blood pressure how to measure - ehs

Blood Pressure … How to MMeasure

Ahmed Khashaba, MDCardiology Department

Ain Shams University

Why !Why !Why ..!Why ..!

Control of Hypertension beginsControl of Hypertension beginsControl of Hypertension beginswithControl of Hypertension beginswith

accurate BP Measurement

with … with …

accurate BP Measurement

“Blood pressure measurement is oftenBlood pressure measurement is often considered “routine” and is often performed by those with the least training”

Jones DW, et al: Hypertension 2001; 37:185

Blood Pressure AssessmentBlood Pressure Assessment

Blood pressure of all adults should be measured by any trained healthcare professional whenever it i i tis appropriate.

Patients should be assessed at all appropriate Patients should be assessed at all appropriate medical visits

– To determine cardiovascular risk– To monitor antihypertensive treatment

SuspectsSuspects …

Equipment factorsq p

Observer factors

Patient factors

Sources of Error in BP Measurement

Single armSingle arm

Auscultatory gapAuscultatory gap

Conversation with Conversation with observersobservers

Quick deflationQuick deflationNo rest periodNo rest period

Atrial FibrillationAtrial FibrillationKorotkoff IVKorotkoff IV

Digit preference Digit preference White coat effect White coat effect

AlcoholAlcoholExpectation bias Expectation bias

Di iDi i

AlcoholAlcohol

CaffeineCaffeineDistractions Distractions

Background noiseBackground noiseSmokingSmoking

Full bowel/bladderFull bowel/bladder

Hearing acuityHearing acuityCrossed legsCrossed legs

Blood Pressure Assessment:P ti t ti d tPatient preparation and posture

Standardized technique:

Patient1. No caffeine in the preceding hour.2. No smoking or nicotine in the preceding 15-30 minutes.3. No use of substances containing adrenergic stimulants

h h l h i d h d i ( b such as phenylephrine or pseudoephedrine (may be present in nasal decongestants or ophthalmic drops).

4. Bladder and bowel comfortable.5 Q i t i t C f t bl t t5. Quiet environment. Comfortable room temperature.6. No tight clothing on arm or forearm.7. No acute anxiety, stress or pain.8 Patient should stay silent prior and during the procedure8. Patient should stay silent prior and during the procedure.

Blood Pressure Assessment:Patient preparation and posture


Posture

The patient should be calmly seated for at least 5 The patient should be calmly seated for at least 5 minutes, with his or her back well supported and arm supported at the level of the heart. His or her feet should touch the floor and legs should not be feet should touch the floor and legs should not be crossed.

The patient should be instructed not to talk prior The patient should be instructed not to talk prior and during the procedure.

Recommended Technique qfor Measuring Blood Pressure


• Use a mercury manometer or a recently calibrated aneroid or a validated calibrated aneroid or a validated electronic device.

• Aneroid devices should only be used if there is an established calibration check every 6-12 months.

Recommended Technique f i l dfor Measuring Blood Pressure

Electronic oscillometric devices:• Use a validated electronic device

according to BHS, AAMI or IP standards.

Office• For self blood pressure

measurement devices, a logo on the packaging ensures that this type of device and model meets the international standards for accurate blood pressure

tmeasurement.

AAMI=Association for the Advancement of Medical Instrumentation;

Home / Self

;BHS=British Hypertension Society; IP: International Protocol.

Recommended Technique qfor Measuring Blood Pressure (cont.)

Select aSelect acuff with the appropriate size

Cuff sizeCuff size

Arm circumference (cm) Size of Cuff (cm)

From 18 to 26 9 x 18 (child)

F 26 t 33 12 x 23 (standard From 26 to 33 12 x 23 (standard adult model)

From 33 to 41 15 x 33 (large obese)From 33 to 41 15 x 33 (large, obese)

More than 41 18 x 36 (extra large, obese)obese)

Recommended Technique Recommended Technique for Measuring Blood Pressure (cont.)

– Locate brachial and radial pulse

– Position cuff at the heart level

– Arm should be supported


– To exclude possibility of auscultatory gap, i ff increase cuff pressure rapidly to 20-30 mmHg above level of disappearance of radial pulse

– Place stethoscope over the brachial artery


– Drop pressure by 2 mmHg / secsec

• Appearance of sound (phase I Korotkoff) = systolic pressure

– Record measurement

– Drop pressure by 2 mmHg / beat

• Disappearance of sound (phase V pp (pKorotkoff) = diastolic pressure

–Record measurement

– Take 2 blood pressure measurements, 1 minute apart


Systolic BP200

180

No sound

Korotkoff sounds

y180

160

140

Clear sound Phase 1

Muffling Phase 2Auscultato

ry gapNo sound

Diastolic BP

120

100

80

Muffled sound

Muffled sound

Phase 3

Phase 4Diastolic BP

Possible readings:184 / 100

80

60

40 No sound Phase 5184 / 100136 / 100184 / 86 = correct136 / 86

20

0

mm Hg

Recommended Technique qfor Measuring Blood Pressure


• For initial readings, take the blood gpressure in both arms and subsequently measure it in the arm with the highest

direading.

Th ft t k t t • Thereafter, take two measurements on the side where BP is highest.


Record the blood pressure to the l t 2 H th closest 2 mmHg on the

manometer

as well as the arm used

and whether the patient was supine, sitting or standing.


• Avoid digit preference for preference for five (5) or zeros (0) by not rounding up or rounding up or down.

• Record the heart rate.


The seated blood pressure is used The seated blood pressure is used to determine and monitor treatment decisions.treatment decisions.

The standing blood pressure is used The standing blood pressure is used to test for postural hypotension, if present, which may modify the treatment.

Blood Pressure Assessment:Patient preparation and posture

Standing position

F ti t 65 di b ti d For patients over age 65, diabetics and patients being treated with antihypertensives check if there are antihypertensives, check if there are postural changes while taking blood pressure reading, i.e. after one to five minutes in the standing position and under circumstances when the patients

l i f t ti f complains of symptoms suggestive of hypotension.

Threshold for Initiation of Treatment and Target Values

Condition InitiationSBP / DBP

Target SBP / DBP mmHgSBP / DBP

mmHg

Diastolic ± systolic ≥ 140/90

SBP / DBP mmHg

<140/90

hypertension

Isolated systolic hypertension

SBP >160<140

<130/80hypertension

Diabetes ≥ 130/80Renal disease (≥ 130/80)

/

<130/80

<125/75(≥ 130/80)Proteinuria >1 g/day (≥ 125/75)

/

Blood pressure measurement with specific p pdevices

• Mercury Blood Pressure Monitor• Aneroid Blood Pressure Monitor• Aneroid Blood Pressure Monitor• Electronic Blood Pressure Monitor

Blood Pressure Measurement with Aneroid Blood Pressure Monitor

Aneroid devices shouldAneroid devices shouldnot be usedif there is notan established calibration checkevery 6-12 months.

The MessageThe Message …

BP measurement should not be performed lightly.BP measurement should not be performed lightly.p g y

Use standardized protocol

p g y

Use standardized protocol

The measurement of blood pressure through auscultation remains the most widely accepted method in everyday practice.

The measurement of blood pressure through auscultation remains the most widely accepted method in everyday practice.

Reliance on automated devices may lead to inaccurate readings in the presence of arrhythmias.

Reliance on automated devices may lead to inaccurate readings in the presence of arrhythmias.

Mercury sphyg. are still considered the gold-standard measuring devices for indirect blood pressure determination

Mercury sphyg. are still considered the gold-standard measuring devices for indirect blood pressure determinationp

Aneroid sphygmomanometers are considered accurate if calibrated with a mercury manometer at regular intervals

p

Aneroid sphygmomanometers are considered accurate if calibrated with a mercury manometer at regular intervalscalibrated with a mercury manometer at regular intervals.calibrated with a mercury manometer at regular intervals.

blood pressure how to measure - ehs

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