2. Case scenario
• You are an on-call doctor, and were asked to
see Ahmed, who is a 65 years old journalist
, known to be diabetic and hypertensive for
15 years admitted for a hernia operation.
• He suffered on the ward after the operation
from a very severe headache and blurring of
vision for the last 3 hours despite taking
paracetamol.
• Your first immediate response:
• Measure his blood pressure
3. Objectives
Define blood pressure and identify its equipment.
Describe the palpatory and auscultatory methods for ABP
measurement.
Perform ABP measurement for a fellow student using the
sphygmomanometer.
Identify Korotokoff sounds and describe their use ABP determination.
Enumerate the precautions considered before and during ABP
measurement.
Recognize the effect of exercise on the ABP.
4. Blood pressure
• The force exerted by the blood against any unit area of
the vessel wall.
• BP is 50mmHg: Means that the force exerted is
sufficient to push a column of mercury against
gravity up to a level of 50 mmHg high.
5. Factors affecting blood pressure
• Posture:
In erect posture: the systolic falls a little but soon returns
to normal by the compensatory mechanisms.
• Age: blood pressure increase with age.
- At birth: 50/30 mm Hg
- Adult:120/80 mm Hg
- Old age:170/90 mm Hg
• Sex:
Blood pressure is lower in females until menopause.
• Body build:
Obesity increase blood pressure.
6. • Diurnal variation:
Blood pressure is lower in the morning when we wake up. Gets
higher in the afternoon.
• Digestion:
Systolic blood pressure rises by 6-8 mmHg after meals
(1 hour).
• Exercise:
Systolic blood pressure increase while diastolic blood pressure
remains unchanged
• Temperature:
Cold causes vasoconstriction so increase blood pressure due to
increase peripheral resistance
• Stress:
Increase blood pressure
7. The effects of exercise on the systolic &
diastolic blood pressures
MILD TO MODERATE EXERCISE
• Systolic BP increases, while
Diastolic BP remains the same.
• Because of sympathetic
stimulation, the cardiac output
increases, which in turn
increases the systolic BP, but no
effect on diastolic BP.
SEVERE OR HEAVY EXERCISE
• Systolic BP increases further and
Diastolic BP decreases
• More sympathetic stimulation
will increase the Systolic BP
further and the Diastolic BP
drops because of a net decrease
in the total peripheral
resistance due to the more
vasodilatation effect on the
arterioles supplying the
exercising skeletal muscles than
the vasoconstriction effect on
the arterioles supplying the
other tissues.
8. BP changes with exercise
Conditions Blood pressure
Before exercise 120/80 mmHg
After mild exercise 140/80 mmHg
After heavy exercise 160/60 mmHg
.
9. Indications for blood pressure measurement
• Screening for hypertension.
• Following the effect of anti-hypertensive treatments in a
patient to optimize their management.
• Assessing a person’s suitability for a sport or certain
occupations.
• Estimation of cardiovascular risk.
• Determining for the risk of various medical procedures.
• Figuring out whether a patient is clinically deteriorating, or is
at risk for it.
11. Measurement of arterial blood pressure
• Core steps:
1. Introduce your self to the patient and check the
identity.
2. Explain the procedure and take consent.
3. Check your equipment.
a) Make sure the apparatus is working and set to zero.
b) Choose the correct cuff size.
(The length of the cuff should be 80% and the width at least 40%
of the circumference of the upper arm).
12. Measurement of arterial blood pressure
The following cuff sizes are recommended:
1. for arm circumferences of 22–26 cm, use a
small adult cuff (12x22 cm)
2. for arm circumferences of 27–34 cm, use an
adult cuff (16x30 cm)
3. for arm circumferences of 35–44 cm, use a large
adult cuff (16x36 cm)
4. for arm circumferences of 45–52 cm, use an adult
thigh cuff (16x42 cm).
13. Measurement of arterial blood pressure
1) Before you start, please ask the following
questions:
a) Have you ever get your blood pressure
checked? If so, what is your blood pressure
usually?
b) Are you in any medication for BP?
c) Did you do any exercise in the last half hour?
d) Did you have any stimulant such as tea, coffee or
a cigarette in the last half hour?
14. Measurement of arterial blood pressure
Precautions for measuring arterial blood pressure
• The cuff size should be appropriate for the age and
built of the subject.
• The cuff must be applied snuggly (not too tight
and not too loose) about 2.5 cm above the cubital
fossa.
• The free margin of the cuff should not be on the
course of brachial artery
15. Measurement of arterial blood pressure
• The manometer should be at the same level as the
heart to exclude the effect of gravity while measuring
the blood pressure.
• The mercury manometer should be in the vertical
position.
• Adequate amount of mercury in the bulb of the
instrument.
• The subject must be physically and mentally relaxed
and in a comfortable environment.
16. PALPATORY METHOD
(This method only gives an approximate estimate of the systolic blood pressure)
1. Ask the subject to sit comfortably on a chair with their arm resting on the
bench.
2. Apply the cuff around the arm and over the brachial artery about 2.5cm above
the antecubital crease. Make sure the arm is at heart level.
3. Inflate the cuff until the radial pulse disappears. By compressing the
brachial artery, the pulse or pressure wave is prevented from being
transmitted to the radial artery.
4. Deflate the cuff slowly (3-4 mmHg/second) and note the pressure at which the
radial pulse returns. This is roughly systolic blood pressure.
17. AUSCULTATORY METHOD
(This method measures both systolic and diastolic blood
pressures)
₋ Inflate the sphygmomanometer cuff until there is no
radial pulsation.
₋ Place the diaphragm of the stethoscope over the
brachial artery just above and on the medial side of the
elbow joint.
₋ Deflate the cuff slowly. A series of sounds are usually
heard
19. The Korotkoff sounds
• These sounds are produced by turbulent flow in the
constricted brachial artery.
• Phase 1: The appearance of a clear tapping sound. This
is the first sound that is heard and it represents the Systolic
Pressure.
• Phase 2: Blowing or swishing sounds.
• Phase 3: The sounds become sharper and crisper.
• Phase 4: An abrupt muffling of sounds.
• Phase 5: All sounds disappear. The point where the
sound disappears is the diastolic blood pressure.
20.
21.
22. Measurement of arterial blood pressure
• Don’t keep cuff inflated for too long.
• Do not forget to remove the cuff from the arm
and thank the patient.
• Recheck the BP of the patient after 2 minutes, by
repeating the procedure in the other arm.
• Record the systolic and diastolic pressure to the
nearest 2 mmHg, the cuff size, arm used, subject
posture, time & date of measurement.
• Tell the subject about his own blood pressure,
explain their situation, and respond to their
questions and concerns.
23. AHA guidelines for hypertension
BP category Systolic BP Diastolic BP
Normal <120mmHg and <80mmHg
Elevated 120-129mmHg and <80mmHg
Hypertension stage 1 130-139mmHg or 80-89mmHg
Hypertension stage 2 ≥ 140mmHg or ≥ 90mmHg
Hypertensive urgency > 180mmHg and/o
r
> 120mmHg
Hypertensive
emergency
> 180mmHg + target
organ damage
and/o
r
> 120mmHg + target
organ damage
24. The pulse pressure
It is the difference between systolic and diastolic blood
pressures.
• Systolic pressure = 120 mmHg and
• Diastolic pressure = 80 mmHg; then
• Pulse Pressure = Systolic – Diastolic pressure
• i.e. 120 – 80 = 40 mmHg.
25. The mean arterial blood pressure
- It is the average blood pressure within the arteries
during a whole cardiac cycle
- The force responsible for maintaining a continuous
forward flow of the blood in the circulation during the
whole cardiac cycle.
M.A.B.P.= diastolic blood pressure + 1/3 pulse pressure
26. Practical class summary
• Choose an adequate cuff size based on the subject’s upper arm size.
• Place the chosen cuff on the subject’s upper arm.
• Place the stethoscope over the brachial artery.
• Inflate the cuff to a pressure of 30 mmHg above the level at which the
radial pulse is no longer palpable.
• While slowly deflating the cuff, listen for Korotkoff phase I while
watching the manometer.
• Note the manometer reading when the onset of Korotkoff phase I is
heard.
This represents the patient’s systolic blood pressure.
• Continue to slowly deflate the cuff, watch the manometer and listen
until sounds are no longer heard (Korotkoff phase V).
• Note the manometer reading when the onset of Korotkoff phase V is
heard.
This represents the subject’s diastolic blood pressure.
• Document BP readings, arm used, subject’s posture and the cuff size
used in the subject’s notes.
