Hypertensive Emergencies

Say what?

Hypertensive emergency has no universally accepted definition. Actual numbers are often used to define hypertensive emergency, though strictly speaking a hypertensive emergency is any elevation in blood pressure in the presence of end-organ dysfunction.1,2,3

Aggressively treating severe asymptomatic hypertension (very high blood pressure without clear end organ damage) is not indicated, not supported by the literature and dangerous. First, do no harm.

No end-organ damage ≠ HTN emergency

Pathophys alert: the mechanism of HTN emergency is poorly understood but it generally results from an abrupt rise in systemic vascular resistance, direct endothelial injury, and a loss of the body’s ability to autoregulate flow in vital organs. This leads to a continued increase in BPs and end organ damage. 2,4,5 Furthermore extremes of pressure result in activation of the renin-angiotensin-aldosterone axis. This leads to further vasoconstrictor release and elevations in BP. Finally, many patients undergo a pressure-induced natriuresis. The resulting intravascular volume loss causes further mediator release that elevates BP.

Your patient may report (from most to least common) 6:

  • Dyspnea (up to 30%)
  • Chest pain
  • Headache
  • Altered Mental Status
  • Limb weakness or sensory changes
  • Seizures (eclampsia)

You should ask about:

  • History of hypertension
  • Compliance with medication
  • Illicit drug use
  • Pregnancy
  • Kidney disease

On physical examination you should look for: 

  • Changes in mental status
  • Focal neurological abnormalities
  • Papilledema
  • Rales
  • JVD/S3
  • Asymmetric blood pressures between limbs

Is this really it?

If you patient has an elevated blood pressure in the setting of end organ dysfunction, then yes, it is.

If there are no clear signs of end organ damage, then no, it isn’t.

What tests does my patient need?

When evaluating your hypertensive patient it is imperative to make the distinction between a patient with symptomatic and asymptomatic hypertension. The recommendations below are for symptomatic patients only. Testing is mostly based on your patient’s presentation.

Labs: obtain a creatinine to assess for renal failure. A troponin and BNP are indicated if your patient has signs and symptoms consistent with cardiac ischemia or pulmonary edema.

Urine: perform a urinalysis to assess for proteinuria, indicating renal failure. If a pheochromocytoma is suspected obtain urine metanephrines. Obtain a toxicology screen if illicit drug use is suspected.

ECG: obtain if your patient has chest pain, shortness of breath, or signs and symptoms of pulmonary edema. Assess for ischemic changes.

Chest X-ray: indicated if pulmonary edema is suspected.

CT/MRI-scan: a CT-scan of the chest is indicated if an aortic dissection is suspected. CT scan of the brain should be obtained in a patient who has a history and/or physical examination consistent with an ischemic or hemorrhagic stroke. An MRI is more sensitive than a CT-scan for detecting changes consistent with hypertensive encephalopathy.

Is there a cure, doc?

For HTN emergencies, first, do no harm. Traditionally, a reduction of your patient’s mean arterial pressure (MAP) of no more than 20-25% in the first hour of treatment has been recommended. Several studies have indicated that we often do not do this well, and that we drop our patient’s blood pressure too rapidly in the emergency department. 7 Rapid lowering of the blood pressure poses your patient at risk of ischemic events (occurring in up to 5% of patients with rapid blood pressure reduction), and should be avoided at all cost. Aim for a reduction of 15-20% in the first hour, and no more than 25% in first 2 hours. It is important to monitor your patient’s blood pressure very closely. For that reason, an arterial line is highly recommended in HTN emergency. 6,9,10

What is the best route of drug administration?

A continuous, short acting, titratable intravenous agent is indicated for initial treatment. A continuous infusion is likely to achieve more predictable blood pressure control compared to repeated doses of antihypertensives. Oral and transdermal antihypertensives are not indicated in hypertensive emergency. These agents have a high failure rate and cannot easily be reversed.

Which agent should I use?

There are few studies with head to head comparison of agents in HTN emergency. One 2011 study suggested nicardipine, when compared to labetalol, may be superior in time to BP reduction, less adverse events and less need for use of additional agents. 11 Of note: most of the studies comparing nicardipine to labetolol are manufacturer sponsored. None of these studies report patient centered outcome differences (i.e. mortality benefit).

Consider the agents below depending on the specific end organ damage: 7,10,11

Medication End Organ Damage Pearls
Nicardipine Aortic Dissection
Renal Failure
HTN encephalopathy
Hemorrhagic or ischemic stroke
If used in dissection, must give beta blocker first
Clevidipine Aortic Dissection
Renal Failure
HTN Encephalopathy
Hemorrhagic or ischemic stroke
Fast onset and shorter half life than nicardipine makes, hence, very titratable but not available in many institutions
Labetalol Aortic Dissection
Pre-eclampsia and eclampsia
Hemorrhagic or ischemic strokes
Safe in pregnancy
Can be used as signal agent in aortic dissection
Nitroglycerin Acute Pulmonary Edema
Acute Coronary Syndrome
May use sublingual or topical forms until IV access established
Esmolol Aortic Dissection Should be used before vasodilator in dissection
Bolus initially and then begin continuous infusion
Phentolamine Cocaine or amphetamine intoxication
Pheochromocytoma
Secondary treatment with cocaine or amphetamines after trial of benzodiazepines
Fenoldopam Acute Renal Failure
Furosemide Acute Pulmonary Edema Not a first line agent as patients are generally hypovolemic; furosemide is also slow to work so should be used as an adjunctive agent

 

Additional Treatment Pearls:

  • Aortic dissection: if your patient has aortic dissection, rapidly lower the heart rate to approximately 60 beats per minute to help prevent reflex tachycardia. Once the heart rate is controlled, rapidly lower the SBP to < 120 mm Hg. Aortic dissection is the one HTN emergency where the rule of a 15-20% reduction in MAP during the first hour does not apply.
  • There is no clear data to prove that aggressive blood pressure lowering reduces hematoma expansion if your patient has a intracerebral hemorrhage, however, early high blood pressures are associated with mortality. 12 Therefore, aggressive blood pressure management should be considered, and recent data indicated that this may be safe. 13,14,15
  • In stroke patients, blood pressure targets are guided by stroke subtype and presenting blood pressure. 12 Start with a MAP reduction of 15-20% in the first hour in the ED.

Miller table stroke SBP

  • Eclampsia: give intravenous magnesium sulfate combined with labetolol. Definitive treatment is delivery of fetus.
  • A headache does not equal hypertensive encephalopathy. Hypertensive encephalopathy is diagnosed after a CT scan of the brain ruled out a bleed or stroke. 9
  • Give IVF fluids – most patients with hypertensive emergency are intravascularly depleted. Providing IV fluids can help prevent dropped blood pressures after initiation of antihypertensives. 16,17

FOAM under pressure: blow of some steam with continued reading/listening

Beginner

Intermediate

Advanced

References

1. Chobanian AV, Bakris LG, et al. Seventh report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure. Hypertension. 2003; 42:1206-52.

2. Kessler CS and Joudeh Y. Evaluation and treatment of severe asymptomatic hypertension. AFP. 2010; 81: 470-476.

3. Wolfe SJ, Lo B, et al. Clinical policy: critical issues in the evaluation and management of adult patients in the emergency department with asymptomatic elevated blood pressure. Ann Em Med. 2013; 62: 59-64.

4. Vaughan CJ and Delanty N. Hypertensive emergencies. The Lancet. 2000; 356: 411-7.

5. Papadopoulos DP, Mourouzis I, et al. Hypertension crisis. Blood Pressure. 2010; 19: 328-36.

6. Marik PE and Rivera R. Hypertensive emergencies: an update. Current Opinion in Critical Care. 2011; 17: 569-580.

7. Brooks TWA, Finch CK, Lobo BL, et al. Blood pressure management in acute hypertensive emergency. Am J Helath-Syst Pharm. 2007; 64: 2579-2582.

8. Emergency Medicine Updates – Hypertension and the Emergency Physician

9. Johnson W, Nguyen M, Patel R. Hypertension in the emergency department. Cardiol Clin. 2012; 30: 533-543.

10. Flanigan JS and Vitberg D. Hypertensive emergency and severe hypertension: what to treat, who to treat, and how to treat. Med Clin N AM. 2006;90:439-451.

11. Peacock WF, Varon J, et al. CLUE: a randomized comparative effectiveness trial of IV nicardipine versus labetalol use in the emergency department. Critical Care. 2011; 15: R157-64.

12. Miller J, Kinni H, Lewandowski C, Nowak R, Levy P. Management of hypertension in stroke. Ann Emerg Med. 2014 Sep;64(3):248-55.

13. Zazulia, A.R., Diringer, M.N., Videen, T.O. et al. Hypoperfusion without ischemia surrounding acute intracerebral hemorrhage. J Cereb Blood Flow Metab. 2001; 21: 804–810

14. Anderson CS, Heeley EH, Huang Y, et al. Rapid blood-pressure lowering in patients with acute intacerebral hemorrhage. NEJM. 2013; 368:2355-2365.

15. Anderson CS, Huang Y, Wang JG, et al. Intensive blood pressure reduction in acute cerebral haemorrhage trail (INTERACT): a randomized pilot trial. Lancet Neurol. 2008; 7: 391-9.

16. Marik PE, Rivera R. Hypertensive emergencies: an update. Curr Opin Crit Care 2011; 17:569-80.

17. UMEM Education Pearls- Hypertensive Emergencies

 

Written by: Phil Magidson, M.D., M.P.H. | Edited by: Maite Huis in ‘t Veld, M.D. | Peer reviewed by: Michael Winters | November 9th, 2014

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3 thoughts on “Hypertensive Emergencies

  1. Excellent content.
    I would like to empathize the major challenge deciding if the current symptoms are caused or not by HTN; after that he management is straightforward.

    Like

  2. Robert says:

    “Aggressively treating severe asymptomatic hypertension (very high blood pressure without clear end organ damage) is not indicated, not supported by the literature and dangerous. First, do no harm.”

    A little story about this. I recently (maybe — usual disclaimers, details changed) had a 97yo man with a ground level fall I admitted to the hospital with a hip fracture. His blood pressure was in the 170s — something I did not care about one whit. When you have been on this earth for almost a century, you can have any blood pressure you damn well please, as long as it’s not causing you problems. He also had a murmur — harsh and audible over over the chest.

    Well, you can imagine what happened next. The hospitalist gave him labetolol 10mg, just to tune him up a little — and he coded. Full on PEA arrest. Fortunately this was psuedoPEA and epi and compressions brought him back within a few minutes. The lessons, of course, are:

    1. Even in 2014, your exam matters.
    2. People with aortic stenosis are preload dependent.
    3. Beta blockers reduce preload
    4. Hypertension is like an alligator. If it will leave you alone (in the ED), leave it alone.

    Like

  3. […] a great overview of hypertensive emergencies from S.O.A.P. […]

    Like

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