CPR begins by assessing the safety of the environment, placing the patient on a flat surface or hard bed, fully exposing the patient’s thorax, and determining within 10 seconds whether the patient is in cardiac arrest by judging the loss of consciousness, respiratory arrest and loss of aortic pulsation, and if so, immediately beginning CPR. The steps of CPR include cardiac compressions, airway opening and artificial respiration. The location of cardiac compressions is in the middle and lower 1/3 of the sternum, with both hands crossed, using the large and small fissure as the pressure point, and pressing vertically downward, with a depth of 5-6 cm and a frequency of 100-120 compressions/min. Then open the airway and gently lift the patient’s jaw so that the line between the angle of the jaw and the earlobe is perpendicular to the ground. Artificial respiration is performed by pinching the patient’s nasal cavity and blowing forcefully mouth-to-mouth, and seeing a rise and fall of the thorax indicates successful artificial respiration.