Blood Pressure And BMI

Blood Pressure

WIPERS

Check Name and DOB

3 Questions BEFORE taking BP

1. Caffeine – in last hour2. Exercise – In last hour

3. Cigarette – in last 30 mins

How To Measure Blood Pressure (as given by Oxford Clinical Guide)

• Ask arm preferences• Make sure no tight clothing• Palpate for Brachial Artery• Use CORRECT cuff size - Centre bladder over brachial

artery + apply snugly• Support arm in horizontal position at mid-sternal

level.• Inflate the cuff while palpating the brachial artery,

until the pulse disappears• Note the pressure at which it disappears and deflate

the cuff.

• Re-inflate the cuff until 20-30mmHg above the previous pressure

• Place stethoscope over the brachial artery (Shouldn’t hear any sounds at this point)

• Deflate slowly at 2mmHg per second• Start of sustained repetitive tapping sounds =

systolic pressure.• Whoosh at end or sound disappears =

diastolic pressure

Video

• This video is useful, they skip the step of inflating with palpating the pulse but as a rough guide it can help.

• http://www.youtube.com/watch?v=S648xZDK7b0

Korotkoff Sounds

• These are the arterial sounds you hear when taking blood pressure. They are caused by turbulence in the blood flow caused by compression of the artery.

Blood Pressure and Hypertension

Body Mass Index

= A measure for human body shape based on height and weight

• Formula: KNOW THIS

How to perform:• Explain • Ask patient to remove shoes• Weigh on scales (Kg) – Bend over scales and Get

head close to scales to show you are getting an accurate reading

• Measure height (m) – use wall tapes. – Get patient to stand with heels to wall and back of head against wall– Keep Tape straight– Tell pt to stand up right– Get accurate reading

• If you are getting a reading that comes miles off what you expect then don’t panic. Make sure you used metres rather than cm and that you read kg off the scales.

Possible Questions

• What other possible measures of size/obesity etc. are there?– Waist/hip ratio. Fat callipers.

• What is considered the normal range for BMI?– 18.5-24.9. We’ve had different answers given to us

for this so it may be worth saying some sources also say 20-24.9 but the first is the one in the Oxford Clinical Medicine handbook.

• What are the sounds you are listening for in blood pressure tests?– Korotkoff sounds. The first sound is systolic.

Korotkoff 4/5 is diastolic. That is the move between the last noises and silence.

• How do you choose the size for a sphygmomanometer?– Two thirds of the cuff should be the circumference

of the arm.• What blood pressure is regarded as

hypertension?– Above 140/90mmHg

• Above what BMI is an individual considered obese?– Greater than 30.0 – Obesity I; Greater than 35.0 –

Obesity II; Greater than 40.0 – Morbidly obese.• What do systolic and diastolic blood pressure

mean?– Systolic (maximum pressure in artery following

ventricular systole), Diastolic (lowest pressure in the artery during ventricular diastole)

• Why is getting the correct cuff size on a sphygmomanometer important?– If its too big, the bp will be artificially low, if its too

small it will be artificially high• Why is BMI not a perfect measure to use?– It doesn’t take into account an individuals build

and can be different in different ethnicities.• What causes Korotkoff sounds?– Turbulence in blood flow in artery caused by cuff

compressing artery.

• What are some possible complications of hypertension?– Ischaemic Heart Disease, Stroke, Heart failure,

Kidney failure• What are some possible factors that could

influence blood pressure?– Age, circadian variation, food, drink, posture, pain

and anxiety (“white coat” hypertension)