Circulation Lab: Blood Pressure Measurement and Analysis

1. Labs 33 Circulation

2. Lab Pressures in the Systemic Circuit • Systolic pressure: • peak arterial pressure during ventricular systole • Diastolic pressure: • minimum arterial pressure during diastole • Pulse pressure: • difference between systolic pressure and diastolic pressure • Mean arterial pressure(MAP): • MAP = diastolic pressure + 1/3 pulse pressure

3. Measuring blood pressure • Enclose arm in cuff • Inflate to 160+ mmHg • Slowly allow pressure out while watching needle and listening to brachial artery with stethoscope • Watch and listen for the point where blood starts to flow through the cuff to the arm – this is the max pressure or systolic • Continue slowly letting pressure out until the point where you no longer hear the sound of turbulent blood flow (and needle stops bouncing) this is the point at which blood can flow freely meaning the pressure in cuff is just below minimum pressure or diastolic

4. MAP • MAP is considered to be the perfusion pressure seen by organs in the body • MAP of 60 is necessary to perfuse the tissues • Formula is an estimate • Diastole counts for 2/3 of MAP because 2/3 of cardiac cycle is spent in diastole (and 1/3 in systole) • At high HR, this difference decreases and a better estimate is actually just the average of systole and diastolic

5. Lab #37 • Follow instructions on lab handout and enter your data there • Part 1 – auscultation • Part 2 – blood pressure: • At rest • Lying down • After exercise • Part 3 – measure pulse at three different locations

6. When done • We’ll put up the values on the board and look at the variation

7. Assignment • Work in groups of 2 (3 max) • Lab guide filled out with data for yourself • Review Sheet Lab 33A- numbers 1 - 6, 11 - 28