| ID | 78 |
|---|---|
| Name | SYSTEMIC HYPERTENSION |
| Cause | |
| Signs Symptoms | |
| Diagnosis | Diagnosis: A. History - 1. There may be familial history of hypertension. 2. History of table salt intake. 3. History of smoking. 4. History of analgesic & steroid intake. 5. Obese person. 6. Hyperlipidaemia i.e. Xanthoma, Arcus lipidus. B. Investigation - 1. Urine- albumin, glucose pus cells & R.B.C. 2. Blood urea, creatinine & electrolyte- blood urea may be high & serum potassium may be low. 3. Serum cholesterol (including HDL, LDL) & triglycerides. 4. X-ray chest- for cardiomegaly, heart failure & coarctation of aorta. 5. E.C.G- any ischaemic change or sign of left ventricular hypertrophy. C. Special investigations for selective patients- 1. Echocardiogram- to detect left ventricular hypertrophy. 2. Renal ultrasonogram- to detect any renal disorder. |
| Investigations | |
| Management | Management:1-2 A. General management: Non-drug treatment or life style measures: All patients with high-normal or elevated blood pressure, those who have a family history of cardiovascular complications of hypertension, and those who have multiple coronary risk factors should be advised for non-drug treatment or life style modification to lowering blood pressure (< 140/90 mm Hg). 1. Diet: i. Weight reduction in obese and overweight patients. ii. Eating oily fish and vegetable oil, and avoiding animal fat (i.e adopting & diet low in saturated fat). iii. Moderate sodium restriction (70-80mmol/l) is helpful- this can be achieved by not adding excess salt to food and avoiding foods with high salt content, iv Aviod alcohol. v. Increasing consumption of fruit and vegetables. 2 Exercise: Regular exercise programme improves physical fitness & lowers blood pressure. 3. Smoking: Stop smoking. 4. Hyperlipidaemia: Test for serum cholesterol (including HDL, LDL) & triglycerides & take measure accodringly. Patients with high-normal or prehypertensive blood pressure should not be treated with antihypertensive drugs. But, if there is compelling indications) such as diabetes, cardiovascular disease or chronic kidney disease, the threshold for initiating antihypertensive therapy is lower (i.e 140/90 mm Hg) Treatment by drugs:1,2,3 Stepwise management of hypertension: British hypertension society (BUS) guidelines: The BUS guidelines recommended antihypertensive regimen as the “ABCD “ rule, where ‘A’ for ACE inhibitors (angiotensin-converting enzyme inhibitor) or ARB (angiotensin II receptor blacker); ‘B ‘for b-blockers; ‘C ‘for calcium channel blockers; ‘D’ for diuretic (thiazide). In this ADCD rule, drugs are considered into two complementary groups- AB & CD. A and B refer to drugs that interrupt the renin-angiotensin system (ACE/ARB & p-blockers); C and D refer to those drugs that do not interrupt the renin-angiotensin system (calcium channel blockers and thiazide diuretics). AB drugs are more effective in young, white persons, and in whom renins tend to be higher; CD drugs are more effective in old, black persons, and in whom renin levels are generally lower.’ Step 1: Mild hypertension: a. Patient younger than 55 years- A (or B) b. Patient aged 55 years or older- C (or D) In the group of patients younger than 55 years, treatment should be started with A (ACE inhibitor or ARB if patient is intolerant of ACE inhibitor) or with B (b-blocker, in patients associated with ischaemic heart disease, gout and mild maturity onset diabetes). Now a day b-blockers are not considered as the ideal first-line agents for antihypertensive therapy. In the group of patients aged 55 years or older, treatment should be started with C (calcium channel blockers) or with D (thiazide diuretics, in older hypertensive patients with mild heart failure, asthma and brittle diabetes on insulin). Step 2: Moderate hypertension: A (or B) + C or D. In moderate hypertension combination of two drugs is advisable. In this case, combination of drugs between AB and CD groups are more effective in lowering blood pressure than combination within a group. Step 3:. Severe hypertension: A (or B) + C + D. In severe hypertension combination of three drugs is advisable. In this combination an ACE inhibitor (or an ARB if patient is intolerant of ACE inhibitor), a calcium channel blocker (vasodilator), and a thiazide diuretic are given. In case of CCF, vasodilator is used in initial treatment. Step 4: Resistant hypertension: A (or B) + C + D + a-blocker or spironolactone or other diuretic. In resistant hypertension an additional drug (an a-blocker or spironolactone or other diuretic) is given with the combination of step-3 drugs. Antihypertensive drugs: 1. ACE inhibitors;!,2,21,22,23 Angiotensin converting enzyme (ACE) inhibitors inc\ude-Captpril,Cilazapril, Enalapril, Fosinopril, Imidapril, Lisinopril, Moexipril, Perindopril, Quinapril, Ramipril and Trandolapril. ACE inhibitors inhibit the conversion of angiotensin I to angiotensin. II. They are effective and generally well tolerated. Dosage: Enalapril 20mg daily; Ramipril 5-10mg daily; or Lisinopril 10-40mg daily. 2. Angiotensin II receptor blockers (ARB):1-2-21,6-54 Angiotensin II receptor blockers (ARB) include- Candesartan, Irbesartan, Losartan, Olmesartan, Telmisartan, and Valsartan. ARB drugs act by blocking the action of angiotensin-II on the heart, peripheral vasculature and kidney. Angiotensin-II is a potent vasoconstrictor, the primary vasoactive hormone of the renin-angiotensin system and an important component in the pathophysiology of hypertension. The angiotensin-II receptor blockers block the vasoconstrictor and aldosterone secreting effects of angiotensin-II by selectively blocking the binding of angiotensin-II. ARB drugs have many properties & effects similar to those of the ACE inhibitors. Dosage: Candesartan 8mg to 32mg once daily or divided in two daily doses; Irbesartan 150-300mg daily; Valsartan 40-160mg daily. 3. B-adrenergic blocking agents (B-blockers):1-2-21-52 b-blockers include- Propranolol, Acebutolol, Bisoprolol, Carvedilol, Celiprolol, Esmolol, Labetalol, Metoprolol, Nadolol, Nebivolol, Oxprenolol, Pindolol, Sotalol & Timolol. b- blockers act by bloking the b- adrenoceptor in the heart, peripheral vasculature, bronchi, pancreas & liver. In the heart b-blockers block the action of noradrenaline & adrenaline on P-receptors & controls its rate and rhythm of beating & force of muscle contraction. Thus, these reduce the need of heart muscle for oxyzen demand. Therefore, b-blockers are useful in the treatment of hypertension & angina. b-blockers also decrease renin release and are more efficacious in populations with elevated plasma renin activity, such as younger white patients. b-blockers were used as the first-line antihypertensive drugs for long time, but now a day these are not considered as the ideal first-line agents except in patients with another indication for the drug e.g angina. Labetalol and carvedilol are combined b-and a-adrenoceptor antagonists which are sometimes more effective than pure p-blockers. Dosage: Atenolol 50-100mg daily once or two divided doses; Bisoprolol 5-10mg daily; Metoprolol 100-200mg once daily; Carvedilol 6.25-25mg 12 hourly; Labetalol 200mg-2.4gm daily in divided doses. 4. Calcium channel blockers (COB): 2-42-4-52 Calcium channel blockers include- Amlodipine, Diltiazem, Felodipine, Isradipine, Lacidipine, Lercanidipine, Nicardipine, Nifedipine, Nimodipine, Nisoldipine, Verapamil. Calcium channel blockers reduce hypertension by peripheral vasodilation and relieve angina by reducing cardiac muscle activity. They inhibit the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. The contractile process of cardiac muscle and vascular smooth muscle is dependent upon the movement of extracellular calcium ions into these cells through specific ion channels. CCBs inhibit calcium ion influx across cell membranes selectively, with a greater effect on vascular smooth muscle cells than on cardiac muscle cells. These act directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure. Therefore, calcium channel blockers are more effective in hypertension with ischaemic heart disease particularly in olders. Dosage: Amlodipine 5-10mg daily once or in two divided doses; Nifedine 10-30mg thrice daily; Diltiazem 200-300mg daily, Verapamil 240mg daily. 5. Diuretics including Aldosterone receptor antagonists:1-2-21-26-33-46-53-105 Diuretics include: Thiazide diuretics e.g Bendrofluazide, Chlorthalidone, Cyclopenthiazide, Hydrochlorothiazide, Indapamide; Loop-acting diuretics, such as- Frusemide, Bumetanide, Torasemide; Aldosterone antagonists & Potassium-sparing diuretics e.g Spironolactone, Amiloride, Eplerenone. Diuretics act as antihypertensive by decreasing plasma volume and cardiac output by suppressing tubular reabsorption of sodium, as a result incrasing excretion of sodium and water. They also cause reduction of peripheral vascular resistance when used for long time. Dosage: Thiazide diuretics: Bendrofluazide 2.5mg once daily; Chlorthalidone 25mg as a single daily dose, may be increased upto 50-100mg daily; Cyclopenthiazide 0.5mg once daily; Hydrochlorothiazide 50-100mg daily as a single dose or divided doses, maximum 200mg daily; Indapamide 2.5mg daily as a single dose. Loop-acting diuretics: Frusemide 40mg daily; Bumetanide Img daily; Torasemide 2.5mg once daily, may be increased to 5mg once daily. Potassium-sparing diuretics: Spironolactone 100mg daily, may be increased to 400mg daily, maintenance 75-200mg daily. 6. a-Adrenoceptor Antagonists (arBlockers):1-21-26-33-49 a-Blockers include: Prazosin, Doxazosin, Indoramin, Terazosin. a-Adrenoceptor blocking drugs block post synaptic ct-receptors, relax smooth” muscle and therefore, vasodilatation, as a result lowering peripheral vascular resistance and reduction of blood pressure. These drugs however, cause a rapid reduction in blood pressure after the first dose and should be introduced with caution, a-blockers may be used with other antihypertensive drugs in the treatment of severe hypertension. Dosage: Prazosin 0.5mg on first evening, then 0.5mg 2 or 3 times daily for 3-7 days followed by Img 2 or 3 times daily for 3-7 days; there after, increase gradually as required, maximum 20mg daily. Terazosin Img initially at bedtime, dose can be increased or doubled after 7 days if necessary; maintenance dose 2-10mg once daily. 7. Other drugs:1-3 Some drugs that directly act on vascular smooth muscle and cause peripheral vasodilation, such as hydralazine & minoxidil. They are usually given in conbination in resistant hypertension because, when given alone, they cause reflex tachycardia, palpitations, headache, increased myocardial contractility and fluid retention. Besides, hydralazine produces frequent gastrointestinal disturbances and may induce a lupus-like syndrome; minoxidil causes increased facial hair (hirsutism) and therefore not suitable for female patients. Centrally acting antihypertensives, such as methyldopa, clonidine, moxonidine are now seldom used. But, recently moxonidine is useful when ACE inhibitors have failed, as it has very little side-effects rather than first generation drugs i.e a-methyl dopa & clonidine. Management of hypertensive emergencies & malignant hypertension: Hypertensive emergencies include- i. hypertensive encephalopathy, ii. hypertensive nephropathy, iii. intracranial haemorrhage, iv. preeclampsia-eclampsia v. pulmonary oedema, vi. unstable angina or, vii. myocardial infarction etc. Malignant hypertension is characterized by encephalopathy or nephropathy with accompanying papilloedema. Progressive renal failure usually develops if treatment is not given in time. The therapeutic approach in both cases is identical. A. Parenteral therapy: Indicated in most hypertensive emergencies specially if encephalopathy is present- Inj. Sodium nitrprusside 0.3-1.0mg/kg/min. by i.v infusion. (This is most effective agent, and lowers the blood pressure within seconds by direct arteriolar and venous dilatation). Or, Inj. Labetalol 2mg/min to a maximum of 200mg i.v or i.m. (It is a combined b-and a-adrenergic blocking agent and is very much potent in rapid lowering of pressure). Or, Inj. Hydralazine 5 or 10mg i.v or i.m, repeated at half-hourly intervals & adjusted as the blood pressure response. (But, it produces reflex tachycardia and palpitations, so, it should not be given without b-blocker in patients with possible coronary disease). The above all measures are effective in controlling hypertensive emergencies but, requires very careful supervision, preferably in an I.C.U. B. Oral therapy: Some patients with less severe acute hypertensive syndromes can often be treated with oral therapy- Clonidine 0.2mg orally initially, followed by 0. Img every hour to a total of 0.5mg, (will usually lower blood pressure over a period of several hours. Sedation is frequent, and rebound hypertension may occur if the drug is stopped). Or, Nifedipine 10mg capsule chewing, often sufficient to produce a graded reduction in blood presure. Or, Captopril 12.5-25mg orally, will also lower blood pressure in 15-30 minutes. C Subsequent management: When the blood pressure has been brought under control- i. Combinations of oral antihypertensive agents can be added as parenteral drugs are tapered off over a period of 2-3 days. ii. The subsequent regimens should include a diuretic. iii. Bed-rest, and a sedative may also be given. iv. Urinary output and plasma electrolytes should be monitored. v. Immediate enquiry in finding out underlying cause. Guideline for treatment of hypertension in different situations: Hypertension in Pregnancy: 1. BP < 140/90 mmHg- no treatment. 2. BP >140/90 to 150/100 mmHg- treatment required. In case of hypertension in pregnancy, if the patient is under medical supervision or in the hospital, following measures should be taken stepwise- i. Bed rest ii. Anxiolytic drug iii. Antihypertensive drug- methyldopa or labetalol iv. Vasodilator v. Delivery - if foetus is viable. In pregnancy, methyldopa (& also labetalol) has been found a safe antihypertensive. Mild hypertension can be treated with methyldopa, with a dose upto 3gm/day. Pre-eclamptic hypertension also can be treated with methyldopa or nifedipine; but in case of overt pre-eclampsia delivery is the only method for reversal. In case of more severe hypertension or eclampsia, treatment should be given with i.v hydralazine and termination of pregnancy may also be required. Hypertension in Elderly: 1. Thiazide alone, 1st choice. 2. Where combined preparation is needed, thiazide diuretics and dihydropyridine calcium channel blockers (amlodipine, nifedipine) are the most suitable drugs for the treatment of high BP in older people. Hypertension with Diabetes: 1. Methyldopa. 2. Vasodilator. 3. Thiazide when used insulin dose to be increased. 4. b-blocker avoided in brittle diabetes. Hypertension after a stroke: If diastolic blood pressure still above 105 mmHg, treatment should be given by less agressive drugs. Drugs which cause postural hypotension should be avoided. Hypertension and Heart failure: 1. Thiazide or frusemide. 2. Methyldopa. 3. Prazosin or isosorbide dinitrate. Hypertension with Angina: b-blocker and/or calcium channel blocker due to their antihypertensive and anti-anginal effect. Hypertension with obstructed airway disease: 1. Thiazide. 2. Thiazide + Methyldopa. 3. b-blocker is contraindicated. Hypertension and Depression: 1. Diuretics 2. b-blocker 3. Basodilator 4. Depressive drugs avoided Hypertension and Renal failure: 1. Salt restriction upto 100 mmol/day. 2. Frusemide as required daily. 3. b-blocker 3. Dialysis |
| Introduction | Systemic blood pressure of an individual or a group of population has no definite range or level to be defined as normal, and hence any rise or deviation from that range can be considered as hypertension. Because, blood pressure is a characteristic of each individual & it varies with age, sex & ethnic background. Considering all these factors, many authorities recommended some guidelines to define normal levels of blood pressure and that of hypertension for different age group of population. On the basis of that guidelines, hypertension thus defined as a ‘persistent rise of blood pressure above the generally accepted arbitrary ‘normal’ levels for specific age groups, such as systolic blood pressure above 140 mm Hg and/or diastolic blood pressure above 90 mm Hg at the age of 20. Generally accepted upper normal levels of blood pressure for specific age groups: Age Pressure 20 years 140/90 mm of Hg. 50 years 160/95 mm of Hg. 75 years 170/105 mm of Hg. Degree of hypertension: Adults aged 18 years or older1-2 BP Category Diastolic B.P mm Hg Systolic B.P mm Hg Optimal <80 <120 Normal 85 <130 Prehypertension 80-89 130-139 (High normal) Hypertension Grade -1 (mild) 90-99 140-159 Grade -2 (moderate) 100-109 160-179 Grade -3 (severe) 110 or more 180 or more |
| History | |
| Etiology | Etiology: A. Essential or idiopathic or primary hypertention (90-95%.) Factors influence- i. Genetic & familial cause. ii. Socioeconomic- related to social deprivation. iii. Dietary factors- obesty, high salt intake, high alcohol, caffeine. iv Hormonal factors- e.g high renin. v. Neurotransmitters- e.g acetylcholine, noradrenaline. B Secondary to other diseases, like- i. Coarctation of the aorta. ii. Renal diseases i.e. chronic glomerulonephritis, chronic pyelonephritis, renal artery stenosis, polycystic kidney disease. iii Endocrine disorders- i.e. phaeochromocytoma, cushing’s syndrome, conn’s syndrome. iv Alcohol. v. Drugs, like- oral contraceptives, anabolic steroid, corticosteroids, NSAIDs. vi. Pregnancy. |
| Clinical Features | Clinical features: Symptoms: May be asymptomatic; diagnosis is usually made during routine examination. A. Symptoms due to simple rise of blood pressure- Occpital headache, particularly in the morning, palpitation, dizziness, tiredness, insomnia. B. Symptoms due to etiology-Such as, recurrent backache, undiagnosed fever, polyurea, polydipsia, (as in renal diseases). Muscle weakness due to hypokalaemia (as in aldosteronism). Weight gain, abdominal disturbance (as in cushing syndrome). Panic attacks, paroxysmal headache, palpitation (as in phaeochromocytoma). C. Symptoms due to complications- Heart failure- PND, orthopnia, respiratory distress. Cerebral haemorrhage or ischaemia- stroke, TIA. Encephalopathy- slurred speech, paraesthesia, fits. Features of ischaeima- angina. Features of renal failure- anuria. Epistaxis, haematuria, blurring of vision due to vascular involvement. Signs: B.P- raised. There may be no other signs. Apex beat- displaced, forceful & may be sustained (as in LVH). Loud 2nd heart sound, early diastolic murmur. Renal angle tenderness, kidney may be palpable, bruit over renal artery may be present. Radial-femoral delayed pulse, arterial pulsation in neck and low B.P in lower limb may be present (as in coarctation of Aorta). Fundoscopic examination- decreased tortuosity of retinal artery, arteriovenous nipping, flame shaped haemorrhage and papilloedema may be present. |
| Preventions | |
| Treatment | |
| Complications | Complications: 1. Cerebral- haemorhage, thrombosis, hypertensive encephalopathy. 2. Cardiac- left ventricular hypertrophy & failure. 3. Ocular-hypertensive retinopathy. 4. Renal- renal failure. |
| Prognosis | |
| Types | |
| Classification | |
| Observation | |
| Pathology |
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