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]

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 target organ damage.

• Hypertensive emergency is the severe elevation in the blood pressure, usually greater than 180/120 mmHg, complicated by evidence of impending or progressive 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 causes.

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, altered/LOC, difficulty speaking, altered level of consciousness ❑ Eyes - pain, blurred/loss of vision ❑ Cardiopulmonary - chest pain, dyspnea ❑ Renal - hematuria, proteinuria, reduced urinary output ❑ Others - nausea/vomiting, severe anxiety, nosebleeds

Evaluate the patient for acute organ damage: ❑ History PMH especially HTN Medications (prescription or over the counter) - dosages, compliance Recreational drug use - methamphetamine, cocaine, phencyclidine ❑ Physical Blood pessure - both arms Fundoscopy - papilledema, exudates, hemorrhages Neuro exam - mental status, focal neurological deficits Cardiopulmonary - signs of pulmonary edema, murmurs, gallops Abdomen - pulsatile masses, tenderness, bruits Limbs - peripheral pulses

Order Labs: ❑ CBC ❑ BMP + Mg + PO4 ❑ Serum uric acid ❑ FLP ❑ FBS ❑ Urinalysis/culture ❑ Urine electrolytes, creatinine, protein ❑ Chest X-ray ❑ EKG, ECHO ❑ Renal USS + doppler

Further work-up: ❑ TSH, free T3, free T4 ❑ Serum cortisol ❑ Serum aldosterone ❑ Serum renin levels ❑ HbA1C ❑ 24-hr urinary catecholamine & metanephrine levels ❑ Serum parathyroid hormone levels ❑ Urine and serum toxicology screen ❑ Urine pregnancy test ❑ CT/MRI ❑ DMSA/DTPA scans (renal scars) ❑ ANA/ESR/CRP/anti-dsDNA/anti-smith/rheumatoid factor/p-ANCA/c-ANCA

Evidence of end organ damage (any of the symptoms above)

YES

NO

Hypertensive emergency (NB - Treat the patient and not the BP)

Hypertensive urgency

Admit 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 IV antihypertensives based on patient's symptom ↓ 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

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

Worsening blood pressure

Good control Review old/start new medication Modify risk factors Close follow-up

Intravenous Antihypertensives

Drug	Dose	Onset of action	Duration of action	Special indication	Avoid use
Clevidipine	1 to 2 mg/h as IV infusion, max 16 mg/h	2-4 mins	5-15 mins	Most HE	-----
Enalaprilat	1.25–5 mg every 6 hrs IV	15–30	6–12 hrs	Acute left ventricular failure	AMI, renal impairment, pregnancy. No benefit in HE.
Fenoldopam	0.1–0.3 µg/kg per min IV infusion	<5 min	30 min	Most HE + renal insufficiency	Glaucoma or ↑ICP
Hydralazine	10–20 mg IV	10–20 min IV	1–4 hrs	Eclampsia; although labetalol or nicardipine is preferred	This should generally be avoided due to its unpredictable pharmacodynamics
Nicardipine	5–15 mg/h IV	5–10 min	1.5 - ≥4 hrs	Most HE esp post-op hypertension, aortic dissection & pregnancy	Acute heart failure. Caution with cirrhotics & coronary ischemia
Nitroglycerin	5–100 µg/min as IV infusion	2–5 min	5–10 min	Coronary ischemia, cardiogenic pulmonary edema	Not used for most HE
Nitroprusside	0.25–10 µg/kg/min as IV infusion	Immediate	1–2 min	Most HE; should be avoided due to its toxicity (cyanide toxicity)	Caution with ↑ICP, AMI, CAD, CVA, renal or hepatic impairment.
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	1–2 min	10–30 min	Aortic dissection, perioperative (to reduce reflex tachycardia)	Acute decompensated heart failure
Labetalol	20–80 mg IV bolus every 10 min 0.5–2.0 mg/min IV infusion	5–10 min	3–6 hrs	Most HE; used in combination with vasodilators to reduces reflex tachycardia	Acute decompensated heart failure, heart block, asthma, pheochromocytoma
Phentolamine	5–15 mg IV bolus	1–2 min	10–30 min	Catecholamine excess

• HE - Hypertensive emergencies

Oral Antihypertensives

Drug	Dose	Onset of action	Duration of action
Captopril	12.5 to 25 mg PO or SL, repeat as needed. max dose - 50 mg PO	5-15 mins	2-6 hrs
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	15-30 mins	2-8 hrs
Labetalol	200 mg PO, then 200 mg/hr until desired effect. Max dose - 1200 mg	2 hrs	4 hrs

• 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.