giving the victim water or something to drink.
Panic never helps.
Remember that you have to talk to the 911 operator and relate some information, as well as be as reassuring as possible to the victim that everything that can be done is being done, so you will need to stay calm. It is also important that if a person has been stabbed, never try to pull out or manipulate the penetrating object. The initial mechanism is shock and the body preserves blood flow to the vital organs. The arms and legs will get cold and they will start to shiver. Oftentimes they will feel thirsty because of internal bleeding.