Blood pressure measurements are typically given as two numbers, but sometimes they appear with the abbreviation “palp” instead of the second number, such as “90 over palp.” This notation is a specialized shorthand used by healthcare professionals to provide a time-sensitive, incomplete, but highly informative reading of a patient’s circulatory status. Understanding this specific measurement requires knowing how blood pressure is recorded, why the second number is missing, and what the number 90 indicates. This article explains the meaning behind this notation, which is often associated with urgent medical situations.
Decoding the Blood Pressure Notation
A standard blood pressure reading, like 120/80, consists of two distinct measurements. The first number, 120, is the systolic blood pressure (SBP), which represents the maximum pressure in the arteries when the heart contracts and pushes blood out. The second number, 80, is the diastolic blood pressure (DBP), reflecting the pressure in the arteries when the heart rests between beats.
The notation “90 over palp” substitutes the diastolic number with the term “palp,” an abbreviation for palpation, or measurement by touch. Palpation is a technique used to find the systolic pressure by feeling for a pulse as the blood pressure cuff is deflated. This method cannot reliably determine the diastolic pressure.
The blood pressure cuff is inflated until the pulse disappears, then slowly released while a finger remains on the radial artery at the wrist. The moment the pulse is first felt returning corresponds to the systolic pressure, which in this case is 90 millimeters of mercury (mmHg). Since the technique relies on a physical pulse returning, it captures the peak pressure from the heart’s contraction but offers no information on the resting pressure between beats.
When and Why Palpation is Used
The most common method for measuring blood pressure is auscultation, which involves listening for specific sounds, called Korotkoff sounds, using a stethoscope. This standard method yields both the systolic and diastolic pressures, as the sounds disappear completely once the pressure drops below the diastolic level. Palpation is not the primary method but is used in specific, often time-sensitive, scenarios.
Healthcare providers use the palpation method when the environment is too noisy to clearly hear the Korotkoff sounds, such as in a moving ambulance or a chaotic emergency room. Palpation is also quicker to perform than auscultation, making it useful in situations where speed is necessary to get a rapid assessment of a patient’s condition.
The most common reason for documenting a reading as “/palp” is when the patient’s blood pressure is exceptionally low (hypotension). In cases of significant hypotension, the Korotkoff sounds may be too faint to hear, or the diastolic pressure may be too low to be reliably determined by listening. Palpation provides a necessary fallback, offering a quick, if incomplete, systolic reading to guide the initial medical response.
What a Systolic Pressure of 90 Signifies
A systolic blood pressure of 90 mmHg, especially when recorded via palpation, signals concern and indicates low blood pressure (hypotension). While a single low reading may be normal for some individuals, 90 systolic is generally considered below the healthy range for adults, which is typically above 90/60 mmHg. In the context of a palpated reading, this low number is frequently an urgent finding.
When a healthcare provider resorts to palpation, it often suggests the patient is in a compromised state, possibly experiencing trauma, severe dehydration, or shock. A systolic pressure of 90 mmHg is close to the threshold where the body may not be able to effectively perfuse vital organs like the brain and kidneys. If a patient shows signs of confusion, rapid heart rate, or cool, clammy skin alongside this low pressure, it suggests the body is struggling to compensate.
The finding of “90 over palp” serves as an immediate alert that the patient’s circulatory system is under stress and requires prompt medical attention and monitoring. This measurement provides the fastest available data point for systolic pressure, allowing medical teams to quickly implement supportive care.