Blood Pressure (Systolic): Palpation (Home Health Care) - CE/NCPD
OVERVIEW
Blood pressure (BP) is the force exerted by blood against the vessel walls. During a normal cardiac cycle, BP reaches a peak, followed by a trough. Peak pressure occurs when the heart’s ventricular contraction, or systole, forces blood under high pressure into the aorta. When the ventricles relax, the blood remaining in the arteries exerts a trough, or diastolic, pressure against the arterial wall. Diastolic pressure is the minimum pressure exerted against the arterial wall.
Patients at risk for alterations in BP measurement include those who have:
- Circulatory shock (hypovolemic, septic, cardiogenic, or neurogenic)
- Acute or chronic pain
- Rapid IV infusion of fluids or blood products
- Increased intracranial pressure
- Postoperative status
- Preeclampsia of pregnancy
The standard unit for measuring BP is millimeters of mercury (mm Hg). The measurement indicates the height to which BP can sustain the column of mercury.
The most common methods for measuring BP are auscultation, using a sphygmomanometer and a stethoscope, and measurement using an electronic BP monitor. Palpation may be used to obtain an estimate of systolic BP before using the auscultation method, or if unable to obtain a BP by auscultation.
During auscultation, as the sphygmomanometer cuff is deflated, five different sounds, called Korotkoff sounds, are heard over the artery. Each sound has a distinct characteristic (Figure 1). BP is recorded with the first Korotkoff sound (systolic pressure reading) and at the beginning of the fifth Korotkoff sound (diastolic pressure reading). The difference between systolic pressure and diastolic pressure is the pulse pressure. For a BP of 120/80 mm Hg, the pulse pressure is 40 mm Hg, the difference between 120 mm Hg and 80 mm Hg.
Cuff size should be proportionate to the limb circumference. Most adults require a large adult cuff. The correct cuff size is especially important for obtaining accurate readings in pediatric patients and patients with obesity.undefined#ref7">7 An improper-size cuff can produce an inaccurate BP measurement. Using a cuff that is too narrow results in an overestimation of BP, whereas using a cuff that is too wide results in an underestimation of BP.1,6
When measuring BP in the upper arm is not possible—for example, when the available BP cuffs do not fit the upper arm properly—BP may be measured in the forearm. To obtain the most accurate reading, the proper-size BP cuff must be used for the forearm, which typically has a smaller circumference than the upper arm. BP measurements in the forearm and upper arm are not interchangeable. Systolic BP readings tend to be higher in more distal arteries, such as those in the forearm.8 The thigh or lower calf or ankle can be used if measurement of the upper arms and forearms is not possible.9 Ankle BP is clinically effective in diagnosing hypertension when the upper arm is not available for proper cuff placement.8
SUPPLIES
See Supplies tab at the top of the page.
EDUCATION
- Provide developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, and overall neurologic and psychosocial state.
- Explain how the equipment works as well as the procedure to the patient, family, and caregivers.
- Instruct the patient, family, and caregivers about ambulatory BP threshold guidelines. In adults, normal BP is less than 120/80 mm Hg3,4 (Table 1).
- Educate the patient, family, and caregivers about the signs and symptoms of hypotension:
- Dizziness or light-headedness
- Fainting (syncope)
- Blurred vision
- Nausea
- Fatigue
- Lack of concentration
- Educate the patient, family, and caregivers about the risk factors for hypertension:
- Family history of hypertension, premature heart disease, lipidemia, or renal disease
- Obesity
- Cigarette smoking
- Vaping
- Heavy alcohol consumption
- High blood cholesterol and triglyceride levels
- Prolonged stress from psychosocial and environmental factors
- Sedentary lifestyle
- Educate the patient, family, and caregivers regarding the primary strategies for preventing hypertension:4
- Managing weight
- Engaging in daily exercise
- Limiting sodium and saturated fat in the diet
- Maintaining adequate intake of dietary potassium and calcium
- Taking medication as prescribed
- Limiting alcohol intake
- Avoiding tobacco products
- Instruct the patient, family, and caregivers to ensure that the patient has adequate rest before BP measurements and that BP measurements are performed at the same time each day using the same limb with the patient in the same position, either sitting or lying down.
- Explain to the family and caregivers that the patient must remain still and quiet during the procedure.
- Encourage questions and answer them as they arise.
PROCEDURE
- Perform hand hygiene and don gloves. Don additional personal protective equipment (PPE) based on the patient’s need for isolation precautions or the risk of exposure to bodily fluids.
- Introduce yourself to the patient, family, and caregivers.
- Verify the correct patient using two identifiers.
- Explain the procedure to the patient, family, and caregivers and ensure that the patient agrees to treatment.
- Verify the practitioner’s order and assess the patient for pain.
- Prepare an area in a clean, convenient location and assemble the necessary supplies.
- Review the patient’s medical record for a history of cardiovascular disease, renal disease, diabetes, chronic pain, and other factors that may influence BP (e.g., weight, smoking, medications).
- Evaluate the patient for signs and symptoms of BP alterations.
- Observe a patient at risk for high BP for:
- Headache (usually occipital)
- Facial flushing
- Nosebleed
- Fatigue
- Observe a patient at risk for low BP for:
- Dizziness
- Mental confusion
- Restlessness
- Pale, dusky, or cyanotic skin and mucous membranes
- Cool, mottled skin over the extremities
- Determine the best site for BP measurement. Consider using the lower extremity if the brachial arteries are inaccessible. Avoid applying the cuff to an extremity in these situations:
- A peripherally inserted central catheter is present.
- An arteriovenous shunt or fistula is present.
- An ipsilateral (same-side) breast or axillary surgery has been performed. The postsurgical side may be used if other sites are not available or practical, because the risk of developing lymphedema from occasional BP measurement following breast or lymph surgery is low.5
- The extremity has been traumatized or injured.
- The extremity has known infections or medical conditions (e.g., those causing vasoconstriction or a tumor pressing on the vascular supply).
- The extremity has a cast or bulky bandage.
- Determine the previous baseline BP and site, if available, from the patient’s record.
- Make sure the patient has not exercised, ingested caffeine, or smoked immediately before obtaining the BP measurement.4 Make sure the patient does not have to void.
Rationale: A full bladder increases pressure on the kidneys and can increase BP.
- Make sure the room is warm, approximately 72°F/22-23°C.6
Rationale: Exposure to cold can increase systolic BP.6
- Measure the extremity circumference and select the appropriate-size cuff (Figure 2) (Table 2).
Rationale: Proper cuff size is necessary for an accurate reading. The cuff must be wide and long enough to allow for the size of the arm or thigh. Narrow cuff can cause an artificially high reading.
- Tell the patient that BP is going to be taken and that the cuff will squeeze the arm or leg.
- Have the patient sit or lie down. If the patient is sitting, ensure that the patient’s back is supported.
- If using the upper arm or forearm:
- Position the patient’s arm, supported, at heart level with the palm facing up (Figure 3).
- If the patient is sitting, instruct the patient to keep feet flat on the floor with the legs uncrossed.
Rationale: If the patient’s arm is not supported at the heart level, a lower BP will be recorded when the arm is above heart level, and a higher BP will be recorded when the arm is below the heart level.6 Leg crossing can increase systolic and diastolic BP.
- If the patient is supine, ensure that the legs are not crossed.
Rationale: Leg crossing can falsely increase systolic and diastolic BP.6
- If using the leg:
- Assist the patient to a prone position.
- If the patient is unable to assume a prone position, assist the patient to a supine position with the knee slightly flexed.
Rationale: The prone position provides the best access to the popliteal artery.
- Ask the patient not to cross the legs.
- Expose the patient’s arm or leg fully by removing any constricting clothing. Do not place the BP cuff over clothing.
Rationale: Placing the cuff over clothing may affect the BP measurement.
- Apply the BP cuff to the patient’s arm or leg. Do not place the cuff over a bony prominence, nerve, or joint.6
- Upper arm
- Palpate the brachial artery for a pulse (Figure 4).
- Apply the cuff in the middle of the patient’s arm approximately midpoint with the patient’s sternum, and center the arrows marked on the cuff over the brachial artery.6 If the cuff has no center arrows, estimate the center of the bladder and place it over the artery.
Rationale: Positioning the cuff bladder directly over the brachial artery ensures that proper pressure is applied during inflation.
- Wrap the fully deflated cuff evenly and snugly around the patient’s upper arm.
Rationale: A loose-fitting cuff can cause an artificially high reading.
- Forearm
- Palpate the radial artery for a pulse.
- Position the cuff below the antecubital fossa.
- Apply the cuff by centering arrows marked on the cuff over the radial artery and below the antecubital fossa.6 If the cuff has no center arrows, estimate the center of the bladder and place it over the artery.
Rationale: Positioning the cuff bladder directly over the radial artery ensures that proper pressure is applied during inflation.
- Wrap the fully deflated cuff evenly and snugly around the patient’s forearm.
Rationale: A loose-fitting cuff can cause an artificially high reading.
- Thigh
- Palpate the popliteal artery for a pulse.
- Position the cuff over the lower third of the patient’s thigh.6
- Apply the cuff by centering the arrows marked on the cuff over the popliteal artery and above the popliteal fossa.6 If the cuff has no center arrows, estimate the center of the bladder and place it over the artery.
Rationale: Positioning the cuff bladder directly over the popliteal artery ensures that proper pressure is applied during inflation.
- Wrap the fully deflated cuff evenly and snugly around the patient’s thigh.
Rationale: A loose-fitting cuff can cause an artificially high reading.
- Lower calf or ankle
- Palpate the dorsalis pedis or posterior tibial artery for a pulse.
- Position the cuff over the lower half of the patient’s calf.9
- Apply the cuff to the lower calf and above the malleoli.9
- Secure the deflated cuff evenly and snugly around the lower calf and above the malleoli.
- Position the manometer vertically at eye level.
Rationale: Looking up or down at the scale can result in distorted incorrect readings.
- Ask the patient not to speak while BP is being measured.
- Locate and continually palpate the brachial artery (upper arm BP), radial artery (forearm BP), popliteal artery (thigh BP), or dorsalis pedis or posterior tibial artery (calf BP) with the fingertips of one hand (Figure 4).
- Palpate the artery distal to the cuff with the fingertips of the nondominant hand while inflating the cuff rapidly to a pressure level above the point at which the pulse disappears.
- Slowly release the pressure bulb valve, allowing the manometer needle to fall slowly and continuously at a rate of 2 to 3 mm Hg per second.6
- Note the point on the manometer at which the pulse reappears. This point is the palpated estimate of systolic BP.
Rationale: Too rapid a decline in the mercury level causes an inaccurate measurement. Too slow a decline in the mercury level causes discomfort.
- Deflate the cuff fully and wait a short time.
Rationale: The estimate of systolic BP determines the maximal inflation point for accurate reading by palpation. Completely deflating the cuff prevents venous congestion and false high readings.
- Remove the cuff from the patient’s arm or leg unless a repeat measurement is needed (after a brief pause).
Rationale: Continuous cuff inflation can cause arterial occlusion, resulting in numbness and tingling of the arm or leg.
- If this is the patient’s first BP measurement, repeat the procedure on the other arm or leg. If there is a consistent difference between the BP in the patient’s arms or between the BP in the patient’s legs, use the arm or leg with the higher pressure per the organization’s practice or the patient’s condition.1,7
Rationale: Comparison of BP in both arms or legs helps detect cardiovascular, neurologic, and musculoskeletal abnormalities. A normal difference of up to 10 mm Hg may exist between arms.6
- Help the patient resume a comfortable position and return any removed clothing. Inform the patient of the BP reading, as appropriate.
- Record abnormal values and report them to the practitioner (Table 1).
- Clean the BP cuff per the manufacturer’s instructions and the organization’s practice.
- If obtaining a patient’s BP measurement for the first time, establish the BP reading as the baseline if it is within the acceptable range per the organization’s practice.
- Compare the BP reading with the patient’s previous baseline, if available, and the usual BP for the patient’s age.
- Discard or store supplies, remove PPE, and perform hand hygiene.
- Document the procedure in the patient’s record.
EXPECTED OUTCOMES
- BP is within acceptable range.
- Patient tolerates procedure.
- Palpable pulses can be obtained.
UNEXPECTED OUTCOMES
- BP is above acceptable range.
- BP is below acceptable range or insufficient for adequate perfusion and oxygenation of tissues.
- Palpable pulses cannot be obtained.
- BP reading cannot be obtained.
- A significant difference exists between upper extremity BP readings or between lower extremity BP readings.
DOCUMENTATION
- BP measurement
- Method used to obtain BP
- Site of BP measurement and patient’s position
- Abnormal findings
- Education
- Patient’s progress toward goals
- Unexpected outcomes and related interventions
- Assessment of pain, treatment if necessary, and reassessment
OLDER ADULT CONSIDERATIONS
- Older adults, especially frail older adults, typically have lost upper arm mass, requiring special attention to BP cuff size.
- Older adults’ skin is more fragile and susceptible to damage from cuff pressure when BP measurements are frequent. More frequent evaluation of the skin under the cuff or rotation of BP sites is recommended.
- Older adults have increased systolic pressure because of decreased vessel elasticity.
- Older adults often experience a fall in BP after eating.
- Older adults need to change position slowly and to wait after each change to avoid postural hypotension and prevent injuries.
- American Association of Critical-Care Nurses (AACN). (2016, reviewed 2021). AACN practice alert: Obtaining accurate noninvasive blood pressure measurements in adults. Critical Care Nurse, 36(3), e12-e16. doi:10.4037/ccn2016590
- American Heart Association (AHA). (2024). Home Blood Pressure Monitoring. Retrieved July 2, 2024, from https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings/monitoring-your-blood-pressure-at-home#.Wuct7ExFwy9
- American Heart Association (AHA). (2024). Understanding blood pressure readings. Retrieved July 2, 2024, from https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings#.Wucr9UxFwy9
- American Heart Association (AHA). (2024). How to Manage High Blood Pressure. Retrieved July 2, 2024, from https://www.heart.org/en/health-topics/high-blood-pressure/changes-you-can-make-to-manage-high-blood-pressure
- McLaughlin, S.A. and others. (2017). Considerations for clinicians in the diagnosis, prevention, and treatment of breast cancer-related lymphedema, recommendations from an expert panel: Part 2: Preventive and therapeutic options. Annals of Surgical Oncology, 24(10), 2827-2835. doi:10.1245/s10434-017-5964-6
- Muntner, P. and others. (2019). Measurement of blood pressure in humans: A scientific statement from the American Heart Association. Hypertension, 73(5), e35-e66. doi:10.1161/HYP.0000000000000087
- Pickering, T.G. and others. (2005). Recommendations for blood pressure measurement in humans and experimental animals. Part 1: Blood pressure measurement in humans: A statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Hypertension, 45(1), 142-161. doi:10.1161/01.HYP.0000150859.47929.8e Retrieved July 2, 2024, from https://www.ahajournals.org/doi/full/10.1161/01.CIR.0000154900.76284.F6#d1e1300
- Sheppard, J. and others. (2019). Defining the relationship between arm and leg blood pressure readings: A systematic review and meta-analysis. Journal of Hypertension, 37(4), 660-670. doi:10.1097/HJH.0000000000001958
- Sheppard, J. and others. (2020). Measurement of blood pressure in the leg—A statement on behalf of the British and Irish Hypertension Society. Journal of Human Hypertension, 34(6), 418-419. doi:10.1038/s41371-020-0325-5
ADDITIONAL READINGS
Li, Y. and others. (2020). Effect of cuff positioning on the accuracy of blood pressure measurement with automated electronic blood pressure monitors. Journal of Clinical Hypertension 22(7), 1163-1172. doi:10.1111/jch.13902
Clinical Review: Martha Beck, MA, BSN, RN, CNOR
Published: August 2024