adrenaline
yes
An adrenaline rush.
Rapid heart beat, increases strength, vasoconstriction.
Call 911 before you start CPR.
The first hint is that they require CPR.
No it can not.
You can't get into any legal trouble for performing CPR on a person
Adrenaline is released as a defense mechanism. It is released when the person is in potentially life threatening danger. Adrenaline can cause an increase of strength sometimes to unbelievable extents. Adrenaline also causes the person to focus on the situation rather than other less important things such as pain.
CPR is known for saving lives during a cardiac emergency and is the second link in the cardiac chain of survival.
In CPR, you need to keep the lungs working to get oxygen into the body. You need the heart to keep pumping blood.
Adrenaline is produced by the human body to give extra strength, stamina and speed of thought in times of need. Quite often it produces a sense of euphoria which people can crave, most commonly called an "adrenaline rush". Because of this drug like feeling it could possibly be called an adrenaline trip. However this may refer to someone actively seeking out stressful activities to produce this effect.