# Protocol for the measurement of blood pressure by screener

PROTOCOL FOR THE MEASUREMENT OF BLOOD PRESSURE
USING THE MICROLIFE™ AUTOMATED BLOOD PRESSURE DEVICE (MODEL #3AA1-2)
MATERIALS:
1. Microlife automated blood pressure device
2. Regular adult blood pressure cuff
3. Large adult blood pressure cuff
4. Calculator
5. Plasticized tape measure
6. 4 spare batteries (size AA; 1.5V)
7. Data collection form; pen with black ink; clip board.
8. Study table and chair
BLOOD PRESSURE MEASUREMENT PROCEDURES
Blood pressure measurement: The blood pressure measurement and the design and
operation of the automated blood pressure device are based upon the combined
principles of compression of the brachial artery under an elastic, inflatable cuff and the
digital registration of systolic and diastolic blood pressures and the pulse using an
oscillometric method. The blood pressure cuff is inflated automatically.
Arm circumference measurement: Since individuals have different arm sizes, several
different sized cuffs are available. Proper cuff size must be used to avoid incorrect
estimate of the blood pressure. Arm circumferences should be measured in the
patient’s left arm prior to being seated for the blood pressure measurement. Use the
following procedures to measure the participant’s arm circumference to determine the
appropriate cuff size.
ARM CIRCUMFERENCE MEASUREMENT PROTOCOL
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Ask the patient to remove clothing that is covering the upper left arm
Request that the patient sit with the forearm horizontal to the floor (the elbow
should be bent)
Measure the arm length from the bony prominence of the shoulder girdle
(acromion) to the tip of the elbow using a tape measure
Determine the midpoint of the upper arm and mark this on the back of the arm
Ask the patient to relax his/her arm along the side of the body
Draw the tape measure horizontally around the arm at the midpoint mark, but do
not indent the skin. Record the measurement in centimeters.
Use the measurement to determine the correct cuff size.
Arm circumference
Cuff size
22.0-31.9 cm
regular cuff
32.0-42.0 cm
large cuff
If the arm measures less than 22.0 cm or greater than 42.0 cm, the patient is not eligible
for the study. In this case, thank the patient for coming and provide a gift card.
For patients whose arm circumferences meet the measurement specifications, seat
them comfortably at the table with the left arm resting on the table.
APPLICATION OF THE CUFF
Use the following procedure when applying the cuff.
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Ensure that the participant is seated comfortably and both feet are flat on the
floor. The sleeve on the left arm should be rolled up or the garments removed.
Slip the left arm into the appropriately sized cuff and position the cuff on the
upper arm 2 cm to 3 cm above the elbow. The tube should point in the direction
of the lower arm.
Tighten the free end of the cuff and close the cuff by affixing the Velcro. The
cuff should be snug on the upper arm so that 2 fingers will fit between the cuff
and the upper arm.
MEASUREMENT PROCEDURE
After the cuff has been appropriately positioned:
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Allow the patient to rest quietly for 5 minutes without talking before taking the
measurement
Set the instrument to measure a single (1) blood pressure
Press the “START” button to inflate the cuff. The cuff will inflate and deflate
automatically.
Record the digital readings for systolic and diastolic blood pressures on the
appropriate places on the form.
Wait at least 30 seconds between blood pressure readings. Take and record 3
blood pressures.
DETERMINATION OF PATIENT ELIGIBILIITY BASED ON BLOOD PRESSURE
Blood pressure eligibility criteria are based on the average of the second and third
systolic and the average of the second and third diastolic blood pressure
measurements. To calculate the averages, enter the second plus the third systolic
blood pressure into the calculator and then divide the sum by 2. Record the average
systolic blood pressure on the data collection form. Enter the second plus third diastolic
blood pressures and divide the sum by 2. Record the average diastolic blood pressure
on the data collection form. See data collection form for eligibility criteria.