how to take blood pressure

patient positioning

• seated with legs and back supported

• legs uncrossed

• arms supported passively and facing up

*if supine, arm should be at side and slightly elevated (heart level)

**if standing, support arm at heart level

korotkoff sounds

5 phases of sounds heard

1. first clear, faint rhythmic tapping sound (systolic bp)

2. swishing sound

3. sound becomes louder and more intense

4. sound is abrupt, muffling, soft/blowing quality

5. last sound heard (diastolic)

cuff size

• length of cuff = ~80% of limb circumference

• width of cuff = ~40% of limb circumference

*too narrow = falsely reading high

**too wide = falsely reading low

bp procedure

1. arm at heart level

2. cuff around bare arm above antecubital fossa (elbow crease)

3. find brachial artery (medial to biceps tendon) or radial artery

4. find occlusion point (note pressure where pulse is no longer felt)

5. place diaphragm over brachial artery

6. inflate 20-30 above occlusion point

7. release air at 2 mmHg/sec

8. note systolic and diastolic

9. repeat on same air after a minute

*only 5mmHg difference = satisfactory

**>5mmHg difference = average

***>10mmHg take on other arm and use arm with highest reading

ausculatory gap

initial systolic blood pressure, gap of silence, then tapping again

record highest pressure of noise, that’s accurate systolic

bp precautions

avoid prolonged compression

avoid extremity with: peripherally inserted catheter, shunt, radial artery graft, lymphedema

bp documentation

1. systolic

2. diastolic

3. location bp taken

4. patient position (seated, lying, supine)