Blood pressure measures the force blood exerts against artery walls, typically given as systolic (during heartbeats) and diastolic (between beats) numbers. While automated devices and stethoscope methods are common, palpation offers an alternative when these approaches are not feasible or traditional measurement is challenging.
Situations for Palpating Blood Pressure
Palpating blood pressure is valuable when traditional methods fall short. This includes noisy environments where stethoscope sounds are difficult to discern, or when a person has a very weak pulse or medical conditions make Korotkoff sounds hard to hear. Palpation is also employed in emergency settings for quickly obtaining a systolic pressure reading, or when only systolic pressure is required for assessment.
Step-by-Step Palpation Method
Have the person sit comfortably with their arm supported at heart level, palm upward. Select a blood pressure cuff that properly fits the upper arm; its bladder should cover at least 80% of the arm’s circumference. Position the cuff snugly on the bare upper arm, aligning the artery marker over the brachial artery, just above the elbow crease.
Locate the radial pulse on the same arm by gently placing your index and middle fingers over the radial artery on the thumb side of the wrist. You should feel a distinct, rhythmic throbbing. Close the valve on the cuff’s bulb and steadily inflate the cuff while continuously monitoring the radial pulse.
Continue inflating the cuff until the radial pulse disappears. After the pulse is no longer palpable, inflate the cuff an additional 20 to 30 millimeters of mercury (mmHg) beyond that point. This extra inflation ensures the artery is fully occluded and helps prevent an “auscultatory gap,” which can lead to an underestimation of systolic pressure.
Slowly deflate the cuff by gradually opening the valve at 2 to 3 mmHg per second. As the cuff deflates, pay close attention to the radial pulse. The point on the manometer where you first feel the radial pulse reappear is the systolic blood pressure reading. This is the only reading obtained through the palpation method.
Interpreting Palpated Pressure
The number obtained through palpation represents the systolic blood pressure, the peak pressure in the arteries when the heart contracts. Palpation does not provide a diastolic reading, which is the pressure when the heart is at rest between beats. Despite this limitation, knowing the systolic pressure can still offer valuable clinical information.
For adults, a normal systolic pressure is less than 120 mmHg. A systolic reading between 120 and 129 mmHg is considered elevated, suggesting an increased risk of developing high blood pressure. Readings of 130 mmHg or higher indicate hypertension. In emergency situations, a palpable systolic pressure provides a quick assessment of blood flow and perfusion to vital organs.
Ensuring Accurate Palpation
Achieving an accurate palpated blood pressure reading depends on several factors. Proper cuff placement and using the correct cuff size are important, as an ill-fitting cuff can lead to inaccurate results. The person’s position, ensuring they are relaxed and their arm is supported, also influences the reading; recent physical activity or caffeine intake can temporarily elevate blood pressure, so waiting a few minutes before measurement is advisable.
Common errors include deflating the cuff too rapidly, which can cause missing the point of pulse reappearance. Not waiting long enough between repeated measurements on the same arm yields inaccurate results; allow at least one to two minutes for blood flow to normalize. While palpation offers a useful snapshot, it is not a substitute for a complete blood pressure assessment by a healthcare professional, particularly for diagnosis or ongoing health monitoring.