A detail introduction about sphygmomanometry along with this advancement.

1. SPHYGMOMANOMETRY
REETA KARKI

2. INTRODUCTION
Sphygmomanometry is the determination of blood pressure through
the use of a sphygmomanometer.
Sphygmos, pulse, + manos, rare, thin, + metron, measure

3. HISTORY
• The discovery of blood pressure has been attributed to the
Englishman Stephen Hales in 1773.
• In 1856, Faivre made the first accurate direct assessment of a human
patient’s BP by connecting an artery to a mercury manometer during
surgery.
• The forefather of modern sphygmomanometry was Riva Rocci.
• In 1905, the Russian physician N.C Karotkoff first reported the
auscultatory method of indirectly measuring BP.

4. CLINICAL SIGNIFICANCE
The prevalence rate of hypertension in the black population is
considerably higher than in the white population. Black develops
hypertension at the earlier age and it is likely to be more severe than in
other racial groups.
The systolic pressure is the pressure in the arteries, at the height of
pulsation, caused by cardiac contraction as the left ventricle pumps
blood into the aorta.
The diastolic pressure is the pressure in the arteries during
ventricular relaxation between cardiac contraction.

5. Indirect vs Direct Blood Pressure
Measurement
Direct blood pressure is measured through the use of catheter
inserted into a major artery that is usually connected to the
electronic-recording system.
Indirect blood pressure can be measured by using stethoscope and
sphygmomanometer.

6. The Karotkoff Sounds
• Karotkoff described the sound produced from the time the artery was
completely compressed until initial refilling occur.
• The first and last phases of these sounds, corresponding to the fist
audible detection to their disappearance, determine the systolic and
diastolic readings respectively which is expressed in mm of Hg.

7. The Karotkoff sounds
PHASE I Sudden appearance of clear, regular tapping sounds
PHASE II A swishing softening of sounds.
PHASE III Crisper sounds, increasing in intensity
PHASE IV Abrupt damping or muffling of sounds
PHASE V Complete disappearance of sound

8. INSTRUMENTATION
THEORY
 the circulatory mechanism is a closed system comprised of the
cardiac pump that forces a finite supply of blood through a complex
arterial tree.
 the systemic arterial bp represent the force applied against blood
vessel walls resulting from the direct effects of cardiac output(CO)
and peripheral vascular resistance(R).

9. Effects of cardiac output and Peripheral
vascular resistance
Cause Clinical example Effect
Increase CO Heavy exertion such as exercise Increased BP
Decrease CO Myocardial infarction Decreased BP
Increased R Peripheral vasocontriction from
sympathomimetics such as
phenylepinephrine
Increased BP
Decreased R Peripheral vasodilation from
sublingual nitroglycerin use
Decreased BP

10. Other factors contributing to arterial blood
pressure levels
Cause Clinical example Effect
Blood volume If reduced by major blood loss from
trauma or surgery
Decreased BP
Blood viscosity If elevated as measured by
hematocrit in polycythemia
Increased BP
Arterial wall elasticity If reduced because of
atherosclerosis
Increased BP

11. STETHOSCOPE
• The stethoscope is used to determine the systolic and diastolic
readings through auscultation of the Karotkoff sounds.
• It comprises of earpieces, binaurals, plastic or rubber tubing, and a
chest piece.

13. • The rubber or plastic coated earpieces should fit comfortably but snugly
to block out external noises.
• The binaurals are angled to follow the contour of the auditory canal.
• A spring clamp connecting the binaurals is often present to help maintain
tight contact with auditory openings.
• The chest piece has two components, a bell and a diaphragm.
• The diaphragm is the circular, flat-surfaced portion ending in a thin
plastic disk that transmit high frequency sounds.
• The bell side of the chest piece transmits low-frequency sounds.
• Depending upon the need of examiner, either the bell or diaphragm
portion is rotated or clicked into position so that sounds tranmit.

14. SPHYGMOMANOMETER
• The blood pressure cuff, or sphygmomanometer is comprised of a
non-stretchable fabric bag joining at the ends by Vecro cloth strips &
contains an inflatable rubber bladder.
• Connected to the cuff by one or more rubber tubes are an inflating
bulb, with a pressure release valve, and a manometer gauge.

15. • In the clinical setting, the cuff pressure is registered by either a mercury
or an aneroid manometer.
• The mercury manometer consists a narrow vertical column of Hg within a
glassor plastic tube that is set upright on a table top.
• Mercury manometer is the standard and accuracy is ensured when the
meniscus level reads zero when no pressure is applied and when the
column is observed to fall freely as the cuff pressure is released.
• The aneroid manometer consist a small metal bellows or spring that
moves a needle across a caliberated dial to register change in pressure.

16. The length of the arterial segment that is compressed by the inflated cuff
during BP measurement is one of the important factos influencing the
accuracy of the reading.
• Usually it has been determined that sphygmomanometry in the average
sized adult is most accurate when performed with a cuff 12 to 14 cm
wide.
• The cuff sizes mostly used in optometry practices are child, adult, and
thing for taking the BP of leg.

17. CATEGORIES OF AVAILABLE SPHYGMOMANOMETERS
1. Mercury Manometer
2. Aneroid Manometer
3. Electronic
4. Stationary automated
5. Automatic ambulatory

18. MERCURY MANOMETER

19. ANEROID MANOMETER

20. ELECTRONIC MANOMETER

21. DIFFERENT CUFF SIZES

22. CLINICAL PROCEDURE
• video

24. CLINICAL IMPLICATIONS
DIURNAL VARIATION
With use of an intra-arterial device continuously over a 24 hr period
in 20 untreated ambulatory hypertensives, Millar Craig et al. reported
that highest BP values in the mid-morning, a progressive fall
throughout the day, and lowest readings during sleep.

25. INTRAOBSERVER VARIABILITY
For variety of reasons, including errors in technique, inadequate training,
carelessness, digital preferencing, and preconceived expectations, blood
pressure readings have been found to vary widely between different observers.
Mitchell and Van Meter, in comparing sphygmomanometry readings obtained
by nursing personnel and the investigators, found differences of more than 15
mm Hg in 21% to 27% of the readings.

26. DIASTOLIC END POINT
Some conterversy persists over the correct and more accurate diastolic
reading, either phase IV Korotkoff (Diastolic I), when the muffling sound
first occurs, or the complete disappearance of sound of Phase V Korotkoff
(Diastolic II).
The American Heart Association recommends the Phase V be used as the
diastolic readings for adults except for those with hyperkinetic condition,
such as hyperthyroidism.
For hyperkinetic adult and for children Phase IV is recommended as the
diastolic end point.

27. DIFFERENCE IN RIGHT AND LEFT ARM READINGS
During initial visit, the bp of both arms should be measured.
If the difference in the readings is noted, the arm with higher reading is
used for future measurement.
A 5-10 mm Hg difference between two arm reading is within normal
limits.
Differences in the readings greater than 10-15 mm Hg could be indicative
of atherosclerotic narrowing of the subclavian or brachiocephalic arteries
as a part of subclavian steal syndrome.

28. WEAK OR INAUDIBLE KOROTKOFF SOUNDS
Elevating the patient’s arm before inflating the cuff will empty the blood
from foramen and will increase the gradient inflow between portions of
artery proximal and distal to the cuff.
Finally, inflating the cuff quickly will minimize the amount of blood
trapped in the forearm due to venous congestion that decreases the flow
gradient of arterial blood passing under the cuff during dflation and may
reduce audibility of the Korotkoff sounds.

29. ORTHOSTATIC(POSTURAL) HYPOTENSION
An adult whose bp is 95/60 or less, without a postural change, is
considered to be hypotensive.
As a patient changes from a lying or sitting position to a standing position,
the systolic pressure drops slightly or remains unchanged, whereas the
diastolic pressure rises slightly.
Orthostatic hypertension will be apparent by the changes in bp measured
in the supine, sitting, and standing position.

30. FALSELY LOW READINGS
FALSELY LOW READINGS
• Cuff too wide
• Deflating the cuff too rapidly(systolic)
• Patient’s arm above heart level
• Auscultatory gap

31. FALSELY HIGH READINGS
FALSELY HIGH READINGS
• Patient anxiety, fear, emotional stress
• Cuff too narrow or too loose
• Deflating the cuff too slowly
• Deflating the cuff too rapidly
• Patient’s arm below heart level
• Pseudohypertension

33. REFERENCES
• CLINICAL PROCEDURES IN OPTOMETRY
• INTERNET