APPROACH TO HYPERTENSION

DEFINITION• Persistent elevation of

– Systolic BP of 140 mmHg or greaterAnd/ or

– Diastolic BP of 90 mmHg or greaterBP (mmHg) systolic diastolic

Normal <120 <80

Pre hypertension 120-139 80-89

HPT Stage 1 140-159 90-99

HPT Stage 2 ≥160 ≥100

Based on average of two or more properly measured, seated BP readings on 2 or more office readings

Patient Evaluation

• Objectives:– To assess lifestyle and identify cardiovascular risk

factors or concomittant disorder that may affect prognosis and treatment

– To reveal identifiable cause of HPT– To assess the presence of target organ damage.

TARGET ORGAN DAMAGE (TOD)

• Heart– Left ventricular hypertrophy– Angina or prior myocardial infarction– Prior coronary revascularization– Heart failure

• Brain– Stroke or transient ischaemic attack

• Chronic kidney disease• Peripheral artery disease• Retinopathy

SECONDARY CAUSES• Sleep apnoea• Drug-induced or drug-related• Chronic kidney disease• Renovascular disease• Endocrinopathies

– Primary aldosteronism– Phaeochromocytoma– Cushing syndrome– Acromegaly– Thyroid and parathyroid disease

• Coarctation of the aorta• Takayasu arteritis

HISTORY

• Duration and level of elevated BP if known• Symptoms of secondary causes of HPT• Symptoms of target organ damage• Symptoms of concomitant disease• Family history• Dietary history• Drug history• Lifestyle and social history

PHYSICAL EXAMINATION

• General (height, weight, waist circumference)• Appropriate BP measurements• Fundoscopy-hypertensive retinopathy:

– grade 1: tortous artery– grade 2: A-V nipping, – grade 3: flame hemorrhage and cotton woolspots, – grade 4: papillloedema

• Bruit and peripheral pulses• Systems examination (cardiovascular, respiratory,

abdomen, neurological examinations)• Lower limb edema

INVESTIGATIONS• Full blood count• Renal function tests ( urea, creatinine, serum

electrolytes, and uric acid)• Urinalysis• ECG• Chest x-ray

Lifestyle modification

Not at Goal BP

Initial drug choices

With compelling indication

Drugs for the compelling indication

Without compelling indication

Stage II

-2-drugs combination-Usually thiazide diuretics with ACE-i/ARB/BB/CCB

Stage I

-Thiazide diuretics-May consider ACE-I, ARB, BB, CCB or combinations

Optimize dosage, add additional drugs, consider consultation with HPT specialist

Not at Goal BP

JNC 7

TREATMENT

• LIFESTYLE MODIFICATION– Reduction of weight– Adopt DASH eating plan– Dietary sodium reduction– Physical activity– Reduction of alcohol consumption

• PHARMACOLOGIC – ACE-I, ARB, BB, CCB, Diuretics

Lifestyle Modification

• Weight reduction– As far as possible, aim ideal BMI– Asians – 18.5 – 23.5 kg/m2

– Reduction of 5-10% in 6-12 months– As little as 4.5 kg significantly reduce BP

• Sodium intake restriction– Intake of <100 mmol of sodium or 6g of sodium

chloride a day (<1¼ tsp of salt)

Lifestyle Modification

• Avoidance of alcohol– Intake ≤21 units (men) and ≤14 units (women) per

week.

• Regular physical exercise– Aerobic type of exercise e.g. brisk walking for 30-

60 minutes at least 3 times a week.

Lifestyle Modification

• Healthy eating– Diet rich in fruits, vegetables and dairy products

with reduced saturated and total fat can lower BP– BP 11/6 mmHg in hypertensive patients

JNC 7 Treatment RecommendationsInitial Drug Therapy

JNC 7 Express. NIH publication No 03-5233. http://www.nhlbi.nih.gov/guidelines/hypertension/express.pdf. May, 2003.

Algorithm for Treatment of HTN

Compelling Indications

Diuretic B-Blocker ACE Inhibitor

ARB CCB Aldosterone antagonisst

Heart Failure X X X X X

Post-MI X X X

High CAD risk

X X X XNon-DHP

Diabetes X X X X XNon-DHP

Chronic renal disease

X X

2° Stroke prevention

X X

NHBPEP Coordinating Committee. The JNC 7 Report. JAMA 2003;289:2560-72.

Types of Antihypertensive Drugs1) ACE-i

- in patient with increased cardiovascular risk, ACE-I to reduce morbidity and mortality- prevent onset of microalbuminuria, reduce protenuria, and progression of renal disease- side effect: cough and angioedema.- serum creatinine should be checked before initiation and repeated after one or two weeks after initiation.

ACE- InhibitorACEi Starting daily dose Maximum daily dose

captopril 25mg bd 50 mg tds

enalapril 2.5mg od 20 mg bd

fosinopril 10mg od 40 mg od

lisinopril 5mg od 80 mg od

• 2) Angiotensin Receptor Blocker- Recommended in ACEi intolerance patient- Preventing progression of diabetic

retinopathy, and reduce major cardiac events.- Less side effect of dry cough

ARBARBs Starting dose Maximum daily dose

Candesartan 8 mg od 16 mg od

Irbesartan 150mg od 300 mg od

losartan 50 mg od 100 mg od

Valsartan 80 mg od 100 mg od

telmisartan 20 mg od 160 mg od

3) Beta blocker- Useful in hypertensive patient with angina,

tachyarrhytmia, or previous myocardial infarction

- Contraindicated in obstructive airway disease, severe peripheral vascular disease and heart block.

- Side effect: dyslipidemia, hypoglycemia, increase incidence of new onset of DM, erectile dysfunction and cold extremities.

• Beta blockersB Blockers Starting dose Maximum daily dose

acebutolol 200mg bd 400mg bd

atenolol 50 mg od 100mg od

betaxolol 10 mg od 40mg od

bisoprolol 5mg od 200mg bd

metoprolol 50 mg bd 200 mg bd

propanolol 40 mg bd 320 mg bd

4) Calcium channel blocker- Use as first line treatment and other

combination with other drug- No undesirable adverse metabolic effect - Adverse effect: initial tachycardia, headache,

flushing, constipation and ankle edema

• CCB CCBs Starting dose Maximum daily dose

Amilodipine 5mg od 10 mg od

Diltiazem 30mg tds 60 mg tds

felodipine 2.5mg od 10 mg od

nifedipine 10 mg tds 30mg tds

verapamil 80 mg bd 240mg tds

Verapamil CR 200mg od 200 mg bd

• 5) Diuretics

- most widely used antihypertensive agents- Patient with essential hypertension and normal renal

function, thiazide are more potent than loop diuretics- Patient with renal insufficiency, thiazide are less

effective, and loop diuretics are to be used instead.- Potassium sparing diuretics may cause hyperkalemia if

given together with ACEi or ARBs- Side effets: increased serum cholesterol, glucose and

uric acid. Decreased potassium, sodium and magnesium level

DIURETICSdiuretics Starting dose Maximum dose daily

chlorothiazide 250 mg od 500mg od

hydrocholorothiazide 25mg od 200mg od

Amiloride 5g/ 50 mg 1 table t od 4 tablet od

indaparamide 2.5 mg od 2.5 mg od

Triamterene 50 mg/ 25 mg 1 tablet bd 2 tablet bd

In ED

• HPT Emergency• HPT Urgency

HYPERTENSIVE EMERGENCY• Severe elevation in BP (usually >180/120) complicated

by evidence of progressive target organ dysfunction• Target organ dysfunction includes:

I. Hypertensive encephalopathyII. Hypertensive Lt ventricular failure(acute pulmonary

edema)III. Acute aortic dissectionIV. ACS / Acute MIV. Haemorrhagic / Ischaemic Stroke / SAHVI. Acute renal failureVII. Eclampsia

JNC 7

HYPERTENSIVE URGENCY

• Situations associated with severe elevation in BP without progressive target organ dysfunction

JNC 7

Is it HPT emergency or urgency?• History• Is the BP measurement correct?• Any evidence of end organ damage?• Physical examination:

– Fundoscopy– Neurological examinations– Cardiovascular examinations

• Bedside ix– ECG– Urine dipstick-proteinuria– UPT in woman of child bearing age

• Lab ix : FBC, BUSE/CREAT, CE accordingly• Radiology

– CXR – CT brain

Management

• Hypertensive emergency– BP to be reduced by 25% over 3 to 12 hours but

not lower than 160/90 mmHg– best achieved with parenteral drugs

HYPERTENSIVE EMERGENCIESDRUGS DOSE ONSET OF

ACTIONDURATION REMARKS

Sodium nitroprusside

0.25-10 μg/kg/min Sec. 1-5min Caution in renal failure

Labetalol IV bolus 50mg (over at least 1 minute) at 5 min intervals to max of 200mg then 2mg/min IVI

<5min 3-6hrs Caution in heart failure

Nitrates 5-100μ/min 2-5min 3-5min Prefferred in ACS and acute pulmonary edema

DRUGS DOSE ONSET OF ACTION

DURATION REMARKS

Hydralazine IV 5-10mg maybe repeated after 20-30min of IVI 200-300μg/min.Maintenance 50-150μg/min

10-20min 3-8hrs Caution in ACS, CVA and dissecting aneurysm

Nicardipine IV bolus 10-30μg/kg over 1min IVI 2-10μg/kg/min

5-10min 1-4 hrs Caution in heart failure and coronary ischaemia

Esmolol IV bolus 1-2min, 250-500 μg/kg over I min.IVI 50-200μg/kg/min for 4 min. May repeat sequence

3-10min Used in perioperative situations and tachyarrythmia

Management

• Hypertensive urgency– aim for about 25% reduction in BP over 24 hours

but not lower than 160/90 mmHg– Oral drugs proven to be effective

HYPERTENSIVE URGENCY

DRUG DOSE ONSET OF ACTION

DURATION FREQUENCY

Captopril 25mg ½ hour 6 hour 1-2 hours

Nifedipine 10-20mg ½ hour 3-5 hour 1-2 hours

Labetalol 200-400mg 2 hours 6 hour 4 hours

Disposition

• HPT emergency– Admit to ICU in consultation with general

medicine and respective subspecialities• HPT urgency

– Can be discharge if response is prompt and BP acceptable after 4hours monitoring, but must arrange for follow up within 48 hours

– Newly diagnosed HPT with uncertain cause, admit for further evaluation and exclusion of 2ry causes

REFERRENCE

• JNC 7• CPG on HPT• Guide to essentials in emergency medicine-

Shirley Ooi