Management of Acute Hypertension-

Acute Hypertension- Management of

Assessment

The width of the bladder in the BP cuff should be at least two thirds the length of the upper arm and completely encircle the upper arm. Inadequate bladder size can result in a falsely elevated reading.

Patients with BP over the 95th percentile require further evaluation.

Hypertensive urgency, much more common in children, is significant elevation in BP without accompanying end-organ damage.

Symptoms include headache, blurred vision, and nausea.

Hypertensive emergency is defined as elevation of both systolic and diastolic BP with acute end-organ damage (e.g., cerebral infarction, pulmonary edema, hypertensive encephalopathy, and cerebral hemorrhage).

It is important to note that the clinical differentiation between hypertensive urgencies and hypertensive emergencies depends on end-organ damage rather than BP measurement.

Evaluate for underlying etiology:

Medication/ingestion, cardiovascular, renovascular, renal parenchymal, endocrine, or CNS. Rule out hypertension secondary to elevated intracranial pressure (ICP) before lowering BP.

A physical examination should include

measurement of four-extremity BP

funduscopy (papilledema, hemorrhage, exudate

visual acuity

thyroid examination

evidence for congestive heart failure (tachycardia, gallop rhythm, hepatomegaly, edema),

abdominal examination (mass, bruit),

neurologic examination

evidence of virilization,

cushingoid effect.

diagnostic evaluation

urinalysis

blood urea nitrogen (BUN), creatinine

electrolytes

chest radiograph,

ECG.

Consider obtaining renin level before beginning antihypertensive therapy.

a toxicology screen, thyroid/adrenal testing, urine catecholamines,

renal Doppler ultrasound, and computed tomography (CT) of the head as indicated.

Management

Hypertensive emergency:

IV line

monitor,

arterial line for continuous BP monitoring

Seek consultation with a nephrologist or cardiologist

The goal is to lower BP promptly but gradually to preserve cerebral autoregulation.

The mean arterial pressure (MAP) (where MAP = 1/3 SBP + 2/3 DBP) should be lowered by one third of the planned reduction over 6 hours,

 an additional third over the next 24 to 36 hours,

the final third over the next 48 hours.

After elevated ICP is ruled out, do not delay treatment because of diagnostic evaluation

Note that the use of IV hydralazine may result in severe, prolonged, and uncontrollable hypotension and is not recommended.

Hypertensive urgency:

Aim to lower MAP by 20% over 1 hour and return to baseline levels over 24 to 48 hours.

An oral route may be adequate.

 Observe in the emergency department for 4 to 6 hours.

follow-up is mandatory.

use of sublingual nifedipine = can result in a precipitous, uncontrolled fall in BP.

MEDICATIONS FOR HYPERTENSIVE EMERGENCY

Drug	Onset	(Route)	Duration  Interval to Repeat or Increase Dose	Comments
Diazoxide (arteriole vasodilator)	1-5 min	(IV)	Variable (2-12 hr)  15-30 min	May cause edema, hyperglycemia
INFUSIONS
Nitroprusside (arteriole and venous vasodilator)	<30 sec	(IV)	Very short  30-60 min	Requires ICU setting; follow thiocyanate level
Labetalol (α-, β-blocker)	1-5 min	(IV)	Variable, about 6 hr  10 min	May require ICU setting
Nifidepine (calcium channel blocker)	1 min	Sub lingual	3 hr  15 min	May cause edema, headache, nausea/vomiting ICU, Intensive care unit.

MEDICATIONS FOR HYPERTENSIVE URGENCY

Drug                 Onset   (Route)             Duration  Interval to      Repeat  Comments 

Enalaprilat        15 min (IV)                  12-24 hr  8-24 hr         May cause hyperkalemia,

hypoglycemia

Minoxidil          30 min (PO)                 2-5 days  4-8 hr           Contraindicated in

pheochromocytoma