53 y.o. suddenly collapses and becomes unresponsive. You witness him collapse and are the first rescuer to arrive at the scene. You find him motionless on the floor. Several rescuers respond, you ask them to activate the emergency response and retrieve the AED and emergency equipment. As you check for a pulse and breathing, you notice that the man is gasping for air and making 'snorting' sounds. You do not feel a pulse. What is your best next action?
1) Begin CPR with chest compressions
2) Open the airway and give rescue breaths
3) Wait for the AED to arrive
4) Call for additional help