1. Blood Pressure (BP) -practical
By Tereza Jandova

2. Overview What is a BP? Types of BP Factors affecting BP
How to measure BP
Auscultation method
Practice

3. Blood pressure Is the force of blood against blood vessel walls
The pumping action of the heart generates the flow
Pressure occurs when the flow is met by resistance from blood vessel walls

4. Types of BP Depending on the nature of blood vessel Arterial BP
Venous BP
Capillary BP

5. Factors affecting BP Cardiac Output (volume of blood/min) Blood volume
Product of stroke volume X heart rate
60ml X 60 = ??? ml
Blood volume
Resistance
Artery diameter
Blood viscosity (thickness)
E.g. fat in the blood increase viscosity
In ventricles about 100ml of blood *(the end of diastolic volume EDV, e.g. filling) – but not all is ejected = termed ejection fraction (ED)
End systolic volume – after ejection, usually 60% is ejected
All dependent on CONTRACTILITY, PRE-LOAD AND AFTER-LOAD

6. Blood pressure changes all the time:
It decreases when we sleep, or when we are at rest
It increases when we are active, excited, practicing sports, stressed and nervous
Changing blood pressure is a vital part of a healthy cardiovascular system
Hypertension, or high blood pressure, happens when the blood pressure stays too high over an extended period of time:
Can cause the heart to have to work too hard and the force of the blood flow can damage your arteries, heart, kidneys, brain and eyes.

7. BP is recorded as 2 numbers: Systolic pressure Diastolic pressure
– heart contracts (≈0.3 sec)
Diastolic pressure
– heart relaxes (≈0.5 sec)
BP is measured in mmHg (millimetres of mercury)
Is the extra pressure generated by a column of mercury one millimetre high =  pascals

8. Blood Pressure Graph
Pulse Pressure
Systolic
Dicrotic Notch
Diastolic
Average Pressure
By taking your pulse, you can feel that blood pressure fluctuation with each heartbeat.
The pulse which you feel is actually a pressure wave that travels from your heart through your arteries

9. Systolic pressure
Is the maximum pressure exerted by the blood against the artery walls
It results when the ventricles contract.
Normally, it measures 120 mm Hg
Dicrotic Notch
Pressure in the aorta that goes up slightly when the valve closes (the aorta constricts a little bit)
Diastolic pressure
Is the lowest pressure in the artery
It result when the ventricles are relaxed and is usually around 80 mm Hg

10. How to measure BP

11. EUREKA! In late 1890s, an Italian physician –
Scipione Riva Rocci invented the
Sphygmomanometer

12. Shygmo (from the Greek) => pulse Manometer => pressure meter
- Consisted of a mercury column
Manometer, a rubber sleeve which
is filled with air, and a squeeze bag
to inflate the rubber sleeve

13. Measurements of BP Direct (invasive) blood pressure:
It measures the BP internally by using a sensitive IV catheter inserted into an superficial artery
Indirect (Non-invasive) blood pressure:
Auscultation - the act of listening to sounds
Oscillometry - based on the change of the magnitude of oscillation (vibration)
Doppler (ultrasound determines the flow distal to the artery)

14. Invasive method looks somehow like this

15. Non-invasive AUSCULTATION measurement of BP - INSTURMENTS
Mercury sphygmomanometer
Aneroid barometer
Holter
Automatic ones
There are obviously also digital machines

16. Holter 24-hour blood pressure monitoring
3-channel Holter ECG monitoring

17. Procedure

18. The subject (patient) is relaxed in a sitting or lying position
A cuff (proper size) is placed on the upper arm and is inflated to constrict the brachial artery so that no blood flows
A stethoscope is placed under the edge of the cuff in the antecubital fossa
As the cuff pressure is slowly released, but the artery is still partially constricted, blood flow begins again
Sounds can be heard because the blood flows violently (powerfully) causing audible sounds.
When the artery is fully open, the blood flows freely and the sounds disappear

19. Anyone knows how are the sounds called?????????????
QUIZ TIME
Anyone knows how are the sounds called?????????????

20. KOROTKOFF’S SOUNDS Nikolai Korotkoff (Russian surgeon)
In 1905 discovered the sounds

21. Korotkoff’s sounds

22. At home to listen

23. The first sounds that are heard indicate systolic pressure (top number)
When the sounds stop, diastolic pressure has been reached (bottom number)
Average blood pressure is:
120 80

26. EXTRASss

27. Blood pressure has hydrostatic, hydraulic, and osmotic components
Hydrostatic pressure – in blood vessels is caused by the weight of the blood above it in the vessels (heart generates that pressure)
Hydraulic pressure caused by the pumping of the heart through the arteries (it is the transmission of force by means of compressing the blood)
Osmotic pressure is also present, depending on the relative concentrations of solutes on either side of the vessel walls