Lab 11: Blood Pressure

What is blood pressure?

amount of force/pressure exerted against the walls of an artery and recorded as two numbers, the systolic pressure and the diastolic pressure

What is the unit of blood pressure

millimeters (mm) of Mercury (Hg)

What is systolic pressure

LV contraction, health of ventricles

What is diastolic pressure

relaxation, health of the large arteries

Where is the brachial artery

pink side upper arm above the elbow

Auscultatory Method

listening to the heart sounds in the brachial artery using a stethoscope and sphygmomanometer

gold standard

What are the two types of sphygomomanometers?

aneroid and mercury filled

Phase 1 Korotkoff sounds

appearance of a faint tapping sounds “systolic pressre”

Phase 2 korotkoff sounds

sound becomes louder usually characterized by a swishing sound

Phase 3 Korotkoff sounds

sound is very distinct and loud

Phase 4 Korotkoff sounds

sound becomes muffled and softer “diastolic pressure”

Phase 5 Korotkoff sounds

sound disappears

Difference between Korotkoff sounds at rest and exercising

at rest the time between phase 4 and 5 is very short so diastolic is when the sounds stops, when exercising the time between is longer so diastolic is taken at phase 4

BP measurement steps at rest

1) ask for permission, legs not crossed, rest arm below or at heart level

2) find brachial pulse

3) choose the right cuff size and put on tight

4) test stethoscope

5) close bulb and inflate to 160

6) slowly deflate

7) When needle starts pulsing phase 1 is soon

8) Note systolic and diastolic

How does cuff size impact BP accuracy

if cuff is too big results in low BP measurement because it takes longer to hear systolic

if too tight patient’s systolic overestimated becuase blood vessel is occluded quickly so phase I is earlier

too wide will underestimate BP

too narrow will overestimate BP

What factors affect the accuracy of the auscultatory method?

cuff size and cuff tension

Hypertension

silent killer

high blood pressure

major risk factor associated with heart disease

Normal BP defined by AHA

systolic less than 120 and diastolic less than 80

Elevated BP by AHA

systolic 120-129 and diastolic less than 80

high blood pressure (hypertension) stage 1

systolic 130-139 or diastolic 80-89

high blood pressure stage 2

systolic 140 or higher or diastolic 90 or higher

hypertensive crisis

systolic higher than 180 and/or diastolic higher than 120q

treatment for high BP

healthy diet and exercise, diuretics, ACE inhibitors, beta blockers, vasodilators

reason BP is taken at rest and during exercise

BP taken at rest can help to identify a risk factor for heart disease whereas BP taken during exercise can help in the diagnosis of heart disease

normal BP responses to exercise

systolic pressure elevates with each increase in workload due to stretch in the left ventricular wall and increased force to pump blood

diastolic pressure either remains the same or may increase due to vasodilation of the arteries from the exercise

Abnormal BP responses to exercise

systolic pressure doesn’t elevate or declines because heart disease affects the heart’s ability to contract

diastolic pressure elevates after due to high pressure in the blood vessels while the heart is in diastole