4.4: Blood Pressure

Blood pressure (BP)

The force that blood exerts against the walls of arteries

Systolic BP

Maximum BP during the contraction of the heart

Diastolic BP

The pressure level in the arteries during the relaxation of the heart (occurs between beats)

Unit of measurement for BP

mmHg (millimeter of mercury)

Normal systolic BP range for adults

90-120 mmHg

Normal diastolic BP range for adults

60-80 mmHg

Normal BP for adults

Elevated BP

Hypertension

Hypotension

Premature BP

0-3 months old BP

3-6 months old BP

6-12 months old BP

1-3 years old BP

3-6 years old BP

6-12 years old BP

12 years old and above BP

Auscultation method

Listen for sounds in the brachial artery using a sphygmomanometer and a stethoscope

Electronic sphygmomanometer

Step 1 of measuring BP

Gather a stethoscope, a sphygmomanometer, and the patient’s medical record

Step 2 of measuring BP

Identify the patient by confirming their name and date of birth

Step 3 of measuring BP

Expose the entire arm

Step 4 of measuring BP

Lay the patient’s bare arm on a flat surface, making sure that the upper arm is on the same level as their heart

Step 5 of measuring BP

Select the appropriately sized cuff

Step 6 of measuring BP

Located the brachial artery in the antecubital space

Antecubital space

The area inside the elbow crease that must be palpated deeply to palpate the brachial artery

Step 7 of measuring BP

Step 8 of measuring BP

Ensure that the gauge is clearly visible and that the tubing is unobstructed

Step 9 of measuring BP

Step 10 of measuring BP

Find the radial pulse with one hand and pump the bulb with your other hand

Step 11 of measuring BP

Wait 30 seconds once you have deflated the cuff to give time to the brachial artery to refill

Step 12 of measuring BP

Insert the stethoscope earpieces, making sure the sound is loud and clear

Step 13 of measuring BP

Step 14 of measuring BP

Step 15 of measuring BP

Obtain the systolic pressure by taking note of the first time you hear a repetitive sound on the dial as the pressure falls

Step 16 of measuring BP

Continue to deflate the cuff

Step 17 of measuring BP

Obtain the diastolic pressure by listening for the last static sound

Step 18 of measuring BP

Continue to deflate the cuff another 10 mmHg

Auscultatory gap

An interval of absent Korotkoff sounds, which usually occurs in patients who are hypertensive

Step 19 of measuring BP

Rapidly deflate the cuff, remove it, and sanitize it

Step 20 of measuring BP

Record the BP in the patient’s medical chart

Korotkoff sounds

Sounds heard during BP measurement made up of 5 phases

Phase I of Korotkoff sounds

The systolic pressure; take note where the first sound appears on the dial

Phase II of Korotkoff sounds

Softer swishing sound caused by increased arterial blood flow

Phase III of Korotkoff sounds

The sounds become louder and crisper, then a rhythmic tapping is heard

Phase IV of Korotkoff sounds

The sounds become muffled and softer as the blood starts to flow fairly easier

Phase V of Korotkoff sounds

Diastolic pressure; where on the dial that the sounds disappear completely

For hypertensive patients with an auscultatory gap

Monitor the pulse through palpation to determine the systolic BP before, then record the BP manually or electronically