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]

Definitions

• Hypertensive urgency is the severe elevation in the blood pressure (systolic blood pressure>160 mmHg, or diastolic blood pressure>100 mmHg) with no or minimal evidence of acute target organ damage.

• Hypertensive emergency is the severe elevation in the blood pressure (systolic blood pressure>180 mmHg, or diastolic blood pressure>120 mmHg) complicated acute target organ dysfunction, such as hypertensive encephalopathy, intracerebral hemorrhage and acute myocardial infarction.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Hypertensive crisis is a life-threatening condition and must be treated as such irrespective of the cause.

Common Causes

• Antihypertensives 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 HTN ❑ 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 (NB - Treat the patient and not the BP)

Hypertensive urgency

Admit to ICU Close BP monitoring ↓ Intra-arterial BP monitoring in severely-ill patients ↓ Assess volume status - IV N/S if volume depleted to prevent precipitous fall in BP following administration of antihypertensives ↓ Commence continuous infusion of short acting IV antihypertensives based on patient's end organ damage ↓ Change IV meds to oral when BP is stable NB - Not more than 25% reduction in BP within the 1st hour; when BP 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

Outpatient/Admit for observation Oral antihypertensives Clinical surveillance within the first few hours of commencing medications NB - Gradual BP reduction over 24 - 48 hours

Management of specific hypertensive emergencies

Failure to control the blood pressure ❑ Consider combination of antihypertensives

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

Intravenous Antihypertensives

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 Antihypertensives

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 BP to 120 mmHg within 20 minutes with protection against reflex tachycardia.
Acute pulmonary edema/systolic dysfunction	NTG + (Nicardipine or, fenoldopam, or nitroprusside) + loop diuretic
Acute pulmonary edema/diastolic dysfunction	Low-dose NTG + (esmolol, metoprolol, labetalol, or verapamil) + loop diuretic
Acute coronary syndrome	NTG + (labetalol or esmolol)
Hypertensive emergency with ARF/CRF	Nicardipine or fenoldopam
Hypertensive encephalopathy	Nicardipine, labetalol, fenoldopam Note: The BP 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 BP 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.
• Both sublingual and intramuscular routes of drug administration should be avoided due to their unpredictable pharmacodynamics.
• Assess patients' volume status before commencing intravenous vasodilators to prevent/minimize precipitous 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.