2. Stephen Hales
⢠1727- First Blood
Pressure measurements
by inserting glass tubes
inside arteries of a Mare
and recording pressure
from the column of
blood that rose
6. Palpatory Method
⢠Rough Estimation of Systolic Pressure
⢠Carotid Femoral radial >70 mm Hg
⢠Carotid and Femoral > 50 mm Hg
⢠Carotid >40 mm Hg
Deakin CD, Low JL (September 2000). Accuracy of advanced trauma life
support guidelines for predicting systolic blood pressure using carotid,
femoral and radial pulses: Observational ; BMJ 321 (7262): 673â4.
7. Direct Method
⢠Direct Intra arterial Measurement of
Pressure using a pressure transducer
⢠Systolic is recorded 5-10 mm Hg higher and
Diastolic is 5-10 mm lower than non- invasive
techniques
⢠Gold Standard
⢠Accurate beat-to-beat monitoring
Matthew Ward, Jeremy A Langton,
Disclosures Cont Edu Anaesth Crit Care and Pain. 2007;7(4):122-126.
8. Mercury Sphygmomanometer
⢠Samuel Siegfried Karl
Ritter von Basch
(1881)
⢠Riva Rocci (1896)
⢠Modern Version by
Harvey Cushing
(1901)
GOLD STANDARD IN CLINICAL PRACTICE
9. Aneroid Sphygmomanometer
⢠No Mercury
⢠Metal Bellow and
Lever system
⢠Inaccurate if not
calibrated
.
Mion D, Pierin AM. How accurate are sphygmomanometers? J Hum
Hypertens. 1998; 12: 245â248
Yarows SA, Qian K. Accuracy of aneroid sphygmomanometers in clinical
usage: University of Michigan experience. Blood Press Monit. 2001; 6:
101â106.
10. Hybrid BP monitors
⢠Combine features of mercury and aneroid
sphygmomanometers
⢠Mercury replaced by Electronic Pressure
Gauge
⢠Auscultatory method used
11. PHYSICS OF BP MEASUREMENT
⢠Reynolds number
Re = Ď D v
Îź
Ď- Density of the fluid
D- Diameter of the vessel
V- Velocity of the fluid
Îź- Viscosity of the fluid
Re < 2100 â Laminar flow
Re > 4000- Turbulent flow
18. Subject Position
⢠Quitely Seated atleast for 5 min in a chair
⢠Feet on the floor
⢠Arms at Level of Right Atrium (mid point of
sternum)
⢠Avoid Caffeine, Exercise and Smoking 30
min prior to recording
19. Body Position
⢠Back supported
⢠Legs Uncrossed
⢠Arm supported
⢠Cuff at level of Right
Atrium- Midpoint of
the Sternum
20. ⢠Arm to be at level of
right atrium even
when patient is
supine (P=hĎg)
⢠Support with pillow
23. Arm
Circumference
Cuff Cuff Size
Upto 10 cm Newborn 4X8 cm
11-15 cm Infant 6X12 cm
16-21 cm Child 9X18 cm
22-26 cm Small Adult 12 X22 cm
27-34 cm Adult 16X30 cm
35-44 cm Large Adult 16X36 cm
45-52 cm Adult Thigh 16X 42 cm
24. Cuff Placement
⢠Midline of bladder of
cuff over arterial
pulsation
⢠Lower end 2-3 cm
above cubital fossa
⢠Midthigh level in lower
limb
27. Position of Eye of Observer
⢠Eye at level of
upper meniscus of
mercury column
28. Inflation and Deflation
⢠Initial Inflation atleast 30 mm above point
where radial pulse disappears
⢠Deflation at 2-3 mm per second
⢠First and Last sounds to be taken as
systolic and Diastolic Pressures
⢠Column to be read to nearest 2mm Hg
29. Number of Measurements
⢠Minimum of two readings at least
intervals of atleast one min
⢠Average of both readings to be taken
⢠If diff > 5 mm Hg, more readings to be
taken and averaged out
30. Both Arm Measurements
⢠Ideally, first visit should include
measurement of blood pressure in both
arms
⢠If Consistent difference in measurements
without identifiable cause, higher reading
should be used as baseline
31. Blood Pressure in Paediatric Age
Group
⢠BP in all four limbs to be checked on first
visit
⢠Auscultatory method satisfactory
⢠Doppler
⢠Oscillometric Most accurate
⢠Palpatory method for systolic pressure
⢠Flush method for infants â Systolic only
32. Self Monitoring at Home
⢠Useful in White Coat Hypertension
⢠Smokers
33. Continuous Ambulatory BP
⢠White Coat Hypertension
⢠Drug Resistance
⢠Hypotension with Anti hypertensive
therapy
⢠Episodic Hypertension
⢠Autonomic Dysfunction
34. TAKE HOME MESSAGE
⢠Comfortable Sitting position of Subject
⢠Appropriate Cuff Size
⢠Calibrated Instrument
⢠Proper Inflation and Deflation Procedure
⢠Average of Readings