The human pulse is the tangible wave of blood flow that travels through the arteries, generated by the heart’s forceful contractions. Assessing this pulse provides immediate, non-invasive information about a person’s heart rate, rhythm, and overall circulatory function. It is a foundational tool in health assessment, serving as a direct messenger for the cardiovascular system’s performance. While the pulse can be checked at several sites, the carotid and brachial arteries are two major locations, each offering unique advantages depending on the assessment goal.
Anatomical Placement and Accessibility
The carotid pulse is located in the neck, situated in the groove between the trachea (windpipe) and the large sternocleidomastoid muscle. To locate it, one gently presses two fingers just beside the windpipe and below the jawline. This central location makes the carotid artery readily accessible, particularly in an unresponsive person, without the need to remove clothing.
Conversely, the brachial pulse is found along the inner side of the upper arm, between the elbow and the shoulder. Clinicians locate it by feeling for the bicep tendon near the antecubital fossa (the inner crease of the elbow). The pads of the fingers are then placed about two centimeters medial to the tendon and pressed firmly to detect the pulse.
Physiological Differences in Pulse Assessment
The carotid artery is a large, central vessel that supplies blood to the brain and is close to the heart. Its pulse is typically strong and reflects the core circulatory status. Because of its size and proximity to the heart, the carotid pulse is one of the last pulses to disappear during severe shock or a significant drop in blood pressure. A palpable carotid pulse suggests the patient’s systolic blood pressure is at least 60 millimeters of mercury (mmHg), a rough indicator of perfusion.
The brachial artery is considered a more peripheral artery compared to the carotid. The characteristics of the pulse wave change as it travels farther from the heart. The brachial pulse is less indicative of immediate central cardiac output compared to the carotid pulse, but it provides valuable information about the integrity of blood flow to the arm.
Application in Emergency and Medical Contexts
The carotid pulse is the preferred site for checking circulation in an unresponsive adult or child according to cardiopulmonary resuscitation (CPR) guidelines. Its reliability and strong amplitude make it the most logical starting point for determining if a patient has a pulse at all. Rescuers are taught to check for the carotid pulse for no more than ten seconds before initiating chest compressions if no pulse is found. The carotid pulse should never be palpated on both sides of the neck simultaneously, as this can compromise blood flow to the brain.
The brachial pulse holds a distinct role in specific medical assessments, particularly for infants. In newborns and babies, the shorter neck and common presence of fat deposits can make locating the carotid pulse challenging and unreliable. Therefore, the brachial artery is the standard site for checking the pulse in an infant during a medical emergency. The brachial artery is also the required location for performing a manual blood pressure measurement using a stethoscope and cuff.