What is the initial management of a patient presenting to the emergency room (ER) with hypertension?

Initial Management of Hypertension in the Emergency Room

The critical first step is determining whether acute target organ damage is present—this distinction between hypertensive emergency and hypertensive urgency completely dictates management. 1

Immediate Triage Assessment

Assess for acute target organ damage within minutes of presentation: 1

• Neurologic damage: Altered mental status, somnolence, headache with vomiting, visual disturbances, seizures, stroke, or hypertensive encephalopathy 1
• Cardiac damage: Chest pain suggesting acute MI, acute left ventricular failure with pulmonary edema, or unstable angina 2, 1
• Vascular damage: Aortic dissection (tearing chest/back pain) 1
• Renal damage: Acute kidney injury with rising creatinine 1
• Ophthalmologic damage: Bilateral retinal hemorrhages, cotton wool spots, or papilledema on fundoscopy (malignant hypertension) 1
• Obstetric damage: Eclampsia or severe preeclampsia 1

The absolute blood pressure number is less important than the presence or absence of organ damage—patients with chronic hypertension often tolerate higher pressures than previously normotensive individuals. 1

Management Algorithm

If Target Organ Damage Present = Hypertensive Emergency

Immediate ICU admission with continuous arterial line monitoring is mandatory (Class I recommendation). 1

First-line IV medications: 1

• Nicardipine: Start 5 mg/hr IV infusion, titrate by 2.5 mg/hr every 15 minutes to maximum 15 mg/hr 1, 3

  • Preferred for most emergencies except acute heart failure 1
  • Maintains cerebral blood flow, does not increase intracranial pressure 1
  • Particularly effective for hypertensive encephalopathy 1

• Labetalol: 10-20 mg IV bolus over 1-2 minutes, repeat/double every 10 minutes (max 300 mg cumulative), OR 2-4 mg/min continuous infusion 1

  • Preferred for aortic dissection, eclampsia/preeclampsia, and cerebrovascular events 1
  • Contraindicated in reactive airway disease, COPD, heart block, bradycardia, decompensated heart failure 1

• Clevidipine: 1-2 mg/hr IV, double every 90 seconds until BP approaches target, then increase by less than double every 5-10 minutes (max 32 mg/hr) 1

Blood pressure reduction targets: 1

• Standard approach: Reduce mean arterial pressure by 20-25% within the first hour, then if stable to 160/100 mmHg over 2-6 hours, then cautiously normalize over 24-48 hours 1
• Aortic dissection: More aggressive—target SBP ≤120 mmHg within 20 minutes 1
• Acute coronary syndrome: Target SBP <140 mmHg immediately with nitroglycerin 1
• Acute ischemic stroke: Avoid BP reduction unless SBP >220 mmHg, then reduce MAP by 15% over 1 hour 1

Critical pitfall: Avoid excessive acute drops >70 mmHg systolic—this precipitates cerebral, renal, or coronary ischemia, particularly in patients with chronic hypertension who have altered autoregulation. 1

If NO Target Organ Damage = Hypertensive Urgency

Oral antihypertensive therapy with outpatient follow-up is appropriate—hospital admission and IV medications are NOT necessary. 2, 4

First-line oral agents: 5, 4

• Captopril (ACE inhibitor): Start at low doses due to risk of precipitous drops in volume-depleted patients 5
• Labetalol (combined alpha/beta-blocker): Dual mechanism of action 5
• Extended-release nifedipine (calcium channel blocker): Never use short-acting nifedipine—it causes unpredictable precipitous drops, stroke, and death 5

Blood pressure reduction targets: 4

• Reduce SBP by no more than 25% within the first hour 4
• Aim for BP <160/100 mmHg over the next 2-6 hours if stable 4
• Cautiously normalize over 24-48 hours 4

Follow-up strategy: 4

• Schedule urgent outpatient review within 24-48 hours 4
• Arrange at least monthly follow-up until target BP achieved 4
• Screen for secondary hypertension causes after stabilization (20-40% have identifiable causes) 4

Common Pitfalls to Avoid

• Do not use IV medications for hypertensive urgency—up to one-third of patients with elevated BP normalize before follow-up, and rapid lowering may be harmful 2, 5
• Never use short-acting nifedipine—unpredictable precipitous drops cause stroke and death 1, 5
• Avoid hydralazine as first-line—unpredictable response and prolonged duration 1
• Use sodium nitroprusside only as last resort—cyanide toxicity risk with prolonged use or renal insufficiency 1
• Do not rapidly normalize BP in acute phase—patients with chronic hypertension have altered autoregulation and acute normotension causes ischemia 1

Special Considerations

• Cocaine/amphetamine intoxication: Benzodiazepines first, then phentolamine, nicardipine, or nitroprusside if needed—avoid beta-blockers 1
• Acute pulmonary edema: Nitroglycerin IV (5-100 mcg/min) or nitroprusside preferred 1
• Eclampsia/preeclampsia: Hydralazine, labetalol, or nicardipine—ACE inhibitors and ARBs absolutely contraindicated 1