Page 57 - Critical Care Notes

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■ Cause for concern: ST depression or elevation of 1–2 mm that lasts for
at least 1 min can be clinically significant and warrants further patient
assessments.
■ Refer to AACN Practice Alert at http://www.aacn.org/WD/Practice/Docs/
PracticeAlerts/ST_Segment_Monitoring_05-2009.pdf.

Hypertensive Crisis
Hypertensive crisis is defined as a severe elevation in blood pressure (systolic
BP >179 mm Hg, diastolic BP >109 mm Hg), which may or may not lead to organ
damage. There are two types of hypertensive crisis:
■ Hypertensive emergency: Rapid (hours to days) marked elevation in BP
(SBP >180 mm Hg or DBP >120 mm Hg) → acute organ tissue damage.
■ Hypertensive urgency: Slow (days to weeks) elevation in BP (SBP >180 mm Hg
or DBP >110 mm Hg) usually does not lead to organ tissue damage.
Pathophysiology
Any disorder or cause (essential hypertension, renal parenchymal disease, re -
novascular disease, pregnancy, endocrine drugs, autonomic hyperreactivity,
CNS disorder) → ↓ BP → vessel becomes inflamed → leak fluid or blood to the
brain → CVA → long-term disability. Intense vasoconstriction may also cause
encephalopathy, myocardial ischemia or infarction, acute pulmonary edema,
aortic dissection, and acute renal failure, among other conditions.
Clinical Presentation
Hypertensive crisis manifests with:
■ Chest pain
■ Dyspnea, orthopnea, paroxysmal nocturnal dyspnea
■ Neurological deficits
■ Severe, throbbing headache
■ Visual disturbances
■ Nausea and vomiting
■ Dysphagia
■ Back pain
■ Severe anxiety
■ Irritability, confusion
■ Possible seizures
■ Oliguria if kidneys affected

CV