When is it nessessary to do CPR with chest compressions and without?Or is it nessessary to do compressions with every situation?
CPR (cardiopulmonary resuscitation) is done when a person (typically) has collapsed or is clearly in an emergency situation and the first-responder cannot detect a heartbeat. The purpose of CPR is to manually and artifically pump the heart to continue blood flow so vital organs do not shut down until professional help arrives. In addition to chest-compressions, CPR also often involves mouth-to-mouth resuscitation. This is done if the person is not breathing.
The only time chest-compressions would not be necessary is when the victim has a heart-beat, but is not breathing. In this situation the first-responder would simply perform what is called "rescue breathing." This provides oxygen to the body until professional help arrives. Of course, remember, depending on how long rescue breathing is performed, the heart beat should be periodically and regularly checked. If at any time, there ceases to be a pulse, chest compressions should be started.
Chest compressions are a vital step when performing cardiopulmonary resuscitation or CPR. The most updated guidelines for CPR from the American Heart Association include (and have always included) performing chest compressions. I have first hand knowledge of this because I just got re-certified as a CPR instructor a couple of weeks ago. Effective chest compressions are necessary to circulate blood to vital organs like the heart and brain.
If chest compressions are not being performed, first aid of some sort may be being rendered, but CPR is not being performed. A good example of this is acute respiratory failure. The person is either not breathing at all or the breathing is insufficient. In this scenario, the heart is still beating but respiration's are lacking. Rescue breathing could be done in that situation but chest compressions are not indicated.