"A" is for AIRWAY If the victim is drowsy and is not responsive, you need to make sure that his airway is clear of any blockage. The breaths may be thin and empty - look, listen and feelfor any signs of breathing. If you determine that the victim is not respiring, then something may be blocking his air passage. The tongue is the most natural airway blockage in an unconscious person.
To start CPR and first aid you will have to clear the choked air way of the victim. Lie the victim on his back on a flat surface with the help of one hand gently lift the head of the victim tilt it backward and lift the chin. This will force the tongue of the victim to shift away from the back of the throat leading to clear airway. This mechanism is known as "head tilt chin lift". Remove any object from the throat if present, if the victim do not start breathing on its own than give him artificial respiration.
If the victim is still not respiring on his own after the airway has been cleared, you will have to assist him breathing