Hypertensive crisis resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ayokunle Olubaniyi, M.B,B.S [2]; Rim Halaby, M.D. [3]

Overview

Hypertensive crisis is the severe elevation in the blood pressure (systolic blood pressure >179 mm Hg, or diastolic blood pressure >109 mm Hg). Discontinuation of antihypertensive medications is the most common cause of hypertensive crisis.

Classification

Hypertensive crisis is further classified as hypertensive urgency or hypertensive emergency based on either the absence or presence of acute end-organ damage.

Hypertensive Urgency

Hypertensive urgency is the severe elevation in the blood pressure (systolic blood pressure >179 mm Hg, or diastolic blood pressure >109 mm Hg) without any evidence of acute end-organ damage.

Hypertensive Emergency

Hypertensive emergency is the severe elevation in the blood pressure (systolic blood pressure >179 mm Hg, or diastolic blood pressure >109 mm Hg) complicated by acute end-organ dysfunction, such as hypertensive encephalopathy, eclampsia, dissecting aortic aneurysm, acute left ventricular failure with pulmonary edema, acute myocardial infarction, acute renal failure, or symptomatic microangiopathic hemolytic anemia.

Causes

Life Threatening Causes

Hypertensive crisis is a life-threatening condition and must be treated as such irrespective of the cause.

Common Causes

• Antihypertensive medications withdrawal ( beta blockers, clonidine)
• Noncompliance with antihypertensive medications
• Pheochromocytoma
• Side effects of monoamine oxidase inhibitors
• Stimulants (cocaine, methamphetamine, phencyclidine)

Management

Characterize the symptoms: ❑ CNS: severe headache, dizziness, confusion, weakness/numbness, dysphagia, altered level of consciousness ❑ Eyes: pain, blurred/loss of vision ❑ Cardiopulmonary: chest pain, dyspnea ❑ Renal: hematuria, proteinuria, reduced urinary output ❑ Other: nausea, vomiting, anxiety, nosebleeds Obtain a detailed history: ❑ Past medical history of hypertension ❑ Use of medications (prescription or over the counter) ❑ Compliance to anti-hypertensive medications if applicable ❑ Recreational drug use (methamphetamine, cocaine, phencyclidine)

Examine the patient: ❑ Blood pressure ♦ Measured by the physician ♦ Both arms ♦ Appropriate cuff size ❑ Fundoscopic exam (looking for papilledema, exudates, hemorrhages) ❑ Complete neurological and mental status exam ❑ Cardiopulmonary signs of pulmonary edema, murmurs, gallops ❑ Abdomen (looking for pulsatile masses, tenderness, bruits) ❑ Peripheral pulses

Order Labs: ❑ CBC ❑ Electrolytes ❑ BUN ❑ Creatinine ❑ EKG (in case of chest pain) ❑ CXR (in case of chest pain or dyspnea) ❑ CT or MRI (in case of suspicion of aortic dissection) Consider additional tests based on each patient's presentation: ❑ Urine electrolytes, creatinine, protein ❑ CT/MRI ❑ Renal ultrasound + doppler ❑ TSH, free T3, free T4 ❑ Serum cortisol ❑ Serum aldosterone ❑ Serum renin ❑ 24-hr urinary catecholamine & metanephrine ❑ Serum parathyroid hormone ❑ Urine and serum toxicology screen ❑ Urine pregnancy test ❑ ANA/ESR/CRP/anti-dsDNA/anti-smith/rheumatoid factor/p-ANCA/c-ANCA

Evidence of end organ damage?

YES

NO

Hypertensive emergency

Hypertensive urgency

❑ Admit to ICU

❑ Treat as outpatient or admit for observation

❑ Monitor the blood pressure closely ❑ Intra-arterial blood pressure monitoring in severely-ill patients ❑ Assess volume status ❑ IV N/S if volume depleted to prevent precipitous fall in blood pressure following administration of antihypertensives ❑ Commence continuous infusion of short acting IV antihypertensives based on patient's end organ damage ❑ Change IV medications to oral when blood pressure is stable NB - Not more than 25% reduction in blood pressure within the 1st hour; when blood pressure is stable, reduce to 160/100-110 mmHg within the next 2-6 hours ❑ When the patient is stable and the blood pressure is well tolerated, reduce the blood pressure to normal within 24-48 hours

❑ Administer Oral antihypertensives ❑ Monitor the patient clinically within the first few hours of commencing medications NB - Gradual blood pressure reduction over 24 - 48 hours

Failure to control the blood pressure ❑ Consider a combination of antihypertensive medications

Good control of the blood pressure ❑ Review old or start new medications ❑ Modify risk factors ❑ Schedule a follow up

Intravenous Antihypertensive Drugs

Shown below is a table of the IV antihypertensive drugs and their appropriate doses.

Drug	Dose
Clevidipine	1 to 2 mg/h as IV infusion, max 16 mg/h
Enalaprilat	1.25–5 mg every 6 hrs IV
Fenoldopam	0.1–0.3 µg/kg per min IV infusion
Hydralazine	10–20 mg IV
Nicardipine	5–15 mg/h IV
Nitroglycerin	5–100 µg/min as IV infusion
Nitroprusside	0.25–10 µg/kg/min as IV infusion
Esmolol	250–500 µg/kg/min IV bolus, then 50–100 µg/kg/min by infusion May repeat bolus after 5 min or increase infusion to 300 µg/min
Labetalol	20–80 mg IV bolus every 10 min 0.5–2.0 mg/min IV infusion
Phentolamine	5–15 mg IV bolus

Oral Antihypertensive Drugs

Shown below is a table of the oral antihypertensive drugs and their appropriate doses.

Drug	Dose
Captopril	12.5 to 25 mg PO or SL, repeat as needed. max dose - 50 mg PO
Clonidine	0.1-0.2 mg PO x 1, then 0.05 to 0.1 mg/1-2 hrs. Max dose - 0.6 to 0.7 mg
Labetalol	200 mg PO, then 200 mg/hr until desired effect. Max dose - 1200 mg

• Other agents to consider include:

1. PO frusemide 20mg (repeat as necessary)
2. PO nifedipine SR 30mg, single dose
3. PO felodipine 5 mg, single dose

Management of Specific Hypertensive Emergencies

Hypertensive emergencies	Preferred agents
Aortic dissection	Labetalol, or nicardipine + esmolol, or nitroprusside + esmolol or nitroprusside + IV metoprolol Note: Administer beta blocker to control the heart rate before initiating a vasodilator e.g. nitroprusside Reduce blood pressure to 120 mmHg within 20 minutes with protection against reflex tachycardia.
Acute pulmonary edema / systolic dysfunction	Nitroglycerin + (Nicardipine or, fenoldopam, or nitroprusside) + loop diuretic
Acute pulmonary edema / diastolic dysfunction	Low-dose Nitroglycerin + (esmolol, metoprolol, labetalol, or verapamil) + loop diuretic
Acute coronary syndrome	Nitroglycerin + (labetalol or esmolol)
Hypertensive emergency with acute or chronic renal failure	Nicardipine or fenoldopam
Hypertensive encephalopathy	Nicardipine, labetalol, fenoldopam Note: the blood pressure should not be lowered by more than 25%
Pre-eclampsia / eclampsia	Labetalol or nicardipine
Sympathetic crisis / cocaine overdose	Benzodiazepine + (verapamil, diltiazem, or nicardipine) Note: Beta blockers should NOT be administered alone to prevent un-opposed alpha-adrenergic stimulation
Cerebrovascular accident	Nicardipine, labetalol, fenoldopam, or clevidipine Note: An expert's judgement is required to determine if the blood pressure should be lowered.
Withdrawal of antihypertensive therapy e.g. clonidine or propanolol	Re-administer the discontinued drug; phentolamine, nitroprusside, or labetalol, if necessary

Dos

• Hypertensive emergencies are best managed with a continuous infusion of short-acting titratable antihypertensive agents.
• Avoid sublingual and intramuscular routes of drug administration due to their unpredictable pharmacodynamics.
• Assess the patient' volume status before initiating intravenous vasodilators to prevent or minimize a substancial fall in blood pressure.

Don'ts

• Don't consider nifedipine, nitroglycerin and hydralazine as first-line therapies in the management of hypertensive crises due to their potential toxicities and adverse effects.
• Don't use intramuscular or sublingual antihypertensive medications in the case of hypertensive emergency.
• Don't use rapid acting antihypertensive if the patient is not in an ICU setting.