How to Measure ABP

Dr. Nisreen MansourDepartment of Physiology

Dr. Nisreen Mansour

Blood Flow;Laminar Flow Vs. Turbulent Flow

• Normal laminar flow produces no sounds

Dr. Nisreen Mansour

Arterial Blood Pressure

• ABP; Is the lateral force exerted by the column of blood on the lateral walls of arteries

• ABP is expresses as systolic over diastolic• Systolic BP; is the maximum pressure caused by

the ejected blood during peak of ventricular systole; normally 90-140 mm Hg

• Diastolic BP; is the lowest pressure at the end of ventricular diastole; normally 60-90 mm Hg

Dr. Nisreen Mansour

Systolic BP

Dr. Nisreen Mansour

Diastolic BP

Dr. Nisreen Mansour

• Mean Arterial Blood Pressure (MAP)

is the average perfusing pressure during cardiac cycle

MAP = diastolic +1/3 pulse pressure

= 93 mm Hg

Dr. Nisreen Mansour

Arterial Pressure Wave

• Diacrotic notch is caused by sudden closure of aortic valve causing sudden drop of aortic pressure

Diacrotic notch

Dr. Nisreen Mansour

Arterial Blood Pressure

• Average ABP = 120/80 mm Hg• However, there are physiological variation:• Age• Sex• Race• Meals• Posture• Emotion• Exercise• Sleep

Dr. Nisreen Mansour

How To Measure ABP

• Indirect

• Usually in Brachial artery

• Using Syphygmomanometer

• 2 methods;Palpation methodAuscultation Method

Dr. Nisreen Mansour

How To Measure ABP; Palpation Method

• Gives a rough idea about value of systolic BP; HOW?

Apply the cuff to upper arm Your middle 3 fingers of one hand feeling radial

pulse Using the other hand, inflate the cuff till pulse

disappears Slowly deflate the with your eyes at the

manometer; the value at which u feel the pulse again is the Systolic BP

Dr. Nisreen Mansour

How To Measure ABP; Auscultatory Method

• With the cuff still around the upper arm (NOTICE THAT CUBITAL FOSSA MUST BE CLEAR)

• Place the stethoscope on anatomical site of brachial artery (medial side of antecubital fossa, u can feel its pulse)

• Raise the pressure in the manometer by about 10-20 mm Hg above the value that u measured by palpation method before

• Start to deflate very slowly (by 2mm Hg) until u hear sound; Korotkov’s sounds

Dr. Nisreen Mansour

How To Measure ABP; Auscultatory Method

• The 1st appearance of sounds indicates systolic BP

• The intensity of sound increases (blowing) as the pressure in cuff is decreased (Turbulent flow)

• Sound is muffled gradually then disappears indicating Diastolic BP

Dr. Nisreen Mansour

How To Measure ABP; Auscultatory Method

Dr. Nisreen Mansour

How To Measure ABP; Auscultatory Method

Dr. Nisreen Mansour

Arterial Pulse

• Where u can feel arterial pulsation?

• Arterial pulse is the expansion of arterial wall by the ejected blood during systole causing sudden increase in aortic pressure that is transmitted as pressure wave to systemic arteries

Dr. Nisreen Mansour

Pulse

• The strength of pulse is determined by the pulse pressure

• Pulse Pressure = Systolic BP –Diastolic BP = = 120-80 = 40 mm Hg

• PP is affected by stroke volumecompliance of arteries

Dr. Nisreen Mansour

Pulse

• Significant because it gives an idea about:

• Heart rate

• Certain CV diseases:Water hammer pulsePulsus alternans

Dr. Nisreen Mansour

THANK U