University of Toronto EM Residency program director, Joel Yaphe and cardiovascular EM researcher, Clare Atzema discuss the guidelines, controversies, pearls & pitfalls of Asymptomatic Hypertension in the ED. The literature is thin in this area, and there are many controversies: Does an elevated BP measured in the ED represent true essential hypertension? Do these patients need to be worked up? Are they at risk of serious morbidity and mortality? Should we treat these patients in the ED with antihypertensives? Should we send them home on antihypertensives? and many more……

Written summary and blog post by Claire Heslop, edited by Anton Helman, February 2014

What is a Hypertensive Emergency?

When seeing a patient with high BP, our experts recommend the following questions be used to differentiate true hypertensive emergencies from less urgent presentations:

1) Is there acute end-organ dysfunction and/or damage?
2) Is the dysfunction attributable to the elevated blood pressure (or will the elevated BP likely to make the dysfunction worse)?
3) Is altering the BP necessary to improve the organ dysfunction?

If the answer is “Yes”, this may be a hypertensive emergency. If not, these patients with high BP can be treated on an individualized basis, less aggressively.

Does triage BP correlate with outpatient HTN?

For patients who present at triage with a high BP, an elevated second measurement one hour later correlates highly with actual outpatient hypertension (1), and does not correlate with the patient’s anxiety and/or pain (2).

New Hypertension Target Guidelines for older patients:

The new JNC guidelines suggest that overaggressive BP treatment in the elderly may not be beneficial. Adivise outpatient BP targets for patients over 60 years old should be below 150/90 (3).

Canadian Hypertension Education Program (CHEP) 2013 guidelines suggest these targets for
patients over 80 years of age.

History for asymptomatic hypertensive patients

Ask a few key questions to identify possible causes of hypertension:

1) does the patient have a history of hypertension?

2) are they compliant with their medications? Any medication changes?

3) do they have a recent trigger (high salt diet, alcohol use, NSAID use, steroids, cold meds)

4) are they pregnant or are they postpartum?

5) when was the last time they had their BP checked (and is this chronic hypertension that does not require acute management)?

Take an organized approach to screening, by organ system, although symptoms are poorly related to BP (6).

CNS: Headache, nausea, vomiting, confusion, visual changes, neurologic localizing symptoms

Cardiac: chest pain, shortness of breath, ankle swelling, orthopnea, PND

Renal: polyuria, nocturia, hematuria

Secondary causes should be searched in patients who are younger (<30), and have very high BP (renal artery stenosis). Also think about Cushing syndrome, hyperaldosteronism, pheochromocytoma, etc.

Physical Exam for patients presenting with elevated blood pressure

Look for end organ damage and/or dysfunction.

Focus based on presenting symptoms (i.e. careful neuro exam in patients with HTN and headache, or for signs of dissection in patients with high BP and chest pain).

Always look at the fundi for acute retinal hemorrhages, exudates, papilledema, as these signs indicate a hypertensive emergency. Retinal nerve diameter can also be assessed by bedside U/S, to look for raised ICP.

Check for physical signs of secondary causes (i.e. striae for Cushings).

What diagnostic tests should we do for patients with asymptomatic hypertension?

Recent ACEP guidelines suggest no workup is needed. However, as studies show a 6– 7% rate of clinically meaningful findings (4), consider screening tests on select patients. Consider a urine dip, which is 80–90% sensitive for renal dysfunction (5).

Follow with renal bloodwork if abnormal (proteinuria or hematuria). When screening patients unlikely to have close follow-up, consider starting with renal bloodwork, to avoid missing that 10–20% who will have a normal urine.

If the hypertension may have been chronic, consider an ECG to look for LVH (may require outpatient Echo).

Treating Asymptomatic Hypertension

Should we treat patients with asymptomatic hypertension in the ED?

Although there is a paucity of evidence for treatment of hypertension in the ED affecting shortterm outcome (7), reducing BP will reduce risk of morbidity and mortality over the longer term (7).

How low and how fast should you go?

Do not drop BP rapidly, as it alters cerebral perfusion and puts patients at risk for organ underperfusion (i.e. ischemic stroke), especially if their blood pressure elevation has been chronic.
The ACEP Clinical Policy states there is no need to immediately reduce an asymptomatic patient with high blood pressure (8,9). They can instead be referred back to their family physician for BP management (10).

Is there a target BP for asymptomatic HTN?

The Canadian Emergency Medicine Cardiac Research and Education Group (EMREG) guidelines advise ED physicians to consider beginning antihypertensive therapy for patients with BP of >180/110, and to initiate treatment if BP > 200/130 (11). These recommendations are based on limited evidence. Furthermore, there are no guidelines for the exact target BP that needs to be achieved before discharge.

emcases-update Update 2015: Study in Academic Emergency Medicine suggests that prescription of anti-hypertensives in the ED may be safe and effective, at least in the short-term, for patients with asymptomatic hypertension. Abstract

Which drug is best for treatment of asymptomatic hypertension?

Most patients can be started on a thiazide, an ACE-inhibitor or ARB, or a calcium-channel blocker (CCB) (12).
Exceptions:

1. For patients with coronary artery disease, a B-blocker is first line.

2. For black patients, cardiac risk reduction is best achieved with a thiazide or a CCB.

** Remember to think about the contraindications for each agent. ACEi or ARBs are contraindicated in patients at risk for hyperkalemia. Do not use thiazides in patients with gout, and avoid B-blockers in patients with COPD or asthma. **

Follow up for patients with asymptomatic hypertension

Although there is a paucity of evidence, most clinicians recommend follow up within 7 days, or more urgently for patients with severe hypertension or comorbidities.

CHEP guidelines are more liberal; they advise BP be rechecked within 1 month (13).

However, patients started on an ACE or an ARB should follow up sooner, and have their electrolytes checked within 1 week.

For an excellent basic review for medical students and residents of asymptomatic hypertension visit EM Basic.

Now Test Your Knowledge

At about 60 minutes, the ED blood pressure will correlate well their outpatient serial BP measurements, and usually represents true essential hypertension if elevated despite any anxiety or pain they might be experiencing (1,2)
Recent ACEP guidelines suggest no workup is necessary.

However, as studies show a 6-7% rate of clinically meaningful findings (4), Dr. Yaphe & Dr. Atzema recommend to consider screening tests on select patients.

A urine dip, which is 80-90% sensitive for renal dysfunction (5), should be considered to screen for renal disease in high disease burden communities, follwed by creatinine if significant proteinuria/hematuria is found.

For patient’s suspected of chronic hypertension, consider an ECG to look for LVH which may mandate an outpatient echocardiogram

JNC: 1. Outpatient BP targets for patients >60 years <150/90 2. If antihypertensives are started in the ED, most patients can be started on a thiazide or an ACE-inhibitor or ARB or a calcium channel blocker (CCB) with the exception of patients with coronary artery disease who should be started on a B-blocker and black patients who should be started on a thiazide or a CCB (3)

CHEP: 1. Outpaient BP targets for patients >80 years <150/90  2. Consider beginning antihypertensive therapy for patient with BP >180/10 and initiate treatment if BP>200/130. *note this recommendation is based on limited evidence 3. Follow up outpatient BP is recommended within one month for patients found to be hypertensive in the ED.

Although there is a paucity of evidence for the treatment of hypertension in the ED affecting short-term outcomes, reducing BP will reduce risk of morbidity and mortality in long-term outcomes (7).

Symptoms such as mild headache and vague dizziness that are deemed to be benign in nature do not correlate with the degree of blood pressure elevation and so these patients should be approached in the same manner as asymptomatic patients (6).

Do not drop the BP rapidly with potent short-acting antihypertensives like clonidine or hydralazine in asymptomatic chronic hypertensive patients, as this may alter their cerebral perfusion such that they underperfuse the watershed areas of the brain and cause ishemia.

This recommendation is consistent with the newest ACEP guidelines (8,9). There are no guidelines or expert recommendations for an exact target BP that needs to be achieved before discharge.

Recent ACEP guidelines suggest no workup is necessary. However, as studies show a 6-7% rate of clinically meaningful findings (4), Dr. Yaphe & Dr. Atzema recommend to consider screening tests on select patients with asymptomatic hypertension.

A urine dip, which is 80-90% sensitive for renal dysfunction (5), should be considered to screen for renal disease in high disease burden communities, followed by creatinine if significant proteinuria/hematuria is found.

For patient’s suspected of chronic hypertension, consider an ECG to look for LVH which may mandate an outpatient echocardiogram.

Although there is a paucity of evidence for the treatment of hypertension in the ED affecting short-term outcomes, reducing BP will reduce risk of morbidity and mortality in long-term outcomes (7).

Symptoms such as mild headache and vague dizziness that are deemed to be benign in nature do not correlate with the degree of blood pressure elevation and so these patients should be approached in the same manner as asymptomatic patients (6).

Do not drop the BP rapidly with potent short-acting antihypertensives like clonidine or hydralazine in asymptomatic chronic hypertensive patients, as this may alter their cerebral perfusion such that they underperfuse the watershed areas of the brain and cause ishemia. This recommendation is consistent with the newest ACEP guidelines (8,9).

There are no guidelines or expert recommendations for an exact target BP that needs to be achieved before discharge.

 

Dr. Helman, Dr. Yaphe and Dr. Atzema have no conflicts of interest to declare.

References

  1. Dieterle T, Schuurmans MM, Strobel W, et al. Moderate‐to‐severe blood pressure elevation at ED entry. Hypertension or normotension? Am J Emerg Med. 2005;23:474‐479
  2. Tanabe P, Persell SD, Adams, JG, et al. Increased blood pressure in the emergency department: pain, anxiety or undiagnosed hypertension? Ann Emerg Med. 2008;51:221-229.
  3. 2014 Evidence-Based Guildeline for the Management of High Blood Pressure in Adults: Report from the panel members appointed to the eighth Joint National Committee (JNC 8). JAMA. doi:10.1001/jama.2013.284427. Published online December 18, 2013
  4. Karras DJ, et al: Utility of routine testing for patients with asymptomatic severe blood pressure elevation in the emergency department. Ann Emerg Med  2008; 51:231.
  5. Karras DJ, Heilpern KL, Riley LJ, Hughes L, Gaughan JP. Urine dipstick as a screening test for serum creatinine elevation in emergency department patients with severe hypertension. Acad Emerg Med. 2002;9(1):27-34.
  6. Karras DJ, et al: Lack of relationship between hypertension-associated symptoms and blood pressure in hypertensive ED patients. Am J Emerg Med 2005; 23:106.
  7. Veterans Admin. JAMA. 1967; 202;116
  8. Wolf SJ. et al. Ann Emerg Med. 2013;62-59.
  9. Levy P, et al: Acute blood pressure reduction and outcomes in asymptomatic hypertension: A retrospective cohort study. Ann Emerg Med 2011; 58:S238.
  10. Levy P, et al: Acute blood pressure reduction and outcomes in asymptomatic hypertension: A retrospective cohort study. Ann Emerg Med 2011; 58:S238.
  11. Slovis CM. Reddi AS. Ann Emerg Med. 2008;51:S7
  12. Lin, M. Paucis Verbis. First line treatment for hypertension. academiclifeinem.com/