Management of hypertension and hypertensive emergencies.pptx

Managemement of hypertension and hypertensive emergencies.

1. MANAGEMENT OF HYPERTENSION AND HYPERTENSIVE EMERGENCIES PRESENTERS : Luyimbazi Ivan Omaido Blair Andrew Tutor: Dr. Nabunnya Y. Wednesday, April 22, 2015 1

2. Definition Uncontrolled HTN is defined as systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg. Isolated systolic HTN (ISH) is defined as SBP ≥140 mm Hg and DBP <90 mm Hg, isolated diastolic HTN (IDH) is defined as SBP <140 mm Hg and DBP ≥90 mm Hg, and systolic-diastolic HTN (SDH) is defined as SBP ≥140 mm Hg and DBP ≥90 mm Hg Wednesday, April 22, 2015 2

3. Epidemiology Uncontrolled Hypertension in Uganda: A Comparative Cross-Sectional Study by Geofrey Musinguzi et al, 2014 in 2 districts among 15yr olds and above showed a prevalence of uncontrolled hypertension was 20.2% . The middle aged and older groups had a higher prevalence than the younger subjects(15-34) The prevalence of normal blood pressure was 37.6%, pre-hypertension 33.9%, hypertension 28.5% and raised blood pressure 62% among 18yr olds and above: Nuwaha and Musinguzi , 2013 Wednesday, April 22, 2015 3

4. Classification Based on recommendations of the JNC 7, the classification of BP (expressed in mm Hg) for adults aged 18 years or older is as follows Normal: Systolic lower than 120 mm Hg, diastolic lower than 80 mm Hg Prehypertension: Systolic 120-139 mm Hg, diastolic 80-89 mm Hg Stage 1: Systolic 140-159 mm Hg, diastolic 90-99 mm Hg Stage 2: Systolic 160 mm Hg or greater, diastolic 100 mm Hg or greater Wednesday, April 22, 2015 4

5. JNC 8 RECOMMENDATIONS SUMMARY G eneral population aged ≥60 years, SBP≥150 mm Hg or DBP ≥90 mm Hg and treat to a goal SBP <150 mm Hg and goal DBP <90 mm Hg General population <60 years, DBP ≥90 mm Hg or SBP ≥140mmHg and treat to a goal DBP <90 mm Hg or SBP <140mmHg General population aged ≥18 years with chronic kidney disease (CKD ), SBP ≥ 140mmHg or DBP ≥ 90 mmHg and treat to goal SBP<140mmHg and goal DBP<90 mmHg In the population aged ≥ 18 years with diabetes, SBP ≥ 140mmHg or DBP ≥ 90mmHg and treat to a goal SBP <140 mm Hg and goal DBP <85 mm Hg Wednesday, April 22, 2015 5

6. RECOMMENDATIONS……… In the general black population, including those with diabetes, initial antihypertensive treatment should include a thiazide-type diuretic or CCB. In the population aged ≥18 years with CKD, initial (or add-on) antihypertensive Rx should include an ACEI or ARB to improve kidney outcomes. This applies to all CKD patients with hypertension regardless of race or diabetes status. The main objective of hypertension Rx is to attain and maintain goal BP . If goal BP is not reached within a month of Rx, increase the dose of the initial drug or add a second drug from one of the classes (thiazides, CCB, ACEI, or ARB) Wednesday, April 22, 2015 6

7. Cont.. the JNC 8 recommends treating to 150/90 mm Hg in patients over age 60 years; for everybody else, the goal BP is 140/90 resistant hypertension: hypertension in which BP is >140/90 mm Hg despite the use of medications from 3 or more drug classes, 1 of which is a thiazide diuretic Wednesday, April 22, 2015 7

8. Cont.. Hypertension may be primary, which may develop as a result of environmental or genetic causes secondary, which has multiple etiologies, including renal, vascular, and endocrine causes. Primary or essential hypertension accounts for 90-95% of adult cases, and secondary hypertension accounts for 2-10% of cases Wednesday, April 22, 2015 8

9. HTN crises Hypertensive crises: a BP of more than 180/120 mm Hg and may be further categorized as hypertensive emergencies or urgencies. Hypertensive emergencies are characterized by evidence of impending or progressive target organ dysfunction hypertensive urgencies are those situations without progressive target organ dysfunction. Wednesday, April 22, 2015 9

10. Htn emergency The most common hypertensive emergency is a rapid unexplained rise in BP in a patient with chronic essential hypertension. Most patients who develop hypertensive emergencies have a history of inadequate hypertensive treatment or an abrupt discontinuation of their medications Wednesday, April 22, 2015 10

11. Cont.. In hypertensive emergencies, the BP should be aggressively lowered within minutes to an hour by no more than 25%, and then lowered to 160/100-110 mm Hg within the next 2-6 hours Acute end-organ damage in hypertensive emergency include: Neurologic, Cardiovascular, retinal, renal. Wednesday, April 22, 2015 11

12. Cont.. Neurologic: hypertensive encephalopathy, intracranial hemorrhage Cardiovascular: myocardial ischemia/infarction, acute left ventricular dysfunction, acute pulmonary edema, aortic dissection, unstable angina pectoris Other: acute renal failure/insufficiency, retinopathy, eclampsia, microangiopathic hemolytic anemia Wednesday, April 22, 2015 12

13. Risk factors of htn non modifiable – Ethnic-genetic risk (black people) – Age – Gender - family hx modifiable – Diabetes – Overweight – Alcohol – Salt intake -Physical inactivity,sedentary lifestyle -stress -cigarette smoking Wednesday, April 22, 2015 13

14. Pathophysiology of HTN Multifactorial Bp determined by humoral mediators, vascular reactivity, circulating blood volume, vascular caliber, blood viscosity, cardiac output, blood vessel elasticity, and neural stimulation HTN mayb due to genetic predisposition, excess dietary salt intake, and adrenergic tone Wednesday, April 22, 2015 14

15. Pathophysiology of Hypertension cardiac output x Peripheral resistance = Blood pressure Heart Rate Stroke volume x Wednesday, April 22, 2015 15

16. Pathophysiology of Hypertension The role of endothelium and the RAAS cascade Angiotensinogene Angiotensin I Angiotensin II receptor Renin ACE AT1 AT2 prorenine, catecholamines Pathway of RAAS in the Organism (kidney, heart, Vessels) to maintain Fluid volume control, Adjustment of CO and Resistance. If regulation fails, high blood pressure occurs Pathway of RAAS in the Tissues: e.g. Vessel wall Competition of receptors: AT1 vasoconstriction AT2 vasodilatation Wednesday, April 22, 2015 16

17. AT 1 AT 2 AT 1 stimulation leads to: growth+ vasoconstriction AT 2 stimulation leads to: differentiation vasodilatation vasoactivity Smooth muscle cell growth Angiotensin II Actions on endothelium and NO =nitric oxide modified acc. to Unger T et al 1996 NO NO inhibition Wednesday, April 22, 2015 17

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19. Pathophysiology of Hypertension: secondary H. Renal 2.5-6% Parenchymal..polycystic kidney disease Renovascular Tumors,renin producing Liddle syndrome Endocrine Thyroid dysfunction (1%) Adrenal (0,3%) Carcinoid Hormones, oral contraceptives, Pheochromocytoma,cushing syndrome,primary aldosteronism Aortic coarctation Pregnancy Neurogenic (brain tumor, lead, porphyria, sleep apnea) Acute stress (including surgery) iv. volume increase Drugs and toxins –Alcohol,cocaine Some may induce primary hypertension, so that the relationships sometimes are weak Wednesday, April 22, 2015 19

20. Clinical features Referred to as the “silent killer” Frequently asymptomatic until target organ disease occurs Or recognized on routine screening Wednesday, April 22, 2015 20

21. Clinical features Sx often secondary to target organ disease Can include: Fatigue, reduced activity tolerance Dizziness Palpitations, angina Dyspnea Wednesday, April 22, 2015 21

22. HTN complications Target organ diseases occur most frequently in: Heart Brain Peripheral vasculature Kidney Eyes Wednesday, April 22, 2015 22

23. Complications… Hypertensive heart disease Coronary artery disease Left ventricular hypertrophy Heart failure Cerebrovascular disease Stroke Peripheral vascular disease Nephrosclerosis Retinal damage Wednesday, April 22, 2015 23

24. Complications… Atherosclerosis most common cause of cerebrovascular disease; hypertension major risk factor for cerebral atherosclerosis and stroke Atherosclerosis in peripheral blood vessels too; can lead to PVD, aortic aneurysm, aortic dissection Hypertension one of leading causes of end-stage renal disease, esp. in African-Americans; some degree of renal dysfunction usual in person with even mild BP elevations Retina is only place blood vessels can be directly visualized; if see damage there then indicates damage in brain, heart, & kidney too; Can cause blurring, retinal hemorrhage and blindness Wednesday, April 22, 2015 24

25. Dx History and physical examination BP measurement in both arms Use arm with higher reading for subsequent measurements BP highest in early morning , lowest at night In the absence of end-organ damage -mild hypertension dx made after two visits, two weeks apart Wednesday, April 22, 2015 25

26. Office bp measurement Use auscultatory method with a properly calibrated instrument Patient seated quietly for 5 min in a chair, feet on the floor, and arm supported at heart level Appropriate-sized cuff is necessary to ensure accurate reading At least two measurements should be obtained Allow at least 1 minute between readings. If one arm higher than other; take BP in higher arm for subsequent measurements Wednesday, April 22, 2015 26

27. Investigations Cbc for hct Urinalysis Rft Lipid profile for total and hdl-cholesterol,triglycerides ECG + ECHO Thyroid function tests Renin levels Vinyl mandelic acid Radiographic imaging Wednesday, April 22, 2015 27

28. MANAGEMENT The objective of treatment is to reduce risk of complications & improve survival Benefits to be weighed against side effects & inconvenience. So it is important to treat the patient as a whole not just blood pressure. Treatment involves pharmacotherapy and lifestyle modification measures. Wednesday, April 22, 2015 28

29. MANAGEMENT Who should be treated?  —  In the absence of end-organ damage, a patient should not be labelled as having hypertension unless: the blood pressure is persistently elevated after two visits, two weeks apart . All patients should undergo appropriate nonpharmacologic ( lifestyle modification ). Antihypertensive medications should generally be begun if the systolic pressure is persistently ≥140 mmHg and/or the diastolic pressure is persistently ≥90 mmHg despite attempted nonpharmacologic therapy Starting with two drugs should be considered in patients with a baseline BP > 160/100 mmHg. Wednesday, April 22, 2015 29

30. LIFESTYLE MODIFICATIONS Modification Recommendation App. SBP reduction range Weight reduction Maintain normal body weight (BMI, 18.5 to 24.9 kg/m2) 5-20 mmHg per 10-kg weight loss Adopt DASH eating plan Consume a diet rich in fruits, vegetables, and low-fat dairy products with a reduced content of saturated and total fat 8 to 14 mmHg Dietary sodium reduction Reduce dietary sodium intake to no more than 100 mg/day (2.4 g sodium or 6 g sodium chloride) 2 to 8 mmHg Physical activity Engage in regular aerobic physical activity such as brisk walking (at least 30 minutes per day, most days of the week) 4 to 9 mmHg Moderation of alcohol consumption Limit consumption to no more than 2 drinks per day in most men and no more than 1 drink per day in women and lighter-weight persons 2 to 4 mmHg Wednesday, April 22, 2015 30

31. Lifestyle modification Cont’d Patient education — Patient education has been demonstrated to result in improved blood pressure control . In addition to education of patients by their clinicians, blood pressure control may be improved when patients with hypertension hear the personal stories of their peers with hypertension. Other — adequate potassium intake, cessation of smoking, and limiting the use of nonsteroidal antiinflammatory drugs. Wednesday, April 22, 2015 31

32. Blood pressure goals in hypertensive patients SBP, systolic blood pressure; CV, cardiovascular; TIA, transient ischaemic attack; CHD, coronary heart disease; CKD, chronic kidney disease; DBP, diastolic blood pressure. Recommendations SBP goal for “most” Patients at low–moderate CV risk Patients with diabetes Consider with previous stroke or TIA Consider with CHD Consider with diabetic or non-diabetic CKD <140 mmHg SBP goal for elderly Ages <80 years Initial SBP ≥160 mmHg 140-150 mmHg SBP goal for fit elderly Aged <80 years <140 mmHg SBP goal for elderly >80 years with SBP ≥160 mmHg 140-150 mmHg DBP goal for “most” <90 mmHg DB goal for patients with diabetes <85 mmHg

33. DRUG TREATMENT General efficacy — the amount of blood pressure reduction is the major determinant of reduction in cardiovascular risk in patients with hypertension, not the choice of antihypertensive drug Initial monotherapy in uncomplicated hypertension — In the absence of a specific indication: thiazide diuretics, long-acting calcium channel blockers (most often a dihydropyridine such as amlodipine), and ACE inhibitors or angiotensin II receptor blockers. Beta blockers not commonly Combination therapy — Single agent therapy may not adequately control the blood pressure, particularly in those whose blood pressure is more than 20/10 mmHg above goal. Has greater blood pressure lowering effect than doubling the dose of a single agent (long-acting ACE I or angiotensin receptor blocker in concert with a long-acting dihydropyridine calcium channel blocker. Goal blood pressure for uncomplicated HTN: <140/90 mmHg Wednesday, April 22, 2015 33

34. DRUG TREATMENT DRUG DOSE TOXICITIES Thiazide diuretics Hydrochlorothiazide Chlorthalidone 12.5-50mg P.o od 25-100 mg/day p.o. Hypokalemia , hyperglycemia , hyperuricemia , hyperlipidemia Loop diuretic: Torsemide 2.5-5mg/day initially increased to 10mg/day po in 4-6 weeks Hypokalemia , hypovolemia, ototoxicity ACEI Captopril Lisinopril Ramipril Captopril 25mg 2-3 times a day Lisinopril 10-40mg/day ramipril 5-10 mg/day Hyperkalemia ; teratogen; cough, first-dose hypotension, rash ARBs Losartan Valsartan 50-100 mg daily 40-160 mg daily Hyperkalemia ; teratogen CCBs Amlodipine Nifedipine diltiazem , verapamil 5-10 mg daily 30-90 mg daily 200-300 mg daily 240 mg daily Excessive cardiac depression; constipation Wednesday, April 22, 2015 34

35. DRUG TREATMENT DRUG DOSE TOXICITIES BETA 1 SELECTIVE Atenolol Metoprolol Bisoprolol 50-100 mg daily 100-200 mg daily 5-10 mg daily Bradycardia, hypotension BETA BLOCKERS, ALPHA ACTIVITY Labetalol Carvedilol 200 mg-2.4 g daily in divided doses 6.25-25 mg 12-hourly sexual dysfunction, sedation, sleep disturbances, hypotension, weight gain VASODILATORS Hydralazine (25-100 mg 12-hourly first-dose and postural hypotension, headache, tachycardia and fluid retention Wednesday, April 22, 2015 35

36. HYPERTENSIVE EMERGENCIES Defn; Hypertensive emergencies are acute, life-threatening, and usually associated with marked increases in blood pressure , generally ≥180/120 mmHg Malignant hypertension is marked hypertension with retinal hemorrhages, exudates, or papilledema. Hypertensive encephalopathy refers to the presence of signs of cerebral edema caused by breakthrough hyperperfusion from severe and sudden rises in blood pressure. Wednesday, April 22, 2015 36

37. MECHANISMS OF VASCULAR INJURY With mild to moderate elevations in blood pressure, damage to the vascular wall. Disruption of the vascular endothelium then allows plasma constituents (including fibrinoid material) to enter the vascular wall, thereby narrowing or obliterating the vascular lumen . Within the brain, the breakthrough vasodilation from failure of autoregulation leads to the development of cerebral oedema and the clinical picture of hypertensive encephalopathy The level at which fibrinoid necrosis occurs is dependent upon the baseline BP Wednesday, April 22, 2015 37

38. Mechanism….. In comparison, hypertensive encephalopathy can be seen at diastolic pressures as low as 100 mmHg in previously normotensive patients with acute hypertension due to preeclampsia or acute glomerulonephritis; patients in whom autoregulation is impaired also may develop hypertensive injury at relatively mild degrees of hypertension Wednesday, April 22, 2015 38

39. HYPERTENSIVE RETINOPATHY GRADING Keith Wagener Barker (KWB) Grades Grade 1 Arteriolar constriction/attenuation/sclerosis ­`silver wiring` and vascular tortuosities Grade 2 As grade 1 + Irregularly located, tight constrictions ­ Known as `AV nicking` or `AV nipping` Grade 3 As grade 2 + Retinal edema , cotton wool spots and flame­ hemorrhages Grade 4 As grade 3 + swelling of the optic disk ( papilloedema ) + macular star Wednesday, April 22, 2015 39

40. Grade 3 KWB Retinopathy Wednesday, April 22, 2015 40

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42. GOAL OF THERAPY The initial aim of treatment in hypertensive crises is to rapidly lower the diastolic pressure to about 100 to 105 mmHg; this goal should be achieved within two to six hours, with the maximum initial fall in BP not exceeding 25 percent of the presenting value. This level of BP control will allow gradual healing of the necrotizing vascular lesions. More aggressive hypotensive therapy is both unnecessary and may reduce the blood pressure below the autoregulatory range, possibly leading to ischemic events (such as stroke or coronary disease). Once the BP is controlled, the patient should be switched to oral therapy, with the diastolic pressure being gradually reduced to 85 to 90 mmHg over two to three months. Wednesday, April 22, 2015 42

43. Parenteral drugs for treatment of hypertensive emergencies Drug Dose Adverse effects Onset of action VASODLATORS Sodium nitroprusside 0.25-10 µg/kg/min as IV infusion Nausea, vomiting, muscle twitching, sweating, thiocynate and cyanide intoxication Immediate Nicardipine hydrochloride 5-15 mg/h IV Tachycardia, headache, flushing, local phlebitis 5-10 min Clevidipine 1-2 mg/h IV with rapid titration to max of 16 mg/h Atrial fibrillation, nausea 1-2 min Fenoldopam mesylate 0.1-0.3 µg/kg per min IV infusion Tachycardia, headache, nausea, flushing <5 min Nitroglycerin 5-100 µg/min as IV infusion Headache, vomiting, methemoglobinemia, tolerance with prolonged use. 2-5 min Hydralazine hydrochloride 20-30 min IM Tachycardia, flushing, headache, vomiting, aggravation of angina 20-30 min IM Wednesday, April 22, 2015 43

44. Parenteral drugs for treatment of hypertensive emergencies…. Drug Dose Adverse effects Onset of action Andrenergic inhibitors Labetalol hydrochloride 20-80 mg IV bolus every 10 min 0.5-2.0 mg/min IV infusion Vomiting, scalp tingling, bronchoconstriction, dizziness, nausea, heart block, orthostatic hypotension 5-10 min Esmolol hydrochloride 250-500 µg/kg/min by infusion; may repeat bolus after 5 min or increase infusion to 300 µg/min Hypotension, nausea, asthma, first-degree heart block, HF 1-2 min Phentolamine 5-15 mg IV bolus Tachycardia, flushing, headache 1-2 min Wednesday, April 22, 2015 44

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