3. WHAT IS BLOOD PRESSURE?
Blood pressure (BP) is a measure of the
force that the circulating blood exerts
against the arterial wall.
4. SYSTOLIC PRESSURE
• Systolic pressure is the maximum
pressure exerted by the blood against the
arterial walls.
• It results when the ventricles contract (
systole )
5. DIASTOLIC PRESSURE
• Diastolic Pressure is the lowest
pressure in the artery.
• It result when the ventricles are
relaxed (diastole )
6. British Hypertension Society classification of
blood pressure levels
Blood pressure Systolic BP (mmHg) Diastolic BP (mmHg)
<120 <80 Optimal
<130 <85 Normal
130-139 85-89 High normal
Hypertension
140-159 90-99 Grade 1 (mild)
160-179 100-109 Grade 2 (moderate)
>180 >110 Grade 3 (severe)
Isolated systolic hypertension
140-159 <90 Grade 1
>160 <90 Grade 2
7. •BP is measured in mmHg and recorded as systolic
pressure/diastolic pressure, together with where, and
how, the reading was taken, e.g. BP: 146/92 mmHg,
right arm, supine.
•BP is an important guide to cardiovascular risk and
provides vital information on the haemodynamic
condition of acutely ill or injured patients. BP constantly
varies and rises with stress, excitement and
environment.
8. Blood Pressure measurement
•Office BP measurement:
Two readings, 5 minutes apart, sitting.
•Ambulatory BP monitoring:
For white coat hypertension.
•Self-measurement of BP:
Information on response to therapy, may improve
adherence to therapy.
10. Time of measurement
• Use multiple readings at different times
during the waking hours of the patient.
• For patient taking antihypertensive
medications monitoring of blood pressure
should be done before taking the scheduled
dose.
11. Patient position
• BP should be measured in sitting position.
Patient should sit for 5 minutes before
measuring BP.
• In elderly, supine and standing position can
be used to detect postural hypotension.
12. Selecting the most accurate blood pressure cuff
• The length of the bladder should
be at least 80% of the
circumference of the upper arm.
• The width of the bladder should be
approximately 40% of the
circumference of the upper arm.
13. Where to listen for blood pressure sounds
From www.images.md
1- Locate the antecubital fossa of
the patient’s arm and palpate the
brachial artery. This location is
the point over which the
stethoscope is placed to listen for
Korotkoff sounds later.
2- Wrap the cuff approximately
2.5 inch above the antecubital
fossa.
14. Determining the palpated systolic pressure and
the maximum inflation level
From www.images.md
3. While palpating the radial
pulse, inflate the cuff until
you feel the radial pulse
disappear.
Note the pressure on the
manometer at this point and
rapidly deflate the cuff.
15. Measurement of BP
4- Place the stethoscope lightly over the brachial
artery and inflate the cuff to a pressure 30 mm Hg
greater than estimated systolic pressure.
5- Deflate the cuff slowly at a rate of 2 mm Hg per
heartbeat.
6- Systolic pressure equal the pulse first heard by
auscultation
16. 7- Deflate the cuff until the sounds become
muffled and then disappear.The disappearance
of sound estimate the diastolic pressure.
8- Record the blood pressure reading in even
numbers. Note patient’s position, cuff size, and
arm used for measurement.
17. Korotkoff sounds
These noises are produced from under the distal half of the BP
cuff between systole and diastole because the artery collapses
completely and reopens with each heartbeat. As the artery wall
rapidly opens it causes a snapping or tapping sound (like the sail of
a boat snapping in the wind).As the cuff pressure falls below the
diastolic pressure, the sound disappears as the vessel wall no
longer collapses but gently expands with each beat.The first
appearance of the sound (phase 1) indicates systole.As the
pressure is reduced, the sounds muffle (phase 4) and then
disappear (phase 5). Inter-observer agreement is better for phase
5 and this is recorded as diastolic BP. Occasionally muffled sounds
persist (phase 4) and do not disappear; in this case, record phase 4
as the diastolic pressure.
20. Common problems in BP
measurement
• BP different in each arm: A difference >10 mmHg suggests peripheral
vascular disease and raises the possibility of renal artery stenosis as the
cause of hypertension. Record the highest pressure and treat this
• Wrong cuff size: A cuff of 12.5 × 23 cm is suitable for only 60% of
Europeans.The bladder should encircle between 80% and 100% of the
arm. In obese patients with large arms a normal-sized cuff will over-
estimate BP and the error is greater when the centre of the cuff is not
over the brachial artery.Therefore for obese patients a larger cuff must
be used. Using too large a cuff produces only a small under-estimation
of BP (2-3 mm in systolic BP)
21. • Auscultatory gap: Up to 20% of elderly hypertensive patients
have phase 1 Korotkoff sounds which begin at systolic pressure
but then disappear for varying lengths of time, reappearing before
diastolic pressure. If the first appearance of the sound is missed,
the systolic pressure will be recorded at a falsely low level. Avoid
this by palpating the systolic pressure first
• Excess pressure of stethoscope: Excess pressure can artificially
lower the diastolic reading by 10 mmHg.The systolic pressure is
not usually affected
• Patient's arm at the wrong level: The patient's elbow should be
level with his heart. Hydrostatic pressure effects mean that if the
arm is 7 cm higher, both systole and diastole pressures will be 5
mmHg lower. If the arm is 7 cm lower than the heart, they will be
about 6 mm higher
22. • Postural change: When a healthy person stands, the pulse
increases by about 11 bpm and stabilizes after 1 min.The BP
stabilizes after 1-2 min. Check the BP after a patient has been
standing for 2 min; a drop of ≥20 mmHg on standing is postural
hypotension
• Abnormal pulse pressure: The pulse pressure is the difference
between the systolic and diastolic pressures. A pulse pressure of
≥80 mmHg suggests aortic regurgitation, while a low pulse
pressure may occur in aortic stenosis.
