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Hypertensive Emergencies Or How I Learned to Stop Worrying and Love Labetalol Andrew T. Harris, MD PGY3 August 4, 2015 Objectives Define emergency vs urgency Overview of HTN urgency Brief review of classes of antihypertensives Review common scenarios and identify appropriate treatments Common issues with diuretics Take-home: sneak preview Hypertensive Urgency ORAL MEDS!! ◦ Rapid overcorrection can be very harmful ◦ Start low, go slow IV Hydralazine BAD ◦ Severe, unpredictable hypotension + reflex tachycardia Labetalol GOOD ◦ Except in acute decompensated HF Dilt gtt NEVER in acute HFrEF Always ask: “What is the EF?” Problems with inpatient HTN Difficult to determine true hypertensive emergency Nurses keep paging me!!! It’s not an emergency!!! AAAARGH! No accepted guidelines for management Cochrane Review 2008: Insufficient evidence to support a single drug as being more effective in HTN emergency Emergency vs Urgency What differentiates emergency from urgency? Hypertensive Urgency Best accepted definition ◦ Systolic BP > 180 OR ◦ Diastolic BP > 120 ◦ No evidence of end organ damage (mild headache does not count!) Most commonly due to poorly controlled chronic hypertension NOT an indication for hospital admission DO NOT use IV anti-hypertensives Hypertensive Urgency If admitted for other reasons, slowly lower BP with oral medications over days ◦ No good evidence to guide timeframe or choice of medication ◦ In general, lower systolic/MAP NMT 25% or to 160/100 Rapid correction below auto-regulatory range can cause ischemia ◦ Cerebral (stroke) ◦ Coronary (MI) ◦ Renal (AKI) Reasons to potentially lower over hours: ◦ Known aortic or cerebral aneurysm ◦ High risk of MI (known CAD, DMII) Clinical Scenario #1 65 yo F with HTN admitted for PNA. You are on nightfloat. Nurse calls, BP is 180/110.Your signout says “NTD” What should you do? Next Steps: Stall: ◦ ◦ ◦ ◦ ◦ ◦ ◦ What are the full vitals? Is she symptomatic? Can you recheck a manual BP? What size cuff did you use? Is she in pain? Did she get her regularly scheduled meds? I’m at a code, can I call you back? OK, it’s still elevated, now what? Hypertensive Urgency Remember: start low, go slow Fully titrate before adding a second med ◦ Titrate to effect (or side effect) Hypertensive Urgency Good medications ◦ ◦ ◦ ◦ ◦ Patient’s previous meds (nonadherence) Amlodipine ACE/ARB (check renal panel as outpt) Labetalol (expensive outpatient med) Diuretics Bad Medications ◦ Anything IV ◦ Hydralazine, nifedipine (most of the time) Clonidine ◦ It works, but watch out….. ◦ Severe rebound HTN, must be tapered Hypertensive Emergency This is an indication for ICU admission! Types of end organ damage ◦ Encephalopathy: Headache, altered mental status, visual disturbance Fundoscopic exam: look for papilledema ◦ ◦ ◦ ◦ ◦ ◦ Aortic or carotid dissection MI/ACS/chest pain Pulmonary edema with respiratory failure Renal Failure Pregnancy – ECLAMPSIA/HELLP Microangiopathic Hemolytic Anemia All things are poison and nothing is without poison; only the dose makes a thing not a poison. -Paracelsus Classes of Anti-Hypertensives Beta Blockers Alpha Blockers ACE-I/ARBs Calcium Channel Blockers Vasodilators Diuretics Beta Blockers Labetalol: Alpha 1 + non-selective Beta ◦ Decrease HR w/o decreasing CO ◦ Good in most settings (except HFrEF) Esmolol: short acting Beta 1 antagonist ◦ Very quick onset, primarily rate control better with a vasodilator ◦ Comes with lots of fluid IV Metoprolol: ◦ Rate control, not anti-hypertensive Calcium Channel Blockers Dihydropyridine ◦ Nicardipine SE: reflex tachycardia ◦ Clevidipine (mostly used in ED) Ultra-short onset (1 minute) ◦ Nifedipine AVOID – increased mortality Non-dihydropyridine – negative inotropes ◦ Diltiazem – bad news in HFrEF ◦ Remember the Frank Starling curve Frank-Starling Curve Vasodilators Nitroglycerin ◦ Primarily venodilator, reduces preload ◦ Arterial vasodilator at high doses, modest afterload reduction Nitroprusside ◦ Arterial and venous dilator ◦ Cyanide toxicity (photodegradation) – Inhibits oxidative phosph Hydralazine - BAD ◦ Prolonged, unpredictable drops in blood pressure ◦ Effect lasts up to 10 hours, best avoided Other ACE-Inhibitors ◦ Enalaprilat (only IV form) Diuretics (more to come shortly) ◦ Furosemide ◦ Torsemide ◦ Bumetanide Clinical Scenario #2 65 yo M, PMH of ischemic cardiomyopathy (EF 35%), HTN, DMII presents with acute SOB. T 98.8, BP 190/120, RR 25, PO2 sat 88% CXR – pulmonary edema What do you want to use? Pulmonary Edema Goals of therapy: ◦ Reduce afterload and preload ◦ Increase or maintain contractility ◦ Maintain stroke volume (permissive tachy) Low EF avoid beta blockers/negative inotropes Nitroglycerin (reduces preload) IV Diuretic (reduces preload and afterload) Labetalol if preserved EF NIPPV – reduces preload and afterload Clinical Scenario #3 65 yo F, PMH of HTN, DMII, PAD presents with chest pain at rest T 98.8, BP 190/120, RR 25, PO2 sat 94% ECG: ◦ new TwI in I, II, aVL,V3-V6 What do you want to use? Acute Coronary Syndrome Goals of therapy: ◦ Reduce Myocardial Oxygen Demand ◦ Reduce Heart Rate ◦ Reduce Afterload Labetalol (or Esmolol) Nitroglycerin ◦ Primarily anti-anginal ACE-Inhibitor if no contraindication ◦ Captopril short acting, easily titrated Clinical Scenario #4 65 yo M, Marfan’s syndrome, HTN, presents with severe CP radiating to back T 98.8, BP 190/120, RR 25, PO2 sat 94% CXR: widened mediastinum CT scan: descending aortic dissection What do you want to use? Aortic Dissection Goals of therapy: ◦ Reduce shear stress ◦ Reduce Heart Rate ◦ Reduce Velocity of Blood Flow Vasodilator alone will increase HR Vasodilator + beta blocker ◦ Labetalol OR ◦ Nicardipine + Esmolol OK to aggressively reduce (<120/80) Clinical Scenario #5 65 yo F with HTN, Carotid Stenosis admitted for PNA. You are called by the nurse for new onset L sided weakness T 98.8, BP 200/120, RR 18, PO2 sat 96% Besides calling a BAT, what medication would you give? CVA/Stroke HTN normal in acute stroke and protective (first 24-48 hrs) ◦ Loss of autoregulation in the ischemic penumbra Ischemic Stroke ◦ Goal BP for thrombolytic therapy <180/105 ◦ Labetalol or Nitroprusside if > 220/120 Hemorrhagic Stroke (depends on ICP) Ask your friendly neurologist for help Other Scenarios Encephalopathy (goal: reduce ICP) ◦ Labetalol or Nicardipine Sympathetic Crisis ◦ Cocaine, Amphetamines, PCP (Urine Tox!!) ◦ Others: MAO inhibitor + tyramine, clonidine withdrawal ◦ Avoid beta blockers – theoretical risk of sympathetic crisis, unopposed alpha agonism ◦ Good options: Nicardipine or Verapamil + benzo; Labetalol likely safe A Word on Diuresis Threshold Dose ◦ Minimum effective dose ◦ Often 40 IV Lasix ◦ No response double the dose Tolerance – hypertrophy of nephrons ◦ Add thiazide such as metolazone Conversions ◦ 40 Lasix = 20 Torsemide = 1 Bumex ◦ 40 Lasix PO = 20 Lasix IV ◦ Rule of thumb = give PO dose as IV Diuretic Drips Equivalent to bolus (DOSE trial) Good for quick titration in ICU Always bolus prior to starting drip or adjusting the rate Furosemide: 40 IV then 10/hr Torsemide: 20 IV then 5/hr Bumetanide: 1 IV, then 0.5/hr Remember: higher doses in renal failure! Take-home Points Hypertensive Urgency ORAL MEDS!! ◦ Rapid overcorrection can be very harmful ◦ Start low, go slow IV Hydralazine BAD ◦ Severe, unpredictable hypotension + reflex tachycardia Labetalol GOOD ◦ Except in acute decompensated HF Dilt gtt NEVER in acute HFrEF Always ask: “What is the EF?”
