26. CCA Study Notes: Measuring, Assessing, and Reporting Blood Pressure

The Big Picture

Blood pressure tells you how much force blood places against the walls of an artery. A blood pressure reading has two numbers. The top number relates to the heart contracting, and the bottom number relates to the heart resting between contractions.

Accurate readings depend on the right equipment, the right cuff size, correct client positioning, a quiet setting, and following the procedure in the proper order.

A support worker must also know their role. Employer policy, job description, training, supervision, reporting requirements, and the client’s care plan all matter when blood pressure measurement forms part of the worker’s duties.

Look for Nova Scotia CCA Notes throughout this page for current provincial guidance.

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Course Notes: Key Ideas You Need to Know

What Blood Pressure Means

Blood pressure is the amount of force blood exerts against the walls of an artery.

Three things influence blood pressure:

• The force of the heart’s contractions
• The amount of blood pumped with each heartbeat
• How easily blood moves through the blood vessels

Systole and Diastole

The heart goes through periods of contraction and relaxation.

Systole is the period when the heart muscle contracts.

Diastole is the period when the heart muscle relaxes.

Blood pressure measurement includes both periods.

Systolic pressure is the higher pressure. It represents the force required to pump blood from the heart into the arterial circulation ⓘ.

Diastolic pressure is the lower pressure. It represents the pressure in the arteries while the heart rests.

How a Blood Pressure Reading Is Written

Blood pressure uses millimetres of mercury, written as mm Hg.

The systolic pressure appears first, over the diastolic pressure.

An average adult reading is:

120/80 mm Hg

In this reading:

• 120 mm Hg is the systolic pressure.
• 80 mm Hg is the diastolic pressure.

Blood Pressure Ranges

Blood pressure changes easily and sometimes changes from minute to minute.

The listed normal ranges are:

Pressure	Normal Range
Systolic	100 to 140 mm Hg
Diastolic	60 to 90 mm Hg

Another stated reference point is that normal blood pressure is below 120/80 mm Hg.

Hypertension means persistent blood pressure measurements above the normal systolic pressure of 140 mm Hg or the normal diastolic pressure of 90 mm Hg.

Blood pressure consistently above 140/90 mm Hg is considered high. For clients with diabetes, 130/80 mm Hg is considered high.

Hypotension is a condition in which systolic blood pressure is below 90 mm Hg and diastolic blood pressure is below 60 mm Hg. These low readings must be reported.

Low blood pressure is normal for some clients. Hypotension may also signal a life-threatening problem.

Readings That Need Immediate Reporting

For young and middle-aged adults:

• Report systolic pressure above 140 mm Hg at once.
• Report diastolic pressure above 90 mm Hg at once.
• Report systolic pressure below 90 mm Hg.
• Report diastolic pressure below 60 mm Hg.

More broadly, know the client’s normal blood pressure range. Immediately report any measurement above or below that client’s normal range.

Blood Pressure and Age

Blood pressure changes with age.

Age	Blood Pressure Information
Infant	Systolic 65 to 115 mm Hg, diastolic 42 to 80 mm Hg
7 years	Systolic 87 to 117 mm Hg, diastolic 48 to 64 mm Hg
14 to 17 years	Blood pressure varies according to body size
Adult	Average blood pressure is 120/80 mm Hg

Blood pressure above 140/90 mm Hg is defined as hypertension in the adult information provided.

Infants and Children

Infants and children normally have lower blood pressure readings than adults.

A newborn’s blood pressure is usually about 70/55 mm Hg.

By 1 year of age, blood pressure rises to about 90/55 mm Hg. It continues to rise as the child grows.

Adult blood pressure levels are reached between 14 and 18 years of age.

Role limit: Measuring blood pressure in infants and children is beyond a support worker’s scope of practice. This task is the responsibility of a nurse.

Older Persons

As people age, arteries narrow and lose elasticity. The heart then works harder to move blood through the vessels.

Both systolic and diastolic pressures are therefore higher in older people. A blood pressure of 160/90 mm Hg is considered normal for most older persons.

Older people are also at risk for orthostatic hypotension.

Factors That Affect Blood Pressure

Many factors influence blood pressure.

Age

Blood pressure rises with age. It is lowest during infancy and childhood and highest during adulthood.

Gender

Women usually have lower blood pressure than men. Blood pressure tends to rise in women after menopause.

Blood Volume

Blood volume means the amount of blood in the system.

Severe bleeding lowers blood volume and blood pressure.

Rapidly giving intravenous, or IV, fluids increases blood volume and raises blood pressure.

Stress

Stress, anxiety, fear, and other emotions increase blood pressure as the body responds.

Pain

Pain generally increases blood pressure.

Severe pain may lead to shock, which seriously lowers blood pressure.

Exercise

Physical activity increases blood pressure.

Do not measure blood pressure immediately after exercise.

Weight

Blood pressure is higher in people who are overweight. Weight loss lowers blood pressure.

Ethnicity

Blood pressure tends to be higher among Canadians of South Asian, Indigenous, or African descent.

Diet

A high-sodium diet increases the amount of water in the body. The increased fluid volume raises blood pressure.

Medications

Some medications raise blood pressure. Others lower it.

Other medications produce high or low blood pressure as an adverse effect.

Position

In clients taking blood pressure medication, blood pressure may be lower while lying down and higher while standing.

Sudden changes in position sometimes produce sudden changes in blood pressure.

Orthostatic hypotension occurs when blood pressure drops rapidly after a person stands suddenly. The person may experience dizziness and fainting.

Smoking

Smoking increases blood pressure.

Nicotine causes blood vessels to narrow. The heart then works harder to move blood through those narrowed vessels.

Alcohol

Excessive alcohol intake raises blood pressure.

Equipment Used to Measure Blood Pressure

Before using blood pressure equipment:

• Make sure you received proper training.
• Follow the manufacturer’s instructions.
• Follow employer policy.

The main equipment for manual blood pressure measurement includes a sphygmomanometer and a stethoscope.

Sphygmomanometer

A sphygmomanometer is an instrument used to measure blood pressure.

It includes:

• A blood pressure cuff
• A measuring device called a manometer

Some provinces and territories allow support workers to use only electronic blood pressure machines.

There are three types of manometers.

Aneroid Manometer

An aneroid manometer has a round dial with a needle that points to calibrated measurements.

Aneroid manometers may be used in all settings.

Mercury Manometer

A mercury manometer contains a column of mercury inside a calibrated tube.

Mercury is hazardous.

If a mercury manometer breaks:

1. Call your supervisor at once.
2. Do not touch the mercury.
3. Do not allow the client to touch the mercury.
4. Remove the client from the area if possible.
5. The facility or agency must follow its special procedures for hazardous materials.

Electronic Manometer

An electronic manometer displays the blood pressure reading automatically.

It usually also displays the pulse rate.

Some models inflate and deflate the cuff automatically. Other models provide automatic deflation only.

Electronic manometers are common in facilities and are also available for home use.

How the Blood Pressure Cuff Works

The cuff wraps around the client’s upper arm.

A tube connects the cuff to the manometer. Another tube connects the cuff to a small handheld bulb.

Squeezing the bulb inflates the cuff when the valve is set for inflation. The inflated cuff places pressure over the brachial artery.

Turning the valve in the other direction deflates the cuff. Blood pressure is measured as the cuff deflates.

Cuff Size Matters

Use the correct cuff size for an accurate reading.

A client with a very small arm may need a pediatric cuff. A client with a very large arm may need an extra-large cuff.

A loose or incorrectly sized cuff affects accuracy.

Stethoscope

A stethoscope is an instrument used to listen to sounds from the heart, lungs, and other body organs. It makes those sounds easier to hear.

During manual blood pressure measurement, the stethoscope picks up sounds from blood moving through the brachial artery as the cuff deflates.

Electronic sphygmomanometers do not require a stethoscope.

Using a Stethoscope Safely and Correctly

Stethoscopes touch the skin of different clients and health care team members. Cleaning helps prevent the spread of microbes.

When using a stethoscope for blood pressure measurement:

• Clean the earpieces and diaphragm ⓘ before and after every use with antiseptic or approved disinfectant wipes.
• Warm the diaphragm in your hand before placing it against the client.
• Put the earpiece tips into your ears with the bends pointing forward.
• Make sure the earpieces fit snugly without causing pain or discomfort.
• Place the diaphragm over the brachial artery and hold it in place.
• Keep the environment quiet.
• Do not let anything touch the tubing while listening.
• Ask the client to stay silent during the measurement.
• If the tubing touches something, clean it thoroughly before storing the stethoscope.

If you routinely use a stethoscope, keep your own device for your personal use.

The Support Worker’s Role

A support worker’s role in blood pressure measurement varies by employer and province.

In some provinces, territories, agencies, and facilities, measuring blood pressure is a delegated act.

If the care plan includes blood pressure measurement, make sure:

• Your employer allows you to perform the procedure.
• The procedure appears in your job description.
• You received special training.
• You reviewed the procedure with a nurse.
• A nurse is available to answer questions and supervise you.

Blood pressure changes affect the client’s care plan, so accurate measurement is important.

General Guidelines for Measuring Blood Pressure

Follow these rules before and during blood pressure measurement.

Throughout blood pressure measurement, promote the client’s dignity, independence, individualized care, preferences, privacy, and safety.

1. Do not use an arm with an IV infusion.
2. Do not use an arm with a cast.
3. Do not use an arm with a dialysis access site.
4. If the client had breast surgery, do not use the arm on that side.
5. Avoid an injured arm.
6. Let the client rest for 10 to 20 minutes before taking the measurement.
7. Have the client sit or lie down unless the physician ordered a standing measurement.
8. Choose the correct cuff size.
9. Apply the cuff to the bare upper arm.
10. Remove clothing that interferes with measurement.
11. Make sure the cuff fits snugly.
12. For manual measurement, place the entire stethoscope diaphragm firmly against the skin over the brachial artery.
13. Keep the room quiet. Talking, television, radio, and hallway noise interfere with an accurate measurement.
14. Keep the manometer clearly visible at eye level.
15. Measure both systolic and diastolic pressures.
16. The first blood pressure sound represents the systolic pressure.
17. The point where the sound disappears represents the diastolic pressure.
18. If you are unsure of the reading, wait 30 to 60 seconds before measuring again.
19. Notify your supervisor at once if you cannot hear the blood pressure.
20. Know the client’s normal range.
21. Immediately report any reading above or below the client’s normal range.

Measuring Blood Pressure With a Stethoscope and Sphygmomanometer

Follow the procedure in order.

Pre-Procedure

1. Identify the client according to employer policy.
2. Explain the procedure to the client.
3. Perform hand hygiene.
4. Gather the sphygmomanometer with the correct-sized cuff, stethoscope, and antiseptic wipes.
5. Provide privacy.
6. Perform hand hygiene.

Gathering the equipment first keeps you from leaving the client to retrieve forgotten supplies.

Procedure

7. Clean the stethoscope earpieces and diaphragm with antiseptic wipes.
8. Have the client sit or lie down. Keep the client’s legs uncrossed. Make sure the room is quiet and relaxing. Ask the client not to speak during the measurement.
9. Choose the client’s nondominant arm ⓘ unless that arm is injured or has an IV. Keep the arm level with the heart and the palm facing up.
10. Stand no more than 1 m (3 ft) from the manometer. Keep a mercury manometer vertical, on a flat surface, and at eye level. Keep an aneroid manometer directly in front of you.
11. Expose the client’s upper arm.
12. Squeeze remaining air from the cuff. Close the valve on the bulb.
13. Find the brachial artery at the inner part of the elbow.
14. Place the cuff arrow over the brachial artery. Wrap the cuff evenly and snugly around the upper arm, at least 2.5 cm (1 in.) above the elbow.
15. Follow employer policy for the measurement:
    1. Place the stethoscope earpieces in your ears.
    2. Find the radial or brachial pulse.
    3. Inflate the cuff until you no longer feel the pulse.
    4. Inflate the cuff another 30 mm Hg beyond the point where you last felt the pulse.
    5. Deflate the cuff slowly. Note the point where you feel the pulse.
    6. Listen for the first sound. The first sound gives the systolic reading and should be near the point where the radial pulse disappeared.
    7. If the reading differs from the client’s previous readings, report the finding immediately to your supervisor.
    8. Continue deflating the cuff. Note where the sound disappears. This gives the diastolic reading.
16. Deflate the cuff completely. Remove the cuff and stethoscope.
17. Record the client’s name and blood pressure on your notepad or assignment sheet.
18. Return the cuff to its case or wall holder.

Post-Procedure

19. Provide for the client’s safety and comfort.
20. Place the call bell within reach when this step applies.
21. Remove privacy measures if used.
22. Clean the stethoscope earpieces and diaphragm with the wipes.
23. Return the remaining equipment to its proper place.
24. Perform hand hygiene.

Steps involving a call bell may not apply in community settings.

Measuring Blood Pressure With an Electronic Machine

The electronic procedure follows a similar setup, but no stethoscope is needed.

Pre-Procedure

1. Identify the client according to employer policy.
2. Explain the procedure.
3. Perform hand hygiene.
4. Gather the blood pressure machine and antiseptic wipes required by agency policy.
5. Provide privacy.

Procedure

6. Clean the cuff surface that touches the client’s skin if you are unsure whether it was cleaned earlier.
7. Perform hand hygiene.
8. Have the client sit or lie down. Keep the room quiet and relaxing. Ask the client not to speak during the measurement.
9. Choose the nondominant arm unless it is injured or has an IV. Position the arm at heart level with the palm facing up.
10. Stay close to the client, no more than 1 m (3 ft) from the blood pressure machine, so you have a clear view of the display.
11. Expose the upper arm. Clothing under the cuff affects accuracy.
12. Find the brachial artery at the inner aspect of the elbow.
13. Place the cuff arrow over the brachial artery. Wrap the cuff evenly and snugly around the upper arm at least 2.5 cm (1 in.) above the elbow.
14. Ask the client to relax the arm. Press the machine’s On button.
15. Wait for the full cycle to finish. Read the blood pressure from the screen. Observe the client throughout the procedure for safety and comfort.
16. Remove the cuff.
17. Offer to gently massage the client’s arm. The inflated cuff temporarily interferes with blood returning to the heart, so the arm may briefly feel tingly or sore.
18. Record the client’s name and blood pressure on your notepad or assignment sheet. Immediately report a reading that differs from the client’s previous readings. Electronic machines are not always correct, so pay attention to the client. If you are in doubt, have registered staff check the machine.

Post-Procedure

19. Provide for safety and comfort.
20. Place the call bell within reach when this step applies.
21. Remove privacy measures if used.
22. Clean all equipment that touched the client. Return the cuff to its case or wall holder.
23. Return the remaining equipment to its proper place.
24. Perform hand hygiene.

Steps involving a call bell may not apply in community settings.

What to Report and Record

For a manual blood pressure measurement, report and record according to employer policy:

• The blood pressure
• Which arm you used, right or left
• The time of day
• Your observations and basic assessments

For an electronic blood pressure measurement, report and record according to employer policy:

• The blood pressure
• The time of day
• Your observations and basic assessments

Other team members need to know the time of the measurement. Blood pressure should be taken at the same time each day unless the supervisor requests a change.

Team members compare their readings with earlier readings.

Actions, observations, and basic assessments are reported and recorded for legal reasons and to keep the health care team informed.