GENERAL THERAPIES / ARTERIAL HYPERTENSION

Hypertensive crisis

David Goldemund M.D.
Updated on 20/01/2024, published on 03/11/2022

Definition

  • a hypertensive crisis is a medical emergency characterized by a sudden and severe elevation in blood pressure
    • the cut-off values are not universally established and are arbitrary (usually > 180/120 mmHg)
    • the rate of BP elevation seems to be more important than its absolute value
  • the term crisis is abandoned in favor of the following terms, differentiated by the presence of a target organ lesion:
    • hypertensive urgency – no target-organs damage
    • hypertensive emergency – acute target-organs complications are present (heart, kidneys, brain, eyes)
  • hypertensive crisis has a mortality rate of up to 7% (Katz, 2009)

Etiology

  • decompensation of chronic hypertension
    • most commonly caused by sudden discontinuation of antihypertensive medication or drug interactions
    • periprocedural
    • acute stroke (which may be a cause or result of uncontrolled hypertension)
  • secondary hypertension
    • pheochromocytoma
    • preeclampsia/eclampsia
    • abuse of sympathomimetic drugs (amphetamine, LSD, cocaine)

Clinical presentation

  • cerebrovascular
    • hypertensive encephalopathy (confusion, headaches, nausea/vomiting, visual disturbances, seizures)
      • symptoms of hypertensive encephalopathy resolve after blood pressure is lowered and  autoregulation of cerebral blood flow (CBF) is restored
    • posterior reversible encephalopathy syndrome (PRES)
    • intracerebral hemorrhage (focal symptoms)
    • subarachnoid hemorrhage (headache, meningeal syndrome)
  • cardiovascular (chest pain, shortness of breath)
    • acute left-sided heart failure (dyspnea, pulmonary edema)
    • acute MI/unstable angina
    • acute aortic dissection (acute and severe chest or back pain)
  • renal
    • acute renal failure
  • eye symptoms
    • hemorrhages, exudates, or disc edema (signs of hypertensive retinopathy grade III or IV)

Diagnostic evaluation

  • serial BP measurement or continuous BP monitoring
    • start by measuring BP in both arms (to exclude aortic dissection or coarctation, subclavian artery stenosis)
    • if aortic dissection is suspected, also measure BP in the lower limbs
  • look for organ damage
    • blood samples
      • CBC + coagulation
      • renal and liver tests
      • NT-proBNP (heart failure)
      • cardiac enzymes (if ACS is suspected)
      • urine chemistry and urine sediment examination
      • D-dimers (when aortic dissection is suspected)
    • ECG
    • brain CT + CTA (in patients with acute neurological complaints/signs or head injury)
    • chest x-ray (in patients with dyspnea)
    • CTA of the chest and abdomen for suspected aortic dissection
    • fundoscopic exam (ophthalmoscopy)
  • exclude secondary hypertension
    • CT/MR angiography of renal arteries (renovascular hypertension)
    • plasma renin activity (PRA) and aldosterone, plasma or urine metanephrines

Blood pressure monitoring

  • arterial blood pressure (BP) monitoring is a cornerstone of hemodynamic monitoring in neurocritical care
  • both hypotension and hypertension can can be detrimental to vital organ function and worsen the patient’s outcome
  • BP monitoring techniques include:
    • noninvasive BP monitoring (more common)
      • intermittent (using inflatable cuff) – the proper cuff size is critical for accurate readings
        • manual (auscultatory, palpatory)
        • automated (oscillometric)
      • continuous
        • volume clamp method
        • arterial applanation tonometry
    • invasive BP measurement via arterial cannulation (most commonly automated)
  • choice of BP monitoring method must be individualized
    • low-risk patients – intermittent oscillometric BP monitoring
    • high-risk, hemodynamically unstable patients – continuous BP monitoring (either noninvasive or invasive)
    • critically ill patients/hypertensive emergencies – continuous invasive BP monitoring via an arterial catheter is preferred

Proper cuff size

  • the cuff bladder length should be at least 80% of the upper arm circumference
    • arm circumference < 35 cm – choose cuff size 16×30 cm (suitable for most patients)
    • arm circumference 35-44 cm – cuff size 16×36 cm
    • arm circumference > 45 cm – cuff size 16×42 cm

Preeclampsia and eclampsia

  • preeclampsia = new onset hypertension >140/90 mmHg + proteinuria > 500 mg/24 h or 300 mg/L occurring after 20 weeks gestation or during the second half of pregnancy
    • most commonly occurs during the 3rd trimester of pregnancy and may occur before, during, or after delivery
  • eclampsia = elevated BP associated with seizures, multi-organ damage (aspiration pneumonia, cerebral hemorrhage, renal failure, pulmonary edema, HELLP syndrome), and coagulopathy

Classification

The severity of a hypertensive crisis depends on:

  • current blood pressure
  • presence of acute target-organ damage
  • rate of BP increase (how long it took for BP to increase from baseline to current values)
Hypertensive emergency
  • life-threatening condition
  • hypertension + signs of organ damage
    • hypertensive encephalopathy (incl. hyperperfusion syndrome following revascularization procedures – CEA, CAS)
    • cardiac failure ± pulmonary edema
    • acute coronary syndrome (ACS)
    • aortic dissection
    • SAH/ICH
  • etiology
    • discontinuation of chronic antihypertensive medication
    • pre-/eclampsia
    • pheochromocytoma crisis
  • requires aggressive parenteral therapy
Hypertensive urgency
  • not a life-threatening condition; no evidence of organ damage (provoked by acute BP elevation)
  • usually results from the decompensation of chronic hypertension
    • decompensation during invasive procedures, panic attacks, or after administration of psychoactive substances (cocaine, meth)
  •  it can usually be managed on an outpatient basis
  • use oral medications and lower the blood pressure within 24 hours

Management of hypertensive emergency

  • admission + monitoring of vital signs (incl. continuous BP monitoring)
  • use analgesia or sedation is necessary
  • assess for target organ injury + initiate parenteral medications (rapid BP lowering is the mainstay of therapy)
  • except for aortic dissection, avoid excessive BP reduction (⇒ risk of cerebral and myocardial hypoperfusion, provocation of arrhythmias, etc.)
    • reduce mean BP by 20-25% in the first hour, then to 160/100 mm Hg over the next 2-6 hours, then gradually to baseline values over 2 days
    • aortic dissection: reduce SBP to < 100-120 mmHg + reduce heart rate to < 60/min within 20 minutes
  • use fast-acting and easily titratable antihypertensive drugs –  parenteral drugs allow bolus administration and continuous infusion
    • for patients with significant tachycardia, metoprolol or clonidine (which also has a sedative effect) are appropriate antihypertensive drugs
    • in pregnancy, IV hydralazine or oral nifedipine may be used; avoid ACE inhibitors or angiotensin receptor blockers (ARBs)
    • avoid nitrates in patients with intracranial hypertension
  • start specific treatment of affected organs
Hypertensive emergency
 Medication
 acute MI / unstable angina nitroglycerin or isosorbide dinitrate (ISOKET)
metoprolol (BETALOC) bolus 1,25–5 mg IV / esmolol (ESMOCARD, BREVIBLOC)
+ urapidil (EBRANTIL)
acute left-sided heart failure loop diuretics + vasodilators
nitroglycerine 1-10 mg/h / ISOKET + FUROSEMIDE (20-40mg)
enalapril (ENAP)
aortic dissection esmolol (ESMOCARD, BREVIBLOC) nebo metoprolol (BETALOC)
nitroprusid (NIPRUSS) (+ propanol)
reduce SBP  to < 100–120 mm Hg  + HR < 60/min within 20 minutes
hypertensive encephalopathy labetalol (TRANDATE) / urapidil (EBRANTIL) / esmolol (ESMOCARD, BREVIBLOC)
enalapril (ENAP)
 ICH
→ BP management in an acute stroke
   urapidil (EBRANTIL) / labetalol (TRANDATE)
SAH nimodipine (DILCEREN)  /  urapidil (EBRANTIL)
pheochromocytoma
abuse of the sympathomimetic drug
   urapidil (EBRANTIL) / isosorbide dinitrate (ISOKET) / labetalol (TRANDATE)
preeclampsia/eclampsia labetalol (TRANDATE) / nitropruside (NIPRUSS)
hydralazine i.v.  (2.5–20 mg in eclampsia with the insufficient effect of labetalol)
 renal insufficiency   urapidil (EBRANTIL) / furosemide (20-40mg)
rebound after discontinuing beta-blockers metoprolol (BETALOC)

FAQs

What is a hypertensive crisis?
  • a potentially life-threatening severe increase in blood pressure
  • systolic blood pressure (SBP) >180 mm Hg and diastolic blood pressure (DBP) > 120 mm Hg
  • the term hypertensive crisis is now replaced by the terms hypertensive emergency and hypertensive urgency

What is the difference between hypertensive emergency and hypertensive crisis?
  • hypertensive emergency – severe hypertension (>180/120 mm Hg) associated with new or progressive end-organ damage
  • hypertensive urgency –  severe hypertension (>180/120 mm Hg) with no signs of new organ damage

What causes a hypertensive crisis?
  • common causes include non-adherence to antihypertensive medication, stroke, heart attack, kidney failure, or aortic dissection
What are the symptoms of a hypertensive crisis?
  • symptoms may include severe headache, shortness of breath, chest pain, back pain, numbness/weakness, change in vision, or difficulty speaking

What are the potential complications of a hypertensive crisis?
  • possible complications include stroke, heart attack, kidney failure, loss of vision, or damage to other vital organs

What is the first thing to do in hypertensive crisis?
  • intravenous administration of antihypertensive drugs to lower the person’s blood pressure
  • BP should be reduced by no more than 25% in the first hour, as rapid decreases in blood pressure can cause other problems (except for aortic dissection)
  • underlying causes must be addressed

What is the survival rate for hypertensive crisis?
  • mortality rates for patients experiencing hypertensive crisis are usually reported ~ 7-9%

You cannot copy content of this page

Send this to a friend
Hi,
you may find this topic useful:

Hypertensive crisis
link: https://www.stroke-manual.com/hypertensive-crisis/