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Define hypertension and how it is diagnosed.
sustained elevation of BP (>140/90)
- Diagnosis based on elevated readings at
- least 3 times over a period of a week or longer
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What is hypertensive crisis and name some of the causes for which the nurse would assess.
- severe & abrupt BP elevation
- BP >180/120
- rises quickly
- can be due to noncompliance, crack cocaine use, tumor of the adrenal medulla, etc.
- Interventions:-place pt in semi-fowler's position
- -administer oxygen
- -Administer IV nitroprusside (Nitropress), nicardipine (Cardene IV), or other infusion drug as prescribed (for nitroprusside, cover infusion bag to prevent drug breakdown by light).
- -Monitor blood pressure every 5 to 15 minutes until the diastolic pressure is below 90 and not less than 75; then monitor blood pressure every 30 minutes.
- -Observe for neurologic or cardiovascular complications, such as seizures; numbness, weakness, or tingling of extremities; dysrhythmias; or chest pain.
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State the difference between primary (essential) and secondary (non-essential) hypertension.
- Primary (essential):
- -95% of all cases
- -Usually >60 years
- -Unknown cause
- -risk factors:
- •Family history of hypertension
- •High sodium intake
- •Excessive calorie consumption
- •Physical inactivity
- •Excessive alcohol intake
- •Low potassium intake
- Secondary (non-essential):
- -5% of all cases.
- -Elevated BP with a specific cause that can be identified and corrected
- -Suspected in persons <20 or >50 with sudden onset
- -renal disease is the most common cause
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List four major organ complications that can occur as a result of hypertension.
- ***STROKE (CVA)***MI
- peripheral vascular disease (PVD)
- renal failure
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Why assess BP in both arms?
- use the higher BP reading
- atherosclerosis
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How often should BP be monitored once stabilized?
Monitor blood pressure every 5 to 15 minutes until the diastolic pressure is below 90 and not less than 75; then monitor blood pressure every 30 minutes.
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Metabolic Panel
- a frequently ordered panel of tests that gives your doctor important information about the current status of your kidneys, liver, and electrolyte and acid/base balance as well as of your blood sugar and blood proteins.
- determines any liver or kidney damage
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Serum Creatinine
- Measuring serum creatinine is a useful and inexpensive method of evaluating renal dysfunction.
- elevated = renal impairment
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Diuretics
decrease blood volume and lower BP
The most frequent side effect associated with diuretics is hypokalemia (low potassium levels). Monitor the serum potassium level and assess for irregular pulse and muscle weakness, which may indicate hypokalemia. Teach patients taking potassium-depleting diuretics to eat foods high in potassium, such as bananas and orange juice.
Diuretics are the drugs of choice for patients who have asthma, chronic airway limitation, chronic renal disease, and select cases of heart failure.
thiazide - prevent sodium and water reabsorption in the distal tubes of the kidneys while promoting K+ excretion
- loop - depress Na reabsorption in the ascending loop of the Henle and PROMOTE Na & K+ excretion (ex: lasix)
K+ sparing - act on the distal tubule to inhibit reabsorption of sodium ions in exchange for potassium, thereby retaining potassium. (ex: spironolactone (Aldactone, Novospiroton)
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ACE Inhibitors
blocks the action of ACE as it attempts to convert angiotensin I to angiotensin II (one of the most powerful vasoconstrictors in the body. this results in vessels constricting less, which lowers BP.
more effective than ARBs
ex - capoten and vasotec
Instruct the patient receiving an ACE inhibitor for the first time to get out of bed slowly to avoid the severe hypotensive effect that can occur with initial use. Orthostatic hypotension may occur with subsequent doses, but it is less severe. If dizziness continues or there is a significant decrease in the systolic blood pressure (more than a change of 20 mm Hg), notify the health care provider or teach patients to notify their provider. The older patient is at the greatest risk for postural hypotension because of the cardiovascular changes associated with aging. If a cough develops, the drug is discontinued.
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ARBs
selectively block the binding of angiotensin II to its receptor in the vascular and adrenal tissues by competing directly with angiotensin II but not inhibiting ACE.
ex: candesartan (Atacand) and losartan (Cozaar)
does not cause a cough
does not work as well in african-americans
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Calcium Channel Blockers
interferes with the transmembrane flux of Ca+ ions, which results in vasodilation (which decreases BP).
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Beta Blockers
- Cardioselective (affects only cardiac system):
- lowers BP by blocking beta-receptors in the heart and peripheral vessels, reducing cardiac rate & output. By blocking these receptors, these drugs decrease HR and myocardial contractility.
Non-cardioselective beta blockers are usually not prescribed for patients with respiratory disorders because they prevent normal dilation of the bronchi. This can cause pulmonary vasoconstriction and respiratory compromise.
***masks signs of HYPOGLYCEMIA*** be careful with diabetics
Beta blockers are the drug of choice for hypertensive patients with ischemic heart disease (IHD) because the heart is the most common target of end-organ damage with hypertension.
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Adrenergic Inhibitors
dilate arterioles and veins
These drugs can lower blood pressure quickly, but their use is limited because of frequent and bothersome side effects.
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