Cardiopulmonary Resuscitation (CPR) is an emergency procedure performed when a person’s breathing or heart stops. CPR involves chest compressions and rescue breaths to keep oxygenated blood flowing to the brain and other vital organs until professional medical help arrives. Knowing the precise physical technique, particularly where to place the hands, is fundamental to performing effective CPR.
Anatomical Target for Adult Chest Compressions
The specific target for adult chest compressions is the center of the chest, directly over the breastbone (sternum). This location allows the heart to be compressed between the sternum and the spine, effectively circulating blood. To locate this spot, use the imaginary line drawn between the person’s nipples. The heel of the hand should be placed on the lower half of the sternum, just below the center point of that line.
The sternum is a flat bone that protects the heart and lungs, making it the strongest point for applying pressure during CPR. Compressions must be delivered only on the sternum and not on the surrounding ribs. Placing pressure directly on the ribs increases the risk of causing fractures.
Hand Positioning and Mechanics for Effective Compression
Once the correct location is identified, the heel of one hand is placed directly on the lower half of the sternum. The second hand is placed immediately on top of the first, with the fingers interlaced or lifted off the chest. This stacking ensures the force is concentrated through the heel of the bottom hand. Lifting the fingers prevents pressure from being applied to the ribs.
The rescuer should position their body so that their shoulders are directly above their hands, with arms kept straight and elbows locked. This posture allows the rescuer to use their entire upper body weight, rather than just arm strength, to deliver the necessary force.
For an adult, compressions must be delivered to a depth of at least 2 inches (5 centimeters) but not more than 2.4 inches (6 centimeters). The compressions must be delivered at a rapid and consistent rate of 100 to 120 per minute. After each compression, the rescuer must allow the chest to fully recoil without leaning on it, which permits the heart to refill with blood.
Modified Placement for Children and Infants
Hand placement and the force of compressions must be modified when performing CPR on children and infants. The fundamental location remains the center of the chest, over the sternum, but the technique for applying pressure changes significantly.
For children between the ages of one year and puberty, compressions are delivered to the center of the chest, generally using the heel of one hand. Depending on the child’s size, two hands may be used to achieve the correct depth of about two inches (5 centimeters). Using only one hand for smaller children helps control the amount of force applied.
Infants under the age of one year require a significant modification in technique. Compressions are performed using two fingers, typically the index and middle fingers, placed on the sternum just below the nipple line. The required compression depth is gentler, aiming for about 1.5 inches (4 centimeters). Alternatively, a trained rescuer may use the two-thumb encircling technique, placing both thumbs on the sternum while the hands wrap around the infant’s chest to support the back.