Blood pressure is a fundamental indicator of cardiovascular health. It is often measured using a cuff and a stethoscope, a method known as auscultation, which provides both systolic and diastolic readings. However, palpated blood pressure measurement becomes a practical alternative when the standard approach is difficult or not possible.
Defining Palpated Blood Pressure
Palpated blood pressure estimates only the systolic blood pressure, which is the top number in a blood pressure reading. Unlike the auscultatory method that relies on listening for Korotkoff sounds with a stethoscope, palpation involves feeling for the return of a pulse. This tactile approach determines only the peak pressure when the heart contracts.
The absence of a diastolic reading, the bottom number representing the pressure in the arteries when the heart rests between beats, is a key characteristic of this method. Diastolic pressure is identified by the disappearance of Korotkoff sounds, which cannot be detected by touch. Therefore, a palpated blood pressure reading is always recorded as a single number followed by “palp” (e.g., 120/palp), indicating only the systolic pressure was obtained manually.
How Palpated Blood Pressure is Taken
Taking a palpated blood pressure begins with applying a blood pressure cuff to the upper arm. Next, the person performing the measurement locates a pulse, most commonly the radial pulse at the wrist, using their fingertips.
Once the pulse is located, the cuff is inflated rapidly until the radial pulse is no longer felt, signifying that the cuff pressure has temporarily stopped blood flow. The cuff is then inflated about 20 to 30 mmHg higher than the point where the pulse disappeared. The air is then slowly released from the cuff, typically at a rate of 2-3 mmHg per second, while the practitioner continues to feel for the radial pulse. The pressure reading on the gauge at the exact moment the pulse reappears is recorded as the systolic blood pressure. This method relies solely on the sense of touch.
When Palpation is Used
Palpated blood pressure measurement is particularly useful in specific scenarios where a full auscultatory reading is impractical or impossible. One common situation is in noisy environments, such as during an emergency in an ambulance or a crowded accident scene, where the sounds needed for a stethoscope reading would be obscured. In such conditions, feeling for a pulse provides a quick and reliable estimate of systolic pressure.
This method is also frequently employed in emergency situations when a rapid assessment is needed for a patient in critical condition. When a patient’s blood pressure is very low, the Korotkoff sounds might be too faint to hear with a stethoscope, making palpation a more effective way to determine at least the systolic pressure. Furthermore, if a stethoscope is unavailable, or as an initial rapid check before a more precise measurement, palpation serves as a valuable tool. While it only provides a systolic reading, having this information can be crucial for guiding immediate care and understanding a patient’s circulatory status.