Learn how to take a manual blood pressure! As a nurse it is essential you know how to take a manual blood pressure. The manual blood pressure reading is obtained with an aneroid sphygmomanometer, blood pressure cuff, and stethoscope.
Once obtained, the nurse records it with the systolic reading (this is the first sound heard) over the diastolic blood pressure reading (the point when the sound stops). For example, a blood pressure reading may look something like this: 114/76. The 114 is the systolic reading and the 76 is the diastolic reading.
Why does a nurse need to know how to check a manual blood pressure when there are digital devices that will perform this skill?
Manual blood pressure measurement devices provide a more accurate blood pressure reading than digital ones. According to a study by Journal of Clinical and Diagnostic Research, an aneroid device (which is used during a manual blood pressure measurement) is more accurate than a digital device (Shahbabu, 2016). Therefore, as a nurse you should always reassess a suspicious blood pressure reading with a manual blood pressure measurement.
Video on How to Take a Blood Pressure Manually
Steps on How to Take a Blood Pressure Manually
1. Perform hand hygiene and gather supplies
- Supplies needed: stethoscope and blood pressure cuff with a sphygmomanometer
- Tip: always use the right size cuff
2. Have the patient sitting or lying down with the arm at heart level. Turn the arm outward with the palm up. Be sure the legs are uncrossed.
- Find the brachial artery:
- This is the most common site for checking the blood pressure and is a major artery in the upper arm that divides into the radial and ulnar artery.
- To find this artery, extend the arm and have the palm facing upward. The pulse point is found near the top of the cubital fossa, which is a triangular area that is in front of the elbow.
3. Place and secure the blood pressure cuff on the patient’s upper arm. Place it about 2 inches above the elbow. In addition, make sure the arrow on the blood pressure cuff is lined up with the brachial artery. Don’t place the blood pressure cuff over clothes or the gown.
4. First, we will estimate the systolic pressure by palpating the brachial artery and inflating the cuff to the point where the pulse disappears. Note that number on the gauge when you no longer feel the brachial artery. Then deflate the cuff and wait 30 to 60 seconds.
- Why do we do this? By first estimating the systolic pressure, we can avoid missing the auscultatory gap, if it is present. The auscultatory gap is an abnormal silence during auscultation that can lead the clinician to obtain an inaccurate systolic reading, which is the first sound heard during auscultation. This gap occurs in SOME patients (not all), especially if they have hypertension.
5. Place your stethoscope in your ears, palpate the brachial artery again, and place the bell of the stethoscope lightly on the brachial pulse site (you can use the diaphragm rather than the bell if you want, but the bell is the best for hearing low pitched sounds).
6. Inflate the cuff 30 mmHg above the number you felt the brachial artery disappear when estimating the systolic pressure. For example, if the brachial artery disappeared at 100 mmHg, inflate the cuff to 130 mmHg.
7. Deflate the cuff slowly with the valve (about 2 mmHg per second).
8. Listen for the very first sound and note the point on the gauge when you heard it…this is the systolic number.
9. Continue to allow the air to leave the cuff and note the point on the gauge when the sound stops completely (this is the diastolic pressure number reading).
10. Open the valve completely and let the air leave.
11. Remove the cuff.
12. Clean cuff and device if multi-use device and perform hand hygiene.
13. Document the reading and which arm you measured the blood pressure in.
How to Interpret the Blood Pressure Reading
American College of Cardiology 2017 Updated Guidelines for High Blood Pressure:
- Normal BP- SBP: <120 DBP: <80 mm Hg
- Elevated BP- SBP: 120-129 DBP: <80 mm Hg
- Hypertension Stage 1- SBP: 130-139 or DBP: 80-89 mm Hg
- Hypertension Stage 2- SBP: ≥140 or DBP: ≥90 mm Hg
For a patient to be diagnosed as having hypertension, they need an average reading based on 2 readings or more that are obtained on 2 or more occasions.