Monday, March 30, 2015

Think before pulling the trigger: HTN Urgency/Emergency

For this week we have a quick one, on Hypertension (Symptomatic/Asymptomatic) Management in the ED looking at HTN Emergency/ HTN urgency.

Asymptomatic HTN aka "HTN Urgency"

We get really worried about the numbers when we come across such patients with markedly elevated pressures who are asymptomatic! Well, You will just do fine if you perform a good history and physical on them, give them some time and recheck BP after sometime. Don't push them to the ICU just because of those numbers.

Lets look at ACEP 2013 policy on Asymptomatic HTN, They looked at 2 specific questions:
1. In ED patients with asymptomatic elevated blood pressure, does screening for target organ injury reduce rates of adverse outcomes?

(1) In ED patients with asymptomatic markedly elevated blood pressure, routine screening for acute target organ injury (e.g., creatinine, urinalysis, ECG) is not required.
(2) In select patient populations (eg, poor follow-up), screening for an elevated serum creatinine level may identify kidney injury that affects disposition.

2. In patients with asymptomatic markedly elevated blood pressure, does ED medical intervention reduce rates of adverse outcomes?

1) In patients with asymptomatic markedly elevated blood pressure, routine ED medical intervention is not required.
(2) In select patient populations (eg, poor follow-up), emergency physicians may treat markedly elevated blood pressure in the ED and/or initiate therapy for long-term control. [Consensus recommendation]
(3) Patients with asymptomatic markedly elevated blood pressure should be referred for outpatient follow-up. [Consensus recommendation] 

Sometimes doing nothing is adequate as about 1/3 of patients had lowering of BP in the ED with no medical intervention. So, when dealing with a asymptomatic hypertensive next time, don't get worried with the numbers, treat only if the patient is symptomatic. And it also equally important to educate them about the harms of rapidly lowering the BP. 

Symptomatic HTN

Hypertensive emergency is any form of acute end-organ dysfunction.
End organ dysfunction includes ARF, Eclampsia, Heart Failure, Dissection, ACS, CVA, Encephalopathy. (Don't look at specific numbers to diagnose HTN emergency!)

If you have someone with symptomatic HTN (SOB, Chest Pain, AMS, headache, focal deficits), first and foremost - try to find out the cause of elevated BP:

  1. Ask them about medication compliance
  2. Substance abuse (cocaine, amphetamines)
  3. Symptoms related to Pheo, Thyroid, Renal Artery Stenosis, Coarctation of Aorta.

This subset of patients needs aggressive reduction of BP with IV medications (reduce MAP by 20-25% over 1 hour). Majority of them are volume depleted, so give them some IV fluids too.

Now the question is, which should be our drug of choice ?
It depends a lot on your history and working diagnosis because anti HTN meds work best if they are chosen with respect to the cause of elevated blood pressure. I do see people grabbing NTG for undifferentiated hypertension (regardless of the cause/symptoms), using venodilating wimpy doses, with which I don't really agree. 

DOC is based on your diagnosis, for instance, use:
  • NTG - Acute Pulmonary Edema
  • Labetalol/Nicardipine - CVA
  • Beta blockers - Dissection
  • Eclampsia - Mg/ labetalol - Eclampsia

Key Points:
  1. Don't get worried with numbers, treat only if the patient is symptomatic. Asymptomatic HTN goes home with good follow up/discharge instructions.
  2. High BP + end organ damage is HTN emergency, again don't look at specific numbers to call it HTN emergency.
  3. Reduce MAP by 20-25% in the first hour with titrable IV meds (Exception dissection, eclampsia where you need to get down as quickly as possible)
  4. Most of them are fluid depleted and need IV fluids, which also prevents the sudden drop in pressures after commencing IV therapy.
  5. NTG drip is not the answer to everything! 

For further reading:

  1.  Wolf SJ, Lo B, Shih RD, et al. Clinical policy: critical issues in the evaluation and management of adult patients in the emergency department with asymptomatic elevated blood pressure. Ann Emerg Med. 2013; 62: 59-68.
  2. Marik PE, Rivera R. Hypertensive emergencies: an update. Current Opinion in Critical Care 2011;17(6):569-80. 

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