Hypertension

1. Hypertension Resting BP consistently >140 mmHg systolic or >90 mmHg diastolic

2. Epidemiology • 20% of adult population • ~35,000,000 people • 25% do not know they are hypertensive • Twice as frequent in blacks than in whites • 25% of whites and 50% of blacks > 65 y/o

3. Types • Primary (essential) hypertension • Secondary hypertension

4. Primary Hypertension • 85 - 90% of hypertensives • Idiopathic • More common in blacks or with positive family history • Worsened by increased sodium intake, stress, obesity, oral contraceptive use, or tobacco use • Cannot be cured

5. Secondary Hypertension • 10 - 15% of hypertensives • Increased BP secondary to another disease process

6. Secondary Hypertension • Causes: • Renal vascular or parenchymal disease • Adrenal gland disease • Thyroid gland disease • Aortic coarctation • Neurological disorders • Small number curable with surgery

7. Hypertension Pathology • Increased BP  inflammation, sclerosis of arteriolar walls  narrowing of vessels  decreased blood flow to major organs • Left ventricular overwork  hypertrophy, CHF • Nephrosclerosis  renal insufficiency, failure

8. Hypertension Pathology • Coronary atherosclerosis  AMI • Cerebral atherosclerosis  CVA • Aortic atherosclerosis  Aortic aneurysm • Retinal hemorrhage  Blindness

9. Signs/Symptoms • Primary hypertension is asymptomatic until complications develop • Signs/Symptoms are non-specific • Result from target organ involvement • Dizziness, flushed face, headache, fatigue, epistaxis, nervousness are not caused by uncomplicated hypertension.

10. HTN Medical Management • Life style modification • Weight loss • Increased aerobic activity • Reduced sodium intake • Stop smoking • Limit alcohol intake

11. HTN Medical Management • Medications • Diuretics • Beta blockers • Calcium antagonists • Angiotensin converting enzyme inhibitors • Alpha blockers

12. HTN Medical Management Medical management prevents or forestalls all complications Patients must remain on drug therapy to control BP

13. Categories of Hypertension • Hypertensive Emergency (Crisis) • acute  BP with sx/sx of end-organ injury • Hypertensive Urgency • sustained DBP > 115 mm Hg w/o evidence of end-organ injury • Mild Hypertension • DBP > 90 but < 115 mm Hg w/o symptoms • Transient Hypertension • elevated due to an unrelated underlying condition

14. Hypertensive Crisis Acute life-threatening increase in BP Usually exceeds 200/130 mmHg

15. Hypertensive Emergency • Severe hypertension associated with end organ damage • Malignant hypertension (htn with retinal hemorrhages, exudates or papilledema, also renal involvement) • Hypertensive encephalopathy • Subarachnoid/Intracerebral hemorrhage • Acute pulmonary edema • Dissecting aneurysm • Angina

16. Hypertensive Urgency • Diastolic bp equal to or above 130 mm Hg • No signs of end organ damage

17. When you are called.. • Ask about mental status changes, chest pain • Obtain all vital signs • Determine the reason for admission • Ask about the patient’s blood pressure over the last 24 hours

18. When you get to the bedside • Measure the bp again in BOTH ARMS • jvd, thyromegaly, fundoscopic exam • New cardiac murmer, S3, S4, tachycardia • Renal or aortic bruits • Edema to the extremities • Brief mental status exam, gross motor exam

19. If you determine this to be a hypertensive urgency… • There is no evidence of end organ damage • There is NO PROVEN BENEFIT to rapid reduction in bp in asymptomatic patients. • Aggressive antihypertensive therapy can induce cerebral or myocardial ischemia

20. If you determine this to be a hypertensive urgency… • Your goal is to get the patient to around 160/110 mmHg over several hours with conventional oral therapy

21. Labs… • Lytes, BUN/CR • Cardiac enzymes if pt has angina/chf • CXR if indicated if pt in angina/chf • EKG if indicated if pt has angina/chf • CT head if signs of encephalopathy

22. Causes • Sudden withdrawal of anti-hypertensives • Increased salt intake • Abnormal renal function • Increase in sympathetic tone • Stress • Drugs • Drug interactions • Monoamine oxidase inhibitors • Toxemia of pregnancy • Pheochromocytoma

23. Restlessness, confusion, AMS Vision disturbances Severe headache Nausea, vomiting Seizures Focal neurologic deficits Chest pain Dyspnea Pulmonary edema Signs/Symptoms

24. Hypertensive Crisis Can Cause • CHF • Pulmonary edema • Angina pectoris • AMI • Aortic dissection

25. Hypertensive Emergencies Stroke Encephalopathy Aortic Dissection Decompensated Heart Failure Acute Coronary Syndrome Acute Renal Failure

26. Hypertensive Crisis Management • Immediate goal: lower BP in controlled fashion • No more than 30%  in first 30-60 mins • Not appropriate in all settings • Oxygen • Monitor ECG • Drug Therapy • Targeted at simply lowering BP, OR • Targeted at underlying cause

27. Drug Therapy Possibilities • Sodium Nitroprusside • Potent arterial and venous vasodilator • Vasodilation begins in 1 to 2 minutes • 0.5 g/kg/min by continuous infusion, titrate to effect • increase in increments of 0.5 g/kg/min • 50 mg in 250 cc D5W • Effects easily reversible by stopping drip • Continuous hemodynamic monitoring required • Cover IV bag/tubing to avoid exposure to light • Used primarily when targeting lower BP only

28. Drug Therapy Possibilities • Nitroglycerin • Vasodilator • Nitropaste simplest method • 1 to 2 inches of ointment q 8 hrs • easy to control effect but slow onset • Sublingual NTG is faster route • 0.4 mg SL tab or spray q 5 mins • easy to control but short acting • NTG infusion, 10 - 20 mcg/min • seldom used for hypertensive crisis • Commonly used prehospital when targeting BP lowering only especially in AMI

29. Drug Therapy Possibilities • Nifedipine • Calcium channel blocker • Peripheral vasodilator • 10 mg Sublingual • Split capsule longitudinally and place contents under tongue or puncture capsule with needle and have patient chew • Used less frequently today! Frequently in past! • Concern for rapid reduction of BP resulting in organ ischemia

30. Drug Therapy Possibilities • Furosemide • Loop Diuretic • initially acts as peripheral vasodilator • later actions associated with diuresis • 40 mg slow IV or 2X daily dose • most useful in acute episode with CHF or LVF • Often used with other agents such as NTG

31. Drug Therapy Possibilities • Hydrazaline • Direct smooth muscle relaxant • relax arterial smooth muscle > venous • 10-20 mg slow IV q 4-6 hrs; initial dose 5 mg for pre-eclampsia/eclampsia • Usually combined with other agents such as beta blockers • concern for reflex sympathetic tone increase • Most useful in pre-eclampsia and eclampsia

32. Drug Therapy Possibilities • Metoprolol, orLabetalol • decrease in heart rate and contractility • Dose • Metoprolol: 5 mg slow IV q 5 mins to total ~15 mg • Labetalol: 10-20 mg slow IV q 10 mins • Metoprolol is selective beta-1 • minimal concern for use in asthma and obstructive airway disease • Labetalol: both alpha & beta blockade • Most useful in AMI and Unstable angina

33. Hypertensive Emergency • Enalapril • IV prep of ACE Inhibitor • Response is variable (probably b/c these pts have variable plasm renin activity) • Contraindicated in pregnancy • Start at 1.25 mg iv and up to 5 mg iv q 6 hrs • Onset of action: 15 minutes, peak effect 4 hrs • Duration of action: 12-24 hours

34. Hypertensive Crisis Management Avoid crashing BP to hypotensive or normotensive levels! Ischemia of vital organs may result!

35. Hypertensive Crisis Management Must assure underlying cause of BP is understood HTN may be helpful to the patient Aggressive treatment of HTN may be harmful What patients may have HTN as a compensatory mechanism?