Definition

Strictly speaking, hypertension is defined as BP >130/80. However, not every pt with a BP >130/80 warrants acute intervention.

• Hypertensive emergency: elevated BP is associated with end-organ damage (brain, eye, heart, and kidney)
• Hypertensive urgency: elevated BP of > 180/120 mmHg but no evidence of end-organ damage

Differential Diagnosis

• For hypertensive emergency, consider these important sequelae: 
  • Hypertensive encephalopathy
  • Dissecting aortic aneurysm
  • Acute left ventricular failure with pulmonary edema
  • Acute myocardial infarction
  • Eclampsia
  • Acute renal failure
  • Symptomatic microangiopathic hemolytic anemia
• Consider underlying conditions that could be causing hypertension:
  • Alcohol withdrawal (tachycardia, tremor, confusion).
  • Drug overdose (cocaine, amphetamine).
  • Medication interactions (MAO inhibitors, tricyclics).
  • Medication withdrawals (ß-blockers, ACE inhibitors, clonidine).
  • Increased intracranial pressure (Cushing’s reflex).
  • ESRD, renal failure, renal artery stenosis.
  • Eclampsia, pre-eclampsia (is the patient pregnant?)
  • Coarctation of the aorta, aortic dissection (unequal BP in arms?).
  • Pheochromocytoma (episodic nature; associated with flushing, diaphoresis, tachycardia).
  • Endocrine (Cushing’s syndrome, thyrotoxicosis, Conn’s syndrome-primary hyperaldosteronism).
  • Pain, anxiety (a diagnosis of exclusion).
  • Autonomic dysfunction

Evaluation

• High BP seldom warrants acute intervention. Your major concerns should be:
  • Whether this represents a hypertensive emergency.
  • Whether the hypertension reflects a more serious underlying process.  
  • Avoid reflexively treating elevated BP since rapid lowering can be associated with significant morbidity and death (especially if recent stroke or pancreatitis). Recognize that patients with chronic hypertension often tolerate higher elevations in blood pressure than normotensive patients. Treatment should be initiated sooner for patients with a rapid rise in BP and pregnant patients.
• Accurate reading? Using correct sized cuff, take the BP again in BOTH arms.
• Perform a chart biopsy: note the time course of hypertension. Has it been constant since admission, or has it developed suddenly? Does the patient have a history of renal or cardiac disease?
• Physical exam: ask about and examine:
  • Brain: headache, confusion, lethargy, stroke (Perform focused neurologic exam).
  • Eye: blurred vision (fundoscopic exam: papilledema, flame hemorrhages).
  • Heart: chest pain, dyspnea, S3, S4, pulses.
  • Kidney: low urine output, edema.
• Studies: not always required. Use selectively to determine cause and whether patient meets criteria for hypertensive emergency.
  • CBC with peripheral smear (look for schistocytes)
  • ECG, troponin, BNP
  • Urinalysis (look for proteinuria), electrolytes, BUN, and creatinine (look for renal dysfunction)
  • CXR if chest pain or dyspnea
  • Head CT for those with neurologic symptoms
  • Chest CT with contrast in patients with severe chest pain, unequal BP in arms, unequal pulses, or widening of mediastinum on CXR.

Management

For hypertensive urgencies: The majority of patients with hypertension have no acute end-organ damage and their blood pressure can be lowered over days with oral medications. Rapid lowering could cause MI or stroke in these patients. Consider rechecking BP after 30 minutes of quiet rest. Restarting a patient’s home medications is a good first step. Alternatively, consider starting one or more guideline-concordant long-acting oral medications that can be continued on discharge:

• Amlodipine 5-10 mg PO daily
• Lisinopril 10-20 mg PO daily or Losartan 25-50 mg daily

In cases where more rapid lowering and closer titration of blood pressure is desired, consider shorter-acting medications:

• Captopril 6.25-25 mg PO TID; you can titrate up after each dose if not having an adequate effect.
• Clonidine 0.1 mg PO BID. Can titrate up to TID. Due to the risk of rebound hypertension, clonidine is often reserved for resistant hypertension.
• Hydralazine 10 mg PO q8h, can increase to q6h - use with caution due to unpredictable effect and reflex tachycardia.
• Nitropaste quickly lowers preload, which can be particularly helpful in flash pulmonary edema triggered by elevated BP; it acts quickly and can be removed equally quickly. Start with ½ inch of paste applied to the chest. There is thought to be minimal benefit above 1 inch of paste. Adverse effects include headache. Avoid in patients with severe/critical AS due to their preload dependent state. Not appropriate for long term use. See Sliding Scales: Nitropaste for dosing.
• Avoid short-acting nifedipine (increased mortality).

For hypertensive emergencies: Requires admission to the ICU and arterial line insertion for close monitoring of BP.

• Important to note that many patients are also volume depleted and may require isotonic IV fluids to prevent hypotension following medication administration. (Assess CVP and be careful in those with heart, kidney, or liver disease).
• There is controversy surrounding the management, but it is recommended that MAP be reduced by only 10-20% over the first hour. Then, if stable, reduce MAP to ~120mmHg over the next 2-6 hours. BP should not be quickly lowered to normal levels, since autoregulation of blood flow to brain, heart, kidneys has likely compensated for chronic hypertension.
• Rapid declines in BP can lead to stroke, MI, or renal failure.
• EXCEPTIONS to gradual BP lowering:
  • Recent ischemic stroke: do not lower BP unless >185/110 if receiving reperfusion therapy, or >220>120 if not receiving reperfusion therapy.
  • Acute aortic dissection: want to rapidly lower BP to target SBP <120 within the first hour.
  • Pheochromocytoma and eclampsia: rapidly lower BP to target SBP <140 within the first hour.
• Use the following medications to get patients out of hypertensive emergencies then transition to PO medications.
  • Nicardipine: Initial infusion of 5mg/hour, increasing by 2.5mg/hour every 5 minutes to a maximum dose of 15mg/hour. Watch out for reflex tachycardia.
  • Clevidipine: Initial infusion of 1-2mg/hr, can be doubled every 2 minutes until BP is near target up to a maximum dose of 32 mg/hr.
  • Nitroprusside: 0.3 mcg/kg/min-4mcg/kg/min. Good afterload reducing agent and often first line in patients with acute heart failure. Higher rates or durations >24-48 hours not recommended because of cyanide toxicity. Avoid in patients with acute myocardial infarction due to the risk of coronary steal syndrome. Use with caution in patients with renal and liver disease.
  • Nitroglycerin: 5µg/min-60µg/min IV. Both preload (venous) and afterload (arterial) reduction. Use for hypertensive emergencies associated with acute coronary syndrome or acute pulmonary edema.
  • Labetalol: 10-20 mg IV initial, followed by 10-80mg IV q10 minutes until BP falls; alternatively, after initial bolus start infusion dosed at 0.5-10 mg/min. First-line agent for acute aortic dissection. Good for pregnant patients since little placental transfer. Not as effective at afterload reduction as some other agents. Do not use in patients with CHF due to the risk of precipitating cardiogenic shock.
  • Esmolol: 0.5mg/kg loading dose, followed by starting infusion of 50µg/kg/min up to 200µg/kg/min. Good for acute aortic dissection, post-operative hypertension, and myocardial infarction patients due to its quick onset of action. Depending on dose, esmolol ends up being a large volume infusion. Do not use in patients with heart failure.
  • AVOID hydralazine or nitropaste (unpredictable effects) and nifedipine (associated with increased mortality).

Special situations

• Ischemic stroke: hypertension in these patients is compensatory and helps preserve cerebral perfusion. Treatment should be reserved for when diastolic BP exceeds 120 and systolic BP >220 in the absence of thrombolytic therapy. Avoid nitroprusside, fenoldopam, and nitroglycerin, since these medications can increase intracranial BP (see Neurology chapter).
• Pheochromocytoma: use an α-blocker such as phenoxybenzamine or phentolamine.  Avoid β-blockers for fear of precipitating a hypertensive crisis (unopposed alpha). Requires rapid lowering of SBP to <140mmHg in the first hour.
• Pregnancy: use labetalol or nicardipine.
• Cocaine and amphetamines: caution with selective beta blockers given theoretical concern for unopposed alpha stimulation causing coronary artery vasoconstriction; consider hydralazine, nitroglycerin, or labetalol (which also has alpha blocking activity), as well as benzodiazepines.
• Scleroderma renal crisis: use an ACE inhibitor.
• Acute Aortic dissection: use esmolol or labetalol prior to addition of a vasodilator such as nicardipine or clevidipine.

Key Points

• Hypertension seldom requires aggressive acute intervention, unless concern for hypertensive emergency.
• For hypertensive emergency, admit patients to ICU for close monitoring, and avoid lowering blood pressure too rapidly.
• Go see any patients who you are worried may have hypertensive urgency/emergency and all patients who are symptomatic.

Peixoto AJ. Acute Severe Hypertension. New England Journal of Medicine. 2019;381(19):1843-1852. doi:10.1056/NEJMcp1901117

Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension 2018;71(6):e13-e115. DOI: 10.1161/HYP.0000000000000065