Approach to the Severe Hypertension.pptx

Hypertension

1. Severe Hypertension Brook A. June/2016 Braunwald 10th ed.

2. Introduction Severe hypertension is often defined as systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥120 mmHg. Hypertensive Urgency Hypertensive Emergency Most patients who present with severe hypertension are chronically hypertensive, and in the absence of acute end organ damage, precipitous lowering of blood pressure may be associated with significant morbidity and should be avoided.

3. Hypertensive Urgency Some patients with an equivalent degree of hypertension are relatively asymptomatic (other than perhaps headache) and have no acute signs of end-organ damage. This entity is called hypertensive urgency Occurs most commonly among patients who have been nonadherent with their chronic antihypertensive regimen or those who are nonadherent with a low sodium diet (as hypertensive emergency)

4. Hypertensive Emergencies Hypertensive emergencies are acute, life-threatening, and usually associated with marked increases in blood pressure (BP), generally ≥180/120 mmHg Two major clinical syndromes induced by the severe hypertension:- Malignant Hypertension Hypertensive Encephalopathy

5. Htn Emergencies

6. Malignant hypertension A syndrome associated with an abrupt increase of blood pressure in a patient with underlying hypertension or related to the sudden onset of hypertension in a previously normotensive individual. The absolute level of blood pressure is not as important as its rate of rise. Pathologically, the syndrome is associated with diffuse necrotizing vasculitis, arteriolar thrombi, and fibrin deposition in arteriolar walls. Fibrinoid necrosis has been observed in arterioles of kidney, brain, retina, and other organs

7. Malignant… Clinically, the syndrome is recognized by progressive retinopathy (arteriolar spasm, hemorrhages, exudates, and papilledema), deteriorating renal function with proteinuria, microangiopathic hemolytic anemia, and encephalopathy In addition to marked elevation in BP, the major clinical manifestations include Retinal hemorrhages and exudates and papilledema Malignant nephrosclerosis, leading to acute kidney injury, hematuria, and proteinuria Intracerebral or subarachnoid bleeding, lacunar infarcts, or hypertensive encephalopathy

8. Malignant… Malignant nephrosclerosis, leading to acute kidney injury, hematuria, and proteinuria Renal biopsy reveals fibrinoid necrosis in the arterioles and capillaries, producing histologic changes that are indistinguishable from any of the forms of the hemolytic-uremic syndrome The renal vascular disease leads to glomerular ischemia and activation of the RAAS, resulting in exacerbation of htn Neurologic symptoms due to intracerebral or subarachnoid bleeding, lacunar infarcts, or hypertensive encephalopathy (HE) HE: related to cerebral edema Insidious onset of headache, nausea, and vomiting, followed by nonlocalizing neurologic symptoms such as restlessness, confusion, and, if the hypertension is not treated, seizures and coma MRI scan should be obtained to exclude ischemic stroke or hemorrhage, which are not usually treated with aggressive BP reduction

9. Malignant… Although papilledema had been thought to represent a more severe lesion, it does not appear to connote a worse prognosis than hemorrhages and exudates alone (so-called accelerated hypertension) . Thus, treatment is the same whether or not papilledema is present.

10. Treatment: Severe Htn The key to successful management of severe hypertension is to differentiate hypertensive emergencies from hypertensive urgencies. The degree of target organ damage, rather than the level of blood pressure alone, determines the rapidity with which blood pressure should be lowered

11. Hypertensive Urgency: Rx The rapidity with which blood pressure should be brought to safe levels (eg, <160/100 mmHg) is controversial Rapid reduction in blood pressure (BP) was recommended in the past However, in the absence of symptoms a more gradual reduction in pressure is suggested.

12. Hypertensive Urgency: Rx Cerebral or myocardial ischemia or infarction can be induced by aggressive antihypertensive therapy if the blood pressure falls below the range at which tissue perfusion can be maintained by autoregulation This has been most often described with sublingual nifedipine Thus, in the absence of signs of acute end-organ damage, the goal of management is to reduce the blood pressure to ≤160/100 mmHg over several hours to days

13. Hypertensive Urgency: Rx General Strategies All patients should be provided a quiet room to rest; this can lead to a fall in BP of 10 to 20 mmHg or more Previously treated hypertension Increase the dose of existing antihypertensive medications, or add another agent. Reinstitution of medications in non-adherent patients. Addition of a diuretic, and reinforcement of dietary sodium restriction, in patients who have worsening hypertension due to high sodium intake.

14. Hypertensive Urgency: Rx Untreated Hypertension take into consideration the individual patient's risk with persistence of severe hypertension, the likely duration of severe hypertension, and of cerebrovascular or myocardial ischemia with rapid reduction in blood pressure Relatively rapid initial blood pressure reduction (over several hours). Oral furosemide  (if the patient is not volume depleted) at a dose of 20 mg (or higher if the renal function is not normal); A small dose of oral clonidine  (0.2 mg); or A small dose of oral captopril  (6.25 or 12.5 mg). Following administration of one of these agents, the patient is observed for a few hours, to ascertain a reduction in blood pressure of 20 to 30 mmHg. Thereafter, a longer acting agent is prescribed (see below) and the patient is sent home to follow up within a few days.

15. Hypertensive Urgency: Rx Most appropriate in the long term Calcium channel blockers and thiazide-like diuretics are preferred over ACE inhibitors and beta blockers as monotherapy in blacks Underlying conditions that may be favorably or adversely affected by the antihypertensive agent Some experts initiate therapy with two agents or a combination agent, one of which is a thiazide diuretic

16. Hypertensive Urgency: Rx Monitoring and Follow-up Usually managed in the emergency room Patients at high risk for cardiovascular events (eg, long-standing diabetes, known coronary artery disease or prior stroke), should probably be admitted The patient should be observed for a few hours to ascertain that the blood pressure is stable or improving, and that indeed they are asymptomatic The patient can be sent home with close follow-up over the subsequent days symptoms related to hypertension or hypotension, and adjustment of medications to achieve the initial blood pressure goal of ≤160/100 mmHg

17. Hypertensive Emergency: Rx In hypertensive individuals, the upper and lower limits of autoregulation of cerebral blood flow are shifted to higher levels of arterial pressure, and rapid lowering of blood pressure to below the lower limit of autoregulation may precipitate cerebral ischemia or infarction as a consequence of decreased cerebral blood flow Renal and coronary blood flows also may decrease with overly aggressive acute therapy

18. Hypertensive Emergency: Rx Goal of therapy The initial goal of therapy is to reduce mean arterial blood pressure* by no more than 25% within minutes to 2 h or to a blood pressure in the range of 160/100–110 mmHg. (Harrison’s 18th) 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. (UpToDate 19.3) Parenteral hypotensive drugs are preferred 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

19. Hypertensive Emergency: Rx In patients with malignant hypertension without encephalopathy or another catastrophic event, it is preferable to reduce blood pressure over hours or longer rather than minutes. This goal may effectively be achieved initially with frequent dosing of short-acting oral agents such as captopril, clonidine, and labetalol. Although specific blood pressure targets have not been defined for patients with acute cerebrovascular events, aggressive reductions of blood pressure are to be avoided

20. Hypertensive Emergency: Rx For patients with cerebral infarction Not candidates for thrombolytic therapy, antihypertensive therapy only for patients with a SBP>220 mmHg or a DBP >130 mmHg. If thrombolytic therapy is to be used, the blood pressure goal is SBP<185 mmHg and DBP<110 mmHg In Hemorrhagic stroke, initiate antihypertensive therapy at systolic >180 mmHg or diastolic pressure >130 mmHg. For Subarachnoid hemorrhage: controversial

21. Hypertensive Emergency: Rx Several parenteral antihypertensive agents are most often used in the initial treatment of malignant hypertension Nitroprusside  — an arteriolar and venous dilator, given as an intravenous infusion. Initial dose: 0.25 to 0.5 µg/kg per min; maximum dose: 8 to 10 µg/kg per min. acts within seconds and has a duration of action of only two to five minutes. hypotension can be easily reversed by temporarily discontinuing the infusion, providing an advantage over the other drugs Nicardipine  — an arteriolar dilator, given as an intravenous infusion. Initial dose: 5 mg/h; maximum dose: 15 mg/h. Clevidipine  — a short-acting dihydropyridine calcium channel blocker. It reduces blood pressure without affecting cardiac filling pressures or causing reflex tachycardia. Initial dose: 1 mg/hour; maximum dose: 21 mg/hour.

22. Hypertensive Emergency: Rx Labetalol  — an alpha- and beta-adrenergic blocker, given as an intravenous bolus or infusion. Bolus: 20 mg initially, followed by 20 to 80 mg every 10 minutes to a total dose of 300 mg. Infusion: 0.5 to 2 mg/min. Fenoldopam  — a peripheral dopamine-1 receptor agonist, given as an intravenous infusion. Initial dose: 0.1 µg/kg per min; the dose is titrated at 15 min intervals, depending upon the blood pressure response.

23. Hypertensive Emergency: Rx

24. Hypertensive Emergency: Rx Oral Agents A slower onset of action and an inability to control the degree of BP reduction has limited the use of oral antihypertensive agents in the therapy of hypertensive emergencies useful when there is no rapid access to the parenteral medications described above Both sublingual nifedipine  (10 mg) and sublingual captopril  (25 mg) can substantially lower the BP within 10 to 30 minutes in many patients Liquid nifedipine should be avoided due to more aggressive BP reduction leading to ischemia (eg, angina pectoris, myocardial infarction, or stroke)

25. Hypertensive Emergency: Rx Long term oral management: as Htn urgency Most appropriate in the long term Calcium channel blockers and thiazide-like diuretics are preferred over ACE inhibitors and beta blockers as monotherapy in blacks Underlying conditions that may be favorably or adversely affected by the antihypertensive agent Some experts initiate therapy with two agents or a combination agent, one of which is a thiazide diuretic

26. BP control in Stroke

27. Ischemic Stroke Antihypertensive medications should be restarted at approximately 24 hours after stroke onset in patients with preexisting hypertension who are neurologically stable, unless a specific contraindication to restarting treatment is known Most consensus guidelines recommend that blood pressure NOT be treated acutely in the patient with ischemic stroke

28. Indications for acute management of hypertension in patients with ischemic stroke Malignant Htn (systolic blood pressure >220 mmHg or diastolic blood pressure >120 mmHg), or Active ischemic coronary disease, Heart failure, Aortic dissection, Hypertensive encephalopathy, Acute renal failure, or Pre- eclampsia / eclampsia

29. If pharmacologic therapy is given, intravenous labetalol  is generally the drug of choice In patients with ischemic stroke eligible for thrombolytic therapy:- Before lytic therapy is started, treatment is recommended so that systolic blood pressure is ≤185 mmHg and diastolic blood pressure is ≤110 mmHg. The blood pressure should be stabilized and maintained below 180/105 mmHg for at least 24 hours after intravenous tPA treatment.

30. Hemorrhagic Stroke For patients with SBP >200 mmHg or MAP >150 mmHg consider aggressive reduction of blood pressure with continuous intravenous infusion of medication Frequent (every five minutes) blood pressure monitoring For patients with SBP >180 mmHg or MAP >130 mmHg and evidence or suspicion of elevated ICP Consider monitoring ICP and reducing blood pressure using intermittent or continuous intravenous medication to keep cerebral perfusion pressure in the range of 61 to 80 mmHg

31. For patients with SBP >180 mmHg or MAP >130 mmHg and no evidence or suspicion of elevated ICP Consider a modest reduction of blood pressure ( eg , target MAP of 110 mmHg or target blood pressure of 160/90 mmHg) using intermittent or continuous intravenous medication, and Clinically reexamine the patient every 15 minutes

32. Labetalol , nicardipine , esmolol , enalapril , hydralazine , nitroprusside , and nitroglycerin  are useful intravenous agents for controlling blood pressure

33. Thank You!