HYPERTENSION Measurement of Blood Pressure

Mohammad Ilyas, M.D.

Assistant Clinical Professor

University of Florida / Health Sciences Center

Jacksonville, Florida USA

6/30/2014

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Outline

1. Definition, Regulation and Pathophysiology

2. Measurement of Blood Pressure, Staging of Hypertension and Ambulatory

Blood Pressure Monitoring

3. Evaluation of Primary Versus Secondary

4. Sequel of Hypertension and Hypertension Emergencies

5. Management of Hypertension (Non-Pharmacology versus Drug Therapy)

6. The Relation Between Hypertension: Obesity, Drugs, Stress and Sleep

Disorders.

7. Hypertension in Renal diseases and Pregnancies

8. Pediatric, Neonatal and Genetic Hypertension

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History of Blood Pressure Measurement

Stephen Hales 1733

Hollow glass tube in neck

artery of horse

Blood rose 9 feet in glass tube

Medicine, an Illustrated History 1987 6/30/2014

3

History of Blood Pressure Measurement

1896. Scipione Riva-Rocci

Only Systolic BP measured

by palpation

Medicine, an Illustrated History 1987 6/30/2014

4

Measurement of Blood Pressure

Correct measurement and interpretation of the blood

pressure (BP) is essential in the diagnosis and management

of hypertension.

It is essential that BP machines are properly calibrated,

appropriate cuff sizes are selected, and,

when BP is measured in an office-based setting

personnel are properly trained and

the patient is positioned correctly.

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Measuring accurate BP’s

Cuff too small → falsely high reading

Cuff too big → OK reading or no reading

(usually not falsely low)

Lower extremities - Normally, BP is 10 to 20

mmHg higher in the legs than the arms

Prefer arm if at all possible

Right arm for comparison with standards

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Blood Pressure Cuff size

• Bladder width >

40% of mid-arm

circumference.

• Bladder length

80-100% of arm

circumference.

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Blood Pressure Cuff Size

Index line

Bladder length (80%) 20%

Largest allowable mid arm

circumference for bladder (100%)

MAC = Mid Arm Circumference

Cuff length = 80% of MAC

Cuff width = 40% of MAC MAC

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Confirming High BP’s

Repeat BP in both arms and one leg (both

not usually necessary)

Repeat 3 times to assure accurate

Dx of HTN requires elevated BP’s on 3

separate occasions

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Disappearance of “HTN” with

Repeated Measurement

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METHODS FOR THE DIAGNOSIS OF

HYPERTENSION

Hypertension can be diagnosed using one of the

following three acceptable measurement

strategies:

Office-based blood pressure measurements

Home blood pressure monitoring

Ambulatory blood pressure monitoring (ABPM)

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Effect of Training on Observer Errors

Bruce NG et al. J Hypertens 1988; 6:375- 380

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New Blood Pressure Norms

OPTIMAL

<120 and <80

HIGH NORMAL

130-139 or 85-89

STAGE 1

140-159 or 90-99

STAGE 2

160-179 or 100-109

STAGE 3

≥180 or ≥110

NORMAL

<130 and <85

NORMAL

<120 and <80

PRE-HYPERTENSION

120-139 OR 80-89

STAGE 2

≥160 or ≥100

STAGE 1

140-159 or 90-99

JNC 7 (2003) JNC 8 (2013) JNC 6 (1997)

Hy

pe

rte

nsi

on

JNC VI. Arch Intern Med. 1997;157:2413-2446

JNC 7. JAMA. 2003;289(19):2560-2572.

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New Blood Pressure Norms for Children Normotensive

Average SBP and DBP <90th % for age, sex and height

Pre-hypertension

Average SBP or DBP >90th but <95th percentile (OR >120/80)

Hypertension

Average SBP and/or DBP >95th percentile for age, sex and height on 3 separate occasions

Stage 1: 95th-99th percentile + 5 mmHg

Stage 2: >99th percentile + 5 mm Hg

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How to use the percentile tables?

Need:

Age, gender, height percentage

BP charts

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7 yo boy

Ht 75%tile

http://www.cc.nih.gov/ccc/pedweb/pedsstaff/bptable1.PDF

50% 99/58

90% 113/73

95% 119/80

99% 127/88

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BP tables for Infants

*Task Force on Blood Pressure Control in Children. Report of the Second Task Force on Blood Pressure Control in Children—1987.Pediatrics.1987;79:1–25(PR)

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Devices

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DINAMAP

Oscillometric wrist BP monitor

Ambulatory BP monitor

Mercury sphygmanometer

Aneroid BP monitor

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Which blood pressure apparatus is the “Gold standard”

for BP measurement in children above age 3?

A. DINAMAP

B. Oscillometric wrist BP monitor

C. Ambulatory BP monitor

D. Mercury sphygmanometer

E. Aneroid BP monitor

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Mercury Sphygmomanometer

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Mercury Sphygmomanometry

1998: EPA and the American Hospital

Association agreed to virtually eliminate

mercury from hospitals by 2005

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Aneroid Manometer

Mercury pressure gauge

replaced by mechanical

spring

Gauges are often small

Accuracy varies among

manufacturers

Requires frequent calibration

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Aneroid Manometers

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Mercury and Aneroid Manometer

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Testing the Aneroid Manometer

Does the needle rest at zero?

Inflate to 200 mm Hg. Wait for 1 minute, if lower than 170 suspect leak

Using the Y connector, connect to mercury device and check readings

If any reading is off by >4 mm, remove from service

Date the calibration

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Oscillometric Devices

Office Use

Expensive (approximately $3000)

Many have been validated (BHS, AAMI)

Recommended for children of all ages

Home Use

Relatively inexpensive

Few have been validated in children

Not recommended for ages < 4 years

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Oscillometric Devices

Measure mean arterial pressure (MAP)

and calculates SBP and DBP

The algorithms used are proprietary and NOT

standardized

Results can vary widely and they do not

always closely match BP values obtained by

auscultation

These machines must be calibrated regularly 6/30/2014

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Dinamap® Oscillometric Device

Dinamap® is an

acronym for:

Device for

Indirect

Noninvasive

Mean

Arterial

Pressure

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Manual vs. Automatic

Manual is the gold standard

Oscillometric measurements preferred in infants

and ICU settings ONLY

All high readings should be confirmed with a

manual

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Oscillometric Devices

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What is being measured?

Auscultatory method: relies on relationship

between audible Korotkoff sounds and pressure

at systole and diastole

Oscillometric method: relies on the amplitude of

oscillations in the arterial wall to determine MAP

(maximum amplitude); complex and proprietary

algorithms used to estimate SBP and DBP

Mean arterial pressure (MAP) is average pressure

throughout the cardiac cycle.

MAP=(SBP)+2(DBP)/3 6/30/2014

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Ambulatory BP Monitoring

Oscillometric or acoustic methods

24 hour monitoring

Individual measurements not more accurate

Readings downloaded into PC

Cost: $2500-4500

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Ambulatory Blood Pressure Monitoring

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White Coat Hypertension

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Ambulatory Blood Pressure Monitoring

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Blood pressure is measured in preferably

on ?

A. Right lower leg

B. Left upper arm

C. Right upper arm

D. Left wrist

E. Right wrist

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Auscultatory Method

Sitting quietly for 5 minutes

Back supported and feet on the floor

Right arm supported, cubital fossa at

heart level

Estimate systolic BP by palpation, re-inflate

cuff to 20 mmHg higher

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What is the optimal rate of deflation of

blood pressure cuff?

A. 1 mm Hg/sec

B. 2-3 mm Hg/sec

C. 5 mm Hg/sec

D. 10 mm Hg/sec

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Auscultatory Method

Deflate cuff at 2-3 mmHg/sec

Systolic BP= onset tapping sounds*

Diastolic BP= disappearance of sounds (fifth Korotkoff sound)

Record BP twice on each occasion as right arm, sitting, SBP/DBP(K5), average used to estimate BP level

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Characteristics of Korotkoff sounds.

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Auscultatory Method

DBP is determined by disappearance of

Krotkoff sounds (K5)

Sometime Krotkoff sounds heard till 0 mm Hg

Try less pressure on the head of stethoscope

If K5 still persists K4 should be recorded as DBP

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Fourth report on BP. Pediatrics August 2004

Summary

Accurate blood pressure measurement is the

corner stone of diagnosis of hypertension

Oscillatory method can be used for screening but

elevated blood pressure should be confirmed with

auscultatoy method

Appropriately sized cuff is mandatory and measure

mid arm circumference to choose the cuff size

Calibrate BP measurement apparatus semiannually

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Quizzes

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Quiz 1. When Measuring the Blood Pressure

all statement below are true EXCEPT

A. Correct measurement of the blood pressure (BP) is

essential in the diagnosis and management of

hypertension.

B. It is essential that BP machines are properly calibrated.

C. Appropriate cuff sizes are needed for children

D. When BP is measured in an office-based setting,

personnel training does not interfere the measurement.

E. The position of patient impact the BP readings.

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Quiz 1. When Measuring the Blood Pressure

all statement below are true EXCEPT

A. Correct measurement of the blood pressure (BP) is

essential in the diagnosis and management of

hypertension.

B. It is essential that BP machines are properly calibrated.

C. Appropriate cuff sizes are needed for children

D. When BP is measured in an office-based setting,

personnel training does not interfere the measurement.

E. The position of patient impact the BP readings.

6/30/2014

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Quiz 2. All statements below are true,

EXCEPT

A. Cuff too small lead to falsely high BP reading

B. Cuff too big usually not lead to falsely low BP

reading

C. Lower extremities BP reading is 10 to 20 mmHg

lower than the arms

D. Right arm is the prefer arm if at all possible

E. Right arm for comparison with standards

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Quiz 2. All statements below are true,

EXCEPT

A. Cuff too small lead to falsely high BP reading

B. Cuff too big usually not lead to falsely low BP

reading

C. Lower extremities BP reading is 10 to 20 mmHg

lower than the arms

D. Right arm is the prefer arm if at all possible

E. Right arm for comparison with standards

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Quiz 3. Which of the following Staging of

Hypertension is not TRUE ?

A. Normal Blood pressure is systolic <120 and

diastolic < 80

B. Pre hypertension include systolic 120-140 and

diastolic 80-90

C. Stage 1 hypertension is systolic > 150

D. Stage 1 hypertension is diastolic > 90

E. Stage 2 hypertension is Systolic > 160

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Quiz 3. Which of the following Staging of

Hypertension is not TRUE ?

A. Normal Blood pressure is systolic <120 and

diastolic < 80

B. Pre hypertension include systolic 120-140 and

diastolic 80-90

C. Stage 1 hypertension is systolic > 150

D. Stage 1 hypertension is diastolic > 90

E. Stage 2 hypertension is Systolic > 160

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QUIZ 4. What is being measured?

TRUE / FALSE

A. Auscultatory method relies on relationship between

audible Korotkoff sounds and pressure at systole and

diastole.

B. Oscillometric method relies on the amplitude of

oscillations in the arterial wall to determine MAP

(maximum amplitude).

C. Mean arterial pressure (MAP) is average pressure

throughout the cardiac cycle.

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QUIZ 4. What is being measured?

TRUE / FALSE

A. Auscultatory method relies on relationship between

audible Korotkoff sounds and pressure at systole and

diastole. TRUE

B. Oscillometric method relies on the amplitude of

oscillations in the arterial wall to determine MAP

(maximum amplitude). TRUE

C. Mean arterial pressure (MAP) is average pressure

throughout the cardiac cycle. TRUE

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