1. Arterial Blood Pressure

2. Definition. Factor affecting blood pressure. Causes. Classification
Definition. Factor affecting blood pressure . Causes . Classification . Type of blood pressure apparatuses . How to measure . Treatment .

3. Arterial Blood Pressure (BP)
Is a measure of the force that the circulating blood exerts against the arterial wall OR
The pressure force generated by the pumping action of the heart on the wall of aorta & arterial blood vessels per unit area.
It tells us how hard the heart is working.
Too high means the heart is working extra hard and this could be very dangerous!

4. Blood pressure almost always is measured in millimeters of mercury (mmHg). Occasionally pressure is measured in centimeters of water ( cm H2O) 1 mmHg = 1.36 cm H2O

5. Factors affecting BP
Sex M > F …due to hormones/ equal at menopause.
Age Elderly > children …due to atherosclerosis.
Emotions  due to secretion of adrenaline & noradrenaline.
Exercise  due to  venous return.
Hormones … (e.g. Adrenaline, noradrenaline, thyroid H).
Gravity  Lower limbs > upper limbs.
Race Orientals > Westerns … ? dietry factors, or weather.
Sleep  due to  venous return.

6. Factors determining BP
Blood Pressure = Cardiac Output X Peripheral Resistance
(BP)
(CO)
Flow
(PR)
Diameter of arterioles
BP depends on:
1. Cardiac output.
2. Peripheral resistance.
3. Blood volume.

7. Cardiac Output Is the volume of blood being pumped by the heart, in particular by a Left or Right ventricle in the Time interval of one minute Cardiac Output (Q) = SV × HR Peripheral Resistance The sum of resistance to flow that must be overcome to push blood through the circulatory system Stroke Volume Is the volume of blood pumped from one ventricle of the heart with each beat

8. Causes Of Hypertension
Essential hypertension 95%
Secondary hypertension 5%
Renal
Endocrine
Pregnancy
Drugs
Coartation of aorta
Others

9. Diastolic Blood Pressure
Systolic Blood Pressure
Is the measured pressure placed on the blood vessels while the heart is contracting.
Diastolic Blood Pressure
Is the measured pressure placed on the blood vessels while the heart is at rest. (not contracting)

10. NOTE !!! Pulse pressure Systolic BP – Diastolic BP
The most important determinant of pulse pressure is STROKE VOLUME.
Mean arterial pressure Diastolic BP + 1/3 Pulse pressure
Is a term used in medicine to describe an average blood pressure in an individual

11. Classification of blood pressure for adults
Hypertension
Sustained raised in BP which require medical interventions.
Classification of blood pressure for adults
Category
Systolic mmHg
Diastolic mmHg
Hypotension
< 90
< 60
Normal
90 – 120
60 – 80
Prehypertension
121 – 139
81 – 89
Stage 1 Hypertension
140 – 159
90 – 99
Stage 2 Hypertension
≥ 160
≥ 100

12. How is Blood Pressure Taken?
Invasive
Non-Invasive
Blood Pressure
Palpatory Method
Auscultatory Method
Ultrasonic Method
Oscillometric Method
Tonometry
Extravascular Sensor
Intravascular Sensor 1 2

13. Types Of BP Apparatuses
Mercury Type
Aneroid Type
Digital Type

14. A- Palpatory Method Feel the radial pulse.
An occlusive cuff is placed on arm and inflated above the level at which the pulse become impalpable.
Gradually deflate it.
The level at which the pulse become palpable again is taken as systolic pressure.

15. 2- Technique does not require much equipment
1- The blood pressure can be measured in noisy environment too
ADVANTAGES
2- Technique does not require much equipment
1- Only the systolic pressure can be measured (not DP)
DISADVANTAGES
2- The technique does not give accurate results for infants and hypotensive patients

16. B- Auscultatory Method
Apply the cuff one inch above the elbow
Palpate the brachial artery
Place the stethoscope lightly over it
Inflate the cuff above the systolic level determined by the palpatory method
Lower the pressure in the cuff
The level at which Korotkoff sound are heard is the Systolic pressure.
The level at which sound disappear is diastolic pressure.

17. ADVANTAGES DISADVANTAGES
1- Auscultatory technique is simple and does not require much equipment
DISADVANTAGES
1- Auscultatory tecnique cannot be used in noisy environment
2- The observations differ from observer to another
3- A mechanical error might be introduced into the system e.g. mercury leakage, air leakage, obstruction in the cuff etc.
4- The technique does not give accurate results for infants and hypotensive patients

18. Korotkoff sound
The first Korotkoff sound is Clear tapping, repetitive sounds for at least two consecutive beats is considered the systolic pressure.
The second sounds are the murmurs heard for most of the area between the systolic and diastolic pressures.
The third = A loud, crisp tapping sound.
The fourth sound, at pressures within 10 mmHg above the diastolic blood pressure, were described as “muffling" and "muting".
The fifth Korotkoff sound is silence as the cuff pressure drops below the diastolic blood pressure. The disappearance of sound is considered diastolic blood pressure .

19. Common problem in BP measurement
Wrong cuff size
Excess pressure of stethoscope
Patient arm at the wrong level
White coat effect
Auscultatory Gap (silent gap)

20. Auscultatory Gap
In some hypertensive patients the Krotokoff sound disappear for some time between systolic and diastolic pressure.
So there is a risk of either recording a low systolic or high diastolic .
Avoid it by using palpatory method before the Auscultatory method.

21. Treatment Lifestyle changes include : Stop smoking Low fat diet
Treatment goal <140/85 mmHg
(130/80 mmHg in diabetic)
Lifestyle changes include :
Stop smoking
Low fat diet
Low salt intake
Exercise
Reduce wt
Drugs:
ACE inhibitor
B-blocker
Ca channel blocker
Diurtics

22. Postural Hypotension
Drop in systolic BP>20 mmHg OR diastolic BP>10 mmHg after standing for 3 minutes.
Causes:
Hypovolemia
Antipsychotics
Addison‘s disease
hypopituitarism

23. Apply Your Knowledge
Normal Blood Pressure in Adults (18 or older) is ??
What can cause sounds to be heard down to zero mmHg??
A cuff with a bladder too small for the patients arm will result in ??
If the cuff is applied too loosely, the pressure reading will be ??
How you can avoid incorrectly assessing the systolic blood pressure due to the auscultatory gap??

24. Thank you