office and home blood pressure assessment hypertension diagnosis and follow up 2011 canadian...

Office and Home Blood Pressure Assessment

Hypertension Diagnosis and Follow up

2011 Canadian Hypertension Education Program Recommendations

Hypertension Canada and the Canadian Hypertension Education Program

Instructions for proper blood pressure measurement are found in the detailed recommendations of the CHEP

program (Can J Cardiol 2010;26(5):241-248), at www.hypertension.ca

http://www.hypertension.ca/

Blood Pressure Measurement and Hypertension Diagnosis

• 1 in 5 adult Canadians have hypertension• Over 40% of Canadians at aged 56-65 have

hypertension• 90% of normotensive persons aged 55-65 developed

hypertension in the next 20 years in the Framingham study

• Blood pressure of all adults should be measured by a trained healthcare professional at all appropriate visits:– To determine cardiovascular risk– To monitor antihypertensive treatment

• Blood pressure of adults with high normal blood pressure (130-139/80-89 mmHg) should be assessed annually

Blood Pressure Assessment

Wilkins et al. Health Reports Feb 2010

Prevalence of Hypertension in Canada

Mean systolic and diastolic BP by sex and age group, household population aged 20-79 years, March 2007 to February 2009

Prevalence of Hypertension in Canada

Wilkins et al. Health Reports Feb 2010

Life time Risk of Hypertension in Normotensive Women and men aged 65 years

Risk of Hypertension %

0 2 4 6 8 10 12 14 16 18 20

Years to Follow-up

Women

Risk of Hypertension %

Years to Follow-up

0 2 4 6 8 10 12 14 16 18 20

Men

JAMA 2002:297:1003-10. Framingham data.

100

80

60

40

20

0

100

80

60

40

20

0

Modifiable risks for developing hypertension

• Obesity• Poor dietary habits• High sodium intake• Sedentary lifestyle• High alcohol consumption

Development of hypertension (%) in people with high normal blood pressure

0

5

10

15

20

25

30

35

40

45

Year 1 Year 2 Year 3

Age 35-64

Age 65-94

Framingham cohort Vasan. Lancet 2001;358:1682-86

New onset hypertension in people with high normal blood pressure

• 772 subjects, overweight, mean age 48.5 • Not receiving treatment for hypertension• Average of 3 blood pressures at baseline:

– SBP 130-139 and DBP < 89 OR– SBP < 139 and DBP 85-89

• Primary endpoint – new onset hypertension

NEJM 2006;354:1685-97


0

20

40

60

80

YEAR 1 YEAR 2 YEAR 3 YEAR 4

New hypertension (%)

NEJM 2006;354:1685-97


• 40% of overweight patients with systolic 130-139 or diastolic 85-89 mmHg developed hypertension in 2 years and 63% in 4 years

• Annual follow-up of patients with high normal blood pressure is recommended by CHEP

Blood Pressure Assessment:Patient preparation and posture

Standardized Preparation:

Patient1. No acute anxiety, stress or pain.2. No caffeine, smoking or nicotine in the preceding

30 minutes.3. No use of substances containing adrenergic

stimulants such as phenylephrine or pseudoephedrine (may be present in nasal decongestants or ophthalmic drops).

4. Bladder and bowel comfortable.5. No tight clothing on arm or forearm.6. Quiet room with comfortable temperature 7. Rest for at least 5 minutes before measurement8. Patient should stay silent prior and during the

procedure.

Blood Pressure Assessment:Patient preparation and posture

Standardized technique:

Posture• The patient should be

calmly seated 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 crossed.

Blood Pressure Assessment:Patient position

X

Recommended Equipment for Measuring Blood Pressure

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

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

Recommended Equipment for Measuring Blood Pressure

Automated oscillometric devices:

• Use a validated automated device according to BHS, AAMI or IP clinical protocols.

• For home 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 measurement.

AAMI=Association for the Advancement of Medical Instrumentation;BHS=British Hypertension Society; IP: International Protocol.

Recommended Technique for Measuring Blood Pressure (cont.)

• Select a device with an appropriate size cuff

Use an appropriate size cuff

Arm circumference (cm) Size of Cuff (cm)

From 18 to 26 9 x 18 (child)

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

From 33 to 41 15 x 33 (large)

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

For automated devices, follow the manufacturer’s directions.

For manual readings using a stethoscope and sphygmomanometer, use the table as a guide.


• Locate the brachial pulse and centre the cuff bladder over it

• Position cuff at the heart level

• Arm should be supported

Recommended Technique for Measuring Blood Pressure* (cont.)

• To exclude possibility of auscultatory gap, increase cuff pressure rapidly to 30 mmHg above level of disappearance of radial pulse

• Place stethoscope over the brachial artery

*with manual or semi automated devices


• Drop pressure by 2 mmHg / beat

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

• Drop pressure by 2 mmHg / beat

– Disappearance of sound (phase V Korotkoff) = diastolic pressure

• Record measurement

• Take at least 2 blood pressure measurements, 1 minute apart

*with manual or semi automated devices

Korotkoff sounds and auscultatory gaps

Systolic BP

Diastolic BP

200

180

160

140

120

100

80

60

40

20

0

No sound

Clear sound

Clear sound

Muffled sound

No sound

Phase 1

Phase 3

Phase 4

Phase 5

Muffling Phase 2Auscultatory

gapNo sound

mmHg

Korotkoff sounds

Phase 4

Phase 3

Recommended Technique for Measuring Blood Pressure

Standardized technique:• For initial readings, take

the blood pressure in both arms and subsequently measure it in the arm with the highest reading.

• Thereafter, take two measurements on the side where BP is higher.


• Record the blood pressure to the closest 2 mmHg on the manometer

• and whether the patient was supine, sitting or standing.

Aneroid devices should not be used unless they are known to be in calibration and are checked regularly (minimally every 12 months).

* For manual blood pressure measurement


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

• Record the heart rate.

If the needle on an aneroid device is not zero it is inaccurate; however, the converse is not true.

* For manual blood pressure measurement


• The seated BP measurement is the standard position to determine diagnostic and therapeutic treatment decisions

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

Recommended Technique for Measuring BP: Standing BP

• Perform in patients – over age 65– with diabetes– if there are symptoms of postural hypotension

• Check after 1 to 5 minutes in the standing position and under circumstances when the patient complains of symptoms suggestive of hypotension

Diagnostic algorithm for high Blood Pressure including Office, ABPM and Home Blood Pressure Measurement

Elevated Out of the Office BP

measurement

Elevated Out of the Office BP

measurement

Elevated Random Office BP

Measurement

Elevated Random Office BP

Measurement

Hypertension Visit 1BP Measurement,

History and Physical examination



Hypertension Visit 2within 1 month

Yes

BP ≥ 140/90 mmHg and Target organ damage or

Diabetes or Chronic Kidney Disease or BP ≥ 180/110?

BP ≥ 140/90 mmHg and Target organ damage or

Diabetes or Chronic Kidney Disease or BP ≥ 180/110?

Diagnostic tests orderingat visit 1 or 2

Diagnostic tests orderingat visit 1 or 2

HypertensiveUrgency /

Emergency


Emergency

Diagnosisof HTN

Diagnosisof HTN

BP: 140-179 / 90-109BP: 140-179 / 90-109

No

HTN = hypertension


BP: 140-179 / 90-109BP: 140-179 / 90-109

ABPM (If available)ABPM (If available)Clinic BPMClinic BPM HBPM HBPM

Yes

Hypertension Visit 2Target Organ Damage

or Diabetesor Chronic Kidney Disease

or BP ≥ 180/110?

Hypertension Visit 2Target Organ Damage

or Diabetesor Chronic Kidney Disease

or BP ≥ 180/110?






Emergency


Emergency

Diagnosisof HTN

Diagnosisof HTN

No

HBPM = Home Blood Pressure Measurement


BP: 140-179 / 90-109BP: 140-179 / 90-109

ABPM (If available)ABPM (If available)Clinic BPClinic BP HBPM HBPM

Diagnosisof HTN

Awake BP≥ 135 SBP or

≥ 85 DBPOr 24-hour

≥ 130 SBP or≥ 80 DBP

Awake BP≥ 135 SBP or

≥ 85 DBPOr 24-hour


Awake BP< 135/85 and

24-hour< 130/80

Awake BP< 135/85 and

24-hour< 130/80

Continue to follow-up

Diagnosisof HTN

Hypertension visit 3

≥ 160 SBP or ≥ 100 DBP


< 140 / 90

Diagnosisof HTN


< 160 / 100

Hypertension visit 4-5

ABPM or HBPMor

≥ 135 SBP or ≥ DBP 85

≥ 135 SBP or ≥ DBP 85

< 135/85 < 135/85

Diagnosisof HTN


or

The concept of masked hypertension

From Pickering, Hypertension 1992

Office SBP mmHg

Ho

me

or

day

tim

e A

BP

M S

BP

m

mH

g

Truehypertensive

TrueNormotensive White Coat HTN

Masked HTN

135

140

135

140

The prognosis of masked hypertension

Prevalence of masked hypertension is approximately 10% in the general population (prevalence is higher in diabetic patients).

0

0.5

1

1.5

2

2.5

Normotension White CoatHypertension

MaskedHypertension

Hypertension

Relative risk ofCVD

J Hypertension 2007;25:2193-98

Threshold for Initiation of Treatment and Target Values

Condition Initiation

SBP / DBP mmHg

Diastolic ± systolic hypertension 140/90

Isolated systolic hypertension SBP >160

Home BP measurement (no diabetes, renal disease or proteinuria)

( 135/85)

Diabetes or chronic kidney disease 130/80

Target

SBP / DBP mmHg

<140/90

<140

<135/85

<130/80

VII. Home measurement of blood pressure

• Home BP measurement should be encouraged to increase patient involvement in care

• Which patients?– For the diagnosis of hypertension– Suspected non adherence– White coat hypertension or effect– Masked hypertension

Average BP equal to or over 135/85 mmHg should be considered elevated

Benefits of Home Blood Pressure Monitoring

• Rapid confirmation of the diagnosis of hypertension• Better prediction of cardiovascular prognosis• Diagnosis of white coat and masked hypertension• Reduced medication use in white coat effect• Improved adherence to drug therapy• Better blood pressure control

Not all patients are suited to home measurement

• Undue anxiety in response to high blood pressure readings

• Physical or mental disability prevents accurate technique or recording

• Arm not suited to blood pressure cuff (e.g. conical shaped arm)

• Irregular pulse or arrhythmias prevent accurate readings

• Lack of interest

The vast majority of patients can be trained to measure blood pressure

Average home BP > 135/85 mmHg should be considered elevated

Home Measurement of BP:Use validated BP measurement devices

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

* Endorsed by the Canadian Hypertension Society

VII. Suggested Protocol for Home Measurement of Blood Pressure for the Diagnosis of Hypertension

• Home blood pressure values should be based on:– duplicate measures,– morning and evening,– for an initial 7-day period.

• Singular and first day home BP values should not be considered.

• Daytime average BP equal to or over 135/85 mmHg should be considered elevated

Home Measurement of BP:Patient Education

How to?• Use devices:

– appropriate for the individual – appropriate cuff size– marked with this symbol

• Adequate patient training in:– measuring their BP– interpreting these readings

• Regular verification– measuring techniques

Home measurement can help to improve patient adherence

Values > 135 / 85 mmHg

should beconsidered elevated

Suggested Protocol for Home Measurement of Blood Pressure

How?• Home blood pressure values for assessing white coat

hypertension or sustained hypertension should be based on:– Duplicate measures,– Morning and evening,– For an initial 7-day period.

• Single readings and first day home BP values should not be considered

VII. Home Measurement of BP: Patient Education

• Assist patients to select a model with the correct size of cuff– Measure and record the patients mid arm circumference so they can

match it to cuff size

• Recommend devices listed at www.hypertension.ca or marked with this symbol

• Ask patients to carefully follow the instructions with device and to record only those blood pressure readings where they have followed recommended procedure

• Advise patients that average readings equal to or over 135/85 mmHg are high– a lower threshold is appropriate for those with diabetes or chronic

kidney diseaseHome measurement can help to improve patient adherence

Values equal to or over135 / 85 mmHg

should beconsidered elevated for those without diabetes

or chronic kidney disease


Web based home monitoring

A website to assist patients to monitor and track home blood pressure and support self management

including healthy lifestyle change is available at: www.heartandstroke.ca/BP

http://www.heartandstroke.ca/BP

Advice for patients on when to contact a health care professional based on high average home blood pressure readings*

Systolic BP (mmHg) Diastolic BP reading

Less than 130 Less than 85 Usual follow-up

130-179* 85-109* Check reading again using the correct technique. If the readings remain high, discuss with your healthcare provider at your next regularly scheduled appointment

180 – 199* 110-119 Check reading again using the correct technique. If the readings remain high, schedule an appointment with your doctor to discuss your treatment plan.

More than 200* More than 120 Check reading again using the correct technique. If the readings remain high, schedule an urgent appointment with your doctor to discuss your treatment plan.

*(available at www.hypertension.ca in the resource section under educational tools for health care professionals in the Brief Hypertension Action Tool or at www.heartandstroke.ca/BP)

*Patients with diabetes, chronic kidney disease or who are at high risk of cardiovascular events require individualized advice.




Home measurement of blood pressure

A poster and instruction sheets can be ordered at: www.hypertension.ca


Suggested use of ABPM in the Management of Hypertension

Adapted from White W, NEJM 348:24, June 12, 2003

ABPM: Ambulatory Blood Pressure Monitoring BP: Blood Pressure

Office BP > 140/90 mmHgin low risk patients (with no target-organ disease)

Home-monitored blood pressure <135/85mmHg

Perform ABPM

Mean awake BPLess than 135/85 mmHg

Follow-up with periodic home-BP measurement and or

repeated ABPM every 1-2yr.

Mean awake BP equals or over 135/85 mmHg

Home-monitored blood pressure equals or over 135/85mmHg

Initiate antihypertensive therapy

Recommendations for Follow-up

Are BP readings below target during 2 consecutive visits?

Non Pharmacological treatment

With or without Pharmacological treatment

Diagnosis of hypertension

Follow-up at 3-6 month intervals

Symptoms, Severe hypertension, Intolerance to anti-hypertensive

treatment or Target Organ Damage

NoYes

NoYes

More frequentvisits

Visits every 1-2 Months

Blood pressure measurement with specific devices

• Mercury Blood Pressure Monitor• Aneroid Blood Pressure Monitor• Automated Blood Pressure Monitor

Blood Pressure Measurement with Mercury Blood Pressure Monitor

• The patient should – Be calmly seated for at least 5 minutes– Have their back supported with a chair

back– Have their arm bare or have thin clothing

on– Have their arm supported at the level of

the heart. – Have their feet on the floor and their legs

should not be crossed.

– Not talk prior and during the procedure.

• The column of mercury must be vertical, and at the observers eye level


• Use a cuff with the appropriate size

• Estimate the systolic beforehand:– Palpate the brachial artery

– Inflate cuff until pulsation disappears

– Deflate cuff

– Estimate systolic pressure

• Inflate to 30mmHg above the estimated systolic level needed to occlude the pulse


• Place the stethoscope diaphragm over the brachial artery and deflate at a rate of 2mmHg/beat until you hear regular tapping sounds. Measure systolic (first regular sound) to nearest 2mmHg

• Deflate at a rate of 2 mmHg/heart beat to 10 mmHg below the last heard Korotkoff sound

• Measure diastolic blood pressure to nearest 2mmHg.

Blood Pressure Measurement with Aneroid Blood Pressure Monitor

• The patient should – Be calmly seated for at least 5 minutes

– Have their back supported with a chair back

– Have their arm bare or have thin clothing on

– Have their arm supported at the level of the heart

– Have their feet on the floor and their legs should not be crossed

– Not talk prior and during the procedure.

• The manometer should be easily visible at the observer’s eye level


Use of standardized measurement techniques is recommended when assessing blood pressure

• When using automated office oscillometric devices such as the BpTRU, the patient should be seated in a quiet room (no specified period of rest). With the device set to take measures at 1 or 2 minute intervals, the first measurement is taken by a health professional to verify cuff position and validity of the measurement. The patient is left alone after the first measurement while the device automatically takes subsequent readings.

• The BpTRU automatically discards the first measure and averages the next 5 measures.


• Estimate the systolic beforehand:a) Palpate the brachial artery

b) Inflate cuff until pulsation disappears

c) Deflate cuff

d) Estimate systolic pressure when the pulse reappears

• Inflate to 30mmHg above the estimated systolic level needed to occlude the pulse



• Place the stethoscope diaphragm over the brachial artery and deflate at a rate of 2mmHg/beat until you hear regular tapping sounds. Measure systolic (first regular sound) to nearest 2mmHg

• Deflate at a rate of 2mmHg/beat until disappearance. Measure diastolic blood pressure to nearest 2mmHg



• Aneroid devices should not be used unless they are known to be in calibration and are checked regularly (minimally every 12 months).

• If the needle on an aneroid device does not zero it is inaccurate; however the converse is not true.

Assessing the calibration of an aneroid device

• Attach the aneroid device and cuff to a mercury manometer using tubing and if necessary a ‘Y’ or ‘T’ connection (see diagram). Consider putting cotton wool in the T tube to prevent the mercury from oxidizing and becoming contaminated.

• Pump the cuff up and assess the pressure of the aneroid at 20 mmHg intervals from 300 mmHg to 60 mmHg.

• The aneroid is out of calibration if the readings are 4 or more mmHg different from the mercury device.

• Do not use the aneroid device if it reads 4 or more mmHg different from the mercury device at pressures where diagnosis or therapeutic decisions are made.

Note: If the aneroid device does not read ‘0’ when there is no pressure in the cuff it is out of calibration

Attaching an aneroid device to a Mercury device for calibration testing

Note: check the mercury column is at zero before testing.

Blood Pressure Measurement with a Fully Automated Home or Office Automated Blood Pressure Monitor

• The patient should be calmly seated for at least 5 minutes, with their back well supported and arm supported at the level of the heart. Their feet should touch the floor and legs should not be crossed. The patient should be instructed not to talk prior and during the procedure.

• Ensure no tight clothing constricts the arm

• Use a cuff with the appropriate size

• Place the cuff on snuggly with the indicator mark on the cuff over the brachial artery

• Take at least two blood pressure measurements 1 minute apart

• Record measurement as displayed

Recommended automated blood pressure monitors for home blood pressure measurement

Monitors A&D® or LifeSource® Models: 705, 767, 767PAC, 767Plus, 774, 774AC, 779, 787, 787ACMonitors Omron® Models: HEM-705 PC, HEM-711, HEM-741CINTMonitors Microlife® or Thermor® (also sold under different brand names)Models: BP 3BTO-A, BP 3AC1-1, BP 3AC1-1 PC, BP 3AC1-2, BP 3AG1, BP 3BTO-1,BP 3BTO-A (2), BP 3BTO-AP, RM 100, BP A100 Plus, BP A 100

• For your patients – ask them to sign up at www.myBPSite.ca for free access to the latest information & resources on high blood pressure

• For health care professionals – sign up at www.htnupdate.ca for automatic updates and on current hypertension educational resources

http://www.mybpsite.ca/

http://www.htnupdate.ca/

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