The two-thumb encircling technique is a specialized method of chest compression used during cardiopulmonary resuscitation (CPR). This technique leverages the unique anatomy of very small patients to maximize the effectiveness of blood circulation. It is designed to provide high-quality compressions while minimizing the risk of injury to fragile structures.
Defining the Target Age Group
The two-thumb encircling technique is designated as the preferred method for performing chest compressions on an infant during a cardiac emergency. In the context of resuscitation guidelines, an infant is generally defined as a victim from birth up to one year of age.
This technique is the consensus recommendation from major resuscitation councils, such as the American Heart Association (AHA). It is particularly recommended when two or more rescuers are present. While the two-finger technique is often recommended for a single rescuer, the two-thumb encircling method is considered biomechanically superior for delivering consistent, high-quality compressions.
Anatomical Rationale for This Approach
The superior efficacy of the two-thumb encircling method is rooted in the unique anatomical structure of an infant’s chest. The technique provides a circumferential squeeze, engaging both the sternum and the lateral sides of the rib cage simultaneously. This action generates a higher peak systolic blood pressure and coronary perfusion pressure compared to the two-finger technique. This results in significantly better blood flow to the heart and other vital organs.
By encircling the chest with the hands, the rescuer’s fingers provide support to the infant’s back and sides, which helps to stabilize the victim on the firm surface. This stability is important for achieving the correct compression depth and reduces the risk of accidental injury to the delicate rib cage and underlying abdominal organs. The mechanical advantage of using the thumbs allows the rescuer to maintain adequate compression depth with less effort, which also helps to reduce rescuer fatigue during prolonged resuscitation efforts.
Execution of the Two-Thumb Technique
The proper execution of the two-thumb encircling technique begins with positioning the infant on a firm, flat surface. The rescuer stands or kneels at the infant’s feet, allowing both hands to comfortably encircle the chest. The fingers of both hands are spread and used to cradle the infant’s back, providing firm counter-pressure and stability.
The two thumbs are placed side-by-side on the lower half of the breastbone (sternum), specifically just below the imaginary line connecting the infant’s nipples. It is important to avoid placing pressure on the very bottom tip of the sternum, known as the xiphoid process, as this can cause injury. Compressions are then delivered straight down, pressing the sternum to a depth of approximately 1.5 inches (about 4 centimeters).
The compressions must be delivered at a consistent rate of 100 to 120 compressions per minute. After each compression, it is crucial to allow the chest to fully recoil back to its normal position before the next compression is delivered. This full recoil allows the heart to refill with blood, making the next compression effective.
Techniques for Older Children and Adults
The specialized two-thumb encircling technique is strictly limited to infants because a larger victim’s anatomy requires a different force application. Once a child is older than one year of age, or exhibits signs of puberty, the technique shifts to methods that accommodate their larger body size and more developed chest wall.
Techniques for Children
For children typically between the ages of one year and the onset of puberty, the standard compression method involves using the heel of one hand placed on the center of the chest. In larger children, the rescuer may need to use two hands to achieve the necessary compression depth. The required compression depth for a child is greater than for an infant, typically about two inches or one-third the depth of the chest.
Techniques for Adolescents and Adults
For adolescents and adults, the standard technique involves using the heel of two hands stacked and interlaced. The rescuer’s shoulders are positioned directly over their hands to press down at least two inches, but no more than 2.4 inches, to effectively circulate blood. The compression rate of 100 to 120 per minute remains consistent across all age groups, but the hand placement and depth are adjusted to match the victim’s size and structure.