The pulse is the rhythmic surge of blood felt as the heart pumps, reflecting the rate and strength of the body’s circulation. Assessing an infant’s pulse is a fundamental step in any emergency assessment, providing a rapid indication of the heart’s function and overall well-being. Because infants possess unique anatomical features, the standard site for checking circulation differs from that used for adults. For children under one year of age, the brachial pulse, located in the upper arm, is the most reliable and recommended location for this assessment.
Anatomy and Rationale for Using the Brachial Pulse
The brachial artery is a major blood vessel running along the inner side of the upper arm, extending from the armpit down toward the elbow. This vessel is considered the gold standard for checking an infant’s pulse because of its accessibility and reliability. In a baby, the brachial artery lies relatively close to the skin’s surface, making it easier to palpate and detect the pulsations compared to other sites.
Unlike adults, where the carotid pulse in the neck is commonly used, the carotid artery in an infant is often difficult to locate due to their shorter, thicker neck structure. Attempting to check the pulse in the neck of a small child also carries a risk of accidentally compressing their delicate airway. Similarly, the radial pulse at the wrist can be too faint and unreliable in infants, especially in emergency situations where circulation may be compromised.
Step-by-Step Guide to Finding and Measuring the Pulse
Begin by gently placing the infant on their back on a firm, flat surface. Then, slightly extend one of their arms with the palm facing upward. This positioning ensures the limb is relaxed and stable, allowing for an accurate assessment of the artery. The brachial artery is located on the inner arm, running down the groove between the bicep and tricep muscles.
To locate the pulse, use the pads of your index and middle fingers. Place them halfway between the infant’s shoulder and the crease of their elbow. It is important to avoid using your thumb for this process, as the thumb has its own strong pulse that can easily be mistaken for the infant’s heartbeat, leading to an inaccurate reading.
Apply a light, gentle pressure with your two fingers until you feel a distinct, rhythmic thumping beneath your fingertips. Applying excessive pressure is a common mistake that can completely compress the artery and make the pulse impossible to feel. Adjust your touch to be firm enough to detect the beat without occluding the flow.
Once the pulse is located, count the number of beats for a full 30 seconds, then multiply this figure by two to determine the beats per minute. In a stressful or emergency situation, you may check for a pulse for a shorter duration of 5 to 10 seconds.
Interpreting Infant Pulse Rates
The normal heart rate for an infant varies significantly based on their activity level, ranging from 100 to 160 beats per minute when awake and resting. This rate is naturally much faster than an adult’s and can increase further when the baby is crying, active, or has a fever. A sleeping infant’s heart rate will typically slow down, sometimes falling into the range of 90 to 160 beats per minute.
The strength and regularity of the pulse are just as informative as the rate itself, as a very weak or irregular pulse may suggest a problem with circulation. If the infant’s pulse is extremely fast, or if it is too rapid for you to count accurately, you should seek medical evaluation.
The most concerning finding is a heart rate that is significantly slow, specifically if it is below 60 beats per minute. If the pulse rate falls below 60 beats per minute and the infant shows signs of poor perfusion, such as paleness or a bluish tint to the skin, immediate action is necessary. This slow rate indicates a potential circulatory failure, and standard first aid protocols require beginning cardiopulmonary resuscitation (CPR). In any situation where the pulse is absent, extremely weak, or falls into the dangerously low range, you must call for emergency medical services immediately.