CNA Skills – Blood Pressure Taking

CNA Skills – Blood Pressure Taking the pressure exerted by blood against the walls of the blood vessels usually referring to the pressure within the arteries

1. To determine the condition of the patient as revealed by diastolic and systolic pressure
2. To aid in medical diagnosis

Special Considerations:
1. Keep the patient physically or emotionally quiet because excitement or exercises raises blood pressure
2. Use either arm in taking blood pressure, although recorded BP recording differ at times
3. Too hard pressure on the brachial artery with the belt of the stethoscope prevents sounds from coming through


Key Points

1. Ask the patient to lie down or sit with one arm well supported
2. Roll sleeves of patient’s gown well above the elbow The cuff is placed and applied so that the brachial artery may be compressed with pressure. Place the mercury manometer in such a position that the meniscus of the mercury can be read at eye level
3. Apply cuff smoothly and snugly above the elbow and tuck the last few inches of the band into final fold of the wrapping
4. Use the fingertips to feel for a strong pulsation in the ante-cubial space
5. Place the stethoscope on the brachial artery on the ante-cubial fossa where the pulse was noted
6. Close the valve on the air Sufficient pressure in the cuff
7. Close the valve on the air bulb and pump the bulb of the manometer until the mercury rises to approximately 20 mm. Above the point where it is anticipated that systolic pressure will be obtained Sufficient pressure around the upper arm prevents blood from flowing through the brachial artery
8. Release air gradually and note on the manometer the point at which the first sound is heard and record this figure as the systolic pressure Systolic pressure is that point at which the blood in the brachial artery is first able to force its pressure exerted in the vessel by the cuff of the manometer
9. Continue to release the air gradually from the cuff and note the reading on the manometer at which the towel thumping sound is last heard and record this figure as the diastolic pressure Diastolic pressure is that point at which blood flows freely in the brachial artery and is equivalent to the amount of pressure normally exerted on the walls of the arteries when the heart is at rest
Allow the remaining air to escape, remove the cuff and make the patient comfortable

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