VITAL SIGNS
BLOOD PRESSURE
Learning Objective:
:
After completing this lesson, the students
will be able to;
BLOOD PRESSURE

The force produced by the
volume of blood pressing on the
resisting walls of the arteries

Systole – the working period of
the heart


The heart contracts and pumps
blood out into the circulation.
Diastole – the resting period of
the heart

The time when the heart is filling
with blood, which will be pumped
out during the next systole.
Blood pressure
Force exerted by blood
against arterial walls
 Work of the heart reflected in
periphery via BP

Blood Pressure

Systolic


Peak pressure exerted against arterial
walls as the ventricles contract and eject
blood
Diastolic

Minimum pressure exerted against
arterial walls between contraction when
the heart is at rest
Blood pressure



Measured in millimeters of mercury
(mm Hg)
Recorded as systolic over diastolic
Pulse pressure

Difference between systolic and diastolic
BP Regulation


The body constantly adjusts arterial pressure
to supply blood to body tissues
Influenced by three factors


Cardiac function
Peripheral vascular resistance
BP Regulation

Blood volume




Normal = 5000 ml
Volume increases=BP increases
Volume decreases= BP decreases
Viscosity= reaction same as volume
BP Regulation

Elasticity


Less elasticity creates greater resistance
to blood flow= > systolic BP
Decreased in smokers and increased
cholesterol
Additional considerations for
BP

Palpation


Errors


Used when BP is too weak to hear
Wrong size cuff, deflating too rapidly,
incorrect placement
Thigh

Measures 30-40 mm HG less than
normal
FACTORS INFLUENCING
BLOOD PRESSURE

1. Age – blood pressure rises with age.

Arteries lose their elasticity and become more
rigid (arteriosclerosis) resulting in even greater
resistance to heart’s effort to fill the arteries with
blood or arteries may fill with fat deposits
(atherosclerosis) that interferes with the amount
of blood that can be contained within the
arteries. Thus blood pressure is increased.
FACTORS INFLUENCING
BLOOD PRESSURE

2. Time of day – BP tends to be lowest
in morning than later during the day

3. Women have lower blood pressure
than men
FACTORS INFLUENCING
BLOOD PRESSURE

4. Exercise and activity – increases
during periods of activity or exercise
through regular exercise helps
maintain blood pressure within normal
FACTORS INFLUENCING BLOOD
PRESSURE

5. Emotions and pain tends to make
BP rise
FACTORS INFLUENCING BLOOD
PRESSURE

6. Other factors:



A person has lower BP when lying down
than when sitting or standing
BP rises when urinary bladder is full and
when legs are crossed
BP rises when a person uses tobacco,
drinks caffeinated beverage or is cold
Variations in BP

Values

The Joint National Committee BP ClassificationAdult older than 18 years.




Normal: less than120/80 mm Hg
Hypotension: less than100mm HG
Pre hypertension: more 120/80 mm Hg
Hypertension: 140/90= Stage 1;
160/100= Stage 2

Values

For the Department of health and Philippine heart
Association
- Normal BP will fall under 120/80mmHg
(the ideal BP for people with lower risk of heart
disease or stroke)
- Due to Asian ethnicity, Caucasian physical
profile is different- bigger build.
Variations in BP

Persistant increase in BP

Damage to vessels; loss of elasticity;
decrease in blood flow to vital organs
Measurement of BP

Indirect


Most common, accurate estimate
Equipment

Sphygomanometer and stethescope
Measurement of BP

Direct




In patient setting only
Catheter is threaded into an artery under
sterile conditions
Attached to tubing that is connected to
monitoring system
Displayed as waveform on monitoring
screen
Other BP issues

Orthostatic or postural hypotension


Sudden drop in BP on moving from lying
to sitting or standing position
Primary or essential hypertension


Diagnosed when no known cause for
increase
Accounts for at least 90% of all cases of
hypertension
Remember the following for
accuracy of your readings

Instruct your
patients to avoid
coffee, smoking or
any other
unprescribed drug
with
sympathomimetic
activity on the day
of the
measurement
What Abnormal Results
Mean
Blood pressure

The minimal SBP
required to
maintain perfusion
varies with the
individual.
Interpretation of
low values must
take into account
the clinical
situation.
Blood pressure for adult

Physician will want
to see multiple
blood pressure
measurements
over several days
or weeks before
making a diagnosis
of hypertension
and initiating
treatment.
What Abnormal Results Mean

Pre-high blood
pressure: systolic
pressure
consistently 120 to
139, or diastolic 80
to 89

Stage 1 high blood
pressure: systolic
pressure
consistently 140 to
159, or diastolic 90
to 99
What Abnormal Results
Mean

Stage 2 high blood
pressure: systolic
pressure
consistently 160 or
over, or diastolic
100 or over
What Abnormal Results
Mean

Hypotension (blood
pressure below
normal): may be
indicated by a
systolic pressure
lower than 90, or a
pressure 25 mmHg
lower than usual
Hypertension

High blood pressure greater
than 139-89..
Blood pressure may be affected
by many different conditions
Blood pressure may be affected
by many different conditions



Cardiovascular
disorders
Neurological
conditions
Kidney and
urological disorders
Blood pressure may be affected
by many different conditions


Pre eclampsia in
pregnant women
Psychological
factors such as
stress, anger, or
fear
Eclampsia

END OF SLIDE