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What is BP?
Force exerted by blood against artery wall during ventricular contraction (systolic) and ventricular relaxation (diastolic) must be adequate to maintain tissue perfusion during activity and rest.
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What are the two main factors that influence BP?
- Cardiac Output
- Systemic Vascular Resistance
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What regulates BP?
- Sympathetic Nervous System (SNS)
- Cardiovascular System
- Renal and Endocrine System
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What is hypertension?
- Sustained elevation of BP
- Systolic is > or = 140 mmHg and diastolic is > or = to 90 mmHg for extended periods of time
- Diagnosis based on 3 occasions of elevation within a several week period.
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What effects does hypertension have on the body?
- High BP means the heart is working harder than normal, both heart and blood vessels are under strain
- Endothelial damage occurs
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What are hypertensive patients at risk for?
- MI
- CHF
- CVA
- Renal Failure
- PVD
- Retinal damage
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What are the symptoms of HTN?
- Often asymptomatic
- "SILENT KILLER!"
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Who is at risk for HTN?
- Increased age
- African-Americans
- More prevalent in men than women
- Women after the age of 55
- Equal risk for men and women from 55-75 years of age and after 75 years of age more prevalent in women.
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What is Primary HTN?
- Elevated BP without an underlying disease
- Accounts for 90-95% of all cases of Htn
- Caused by high sodium diets, obesity, sedentary lifestyles, etc
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What is Secondary HTN?
-Elevated BP with specific underlying cause—identify and correct underlying problem which usually corrects HTN as well
-Its the main cause of Htn in children (80%)
- Causes:
- -Hypokalemia
- -narrowing of the aorta
- -tachycardia
- -renal disease
- -Meds (NSAID’s)
- -Neurologic disorders (brain tumors)
- -endocrine disorders (Hyperaldosteronism)
- -Obstructive Sleep Apnea
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Clinical Manifestations of HTN
May be asymptomatic, also known as “silent killer”, until it causes damage to target organs
- Secondary symptoms:
- -fatigue
- -decrease in activity
- -dizziness
- -palpitations
- -angina
- -dyspnea
- -H/A
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Complications (Target Organ Diseases): CAD
- Htn is major risk factor
- exact mechanism unknown
- thought to be caused by a disruption of coronary artery endothelium due to high pressures
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Complications (Target Organ Diseases): Left Ventricular Hypertrophy
- Sustained high pressures increase cardiac workload
- Adaptive mechanism to increase CO by increasing contraction
- Heart failure occurs when the heart can no longer compensate for the increased pressures and demand to supply oxygen (enlarged heart on X-ray, SOB on exertion, fatigue, ECG changes-wide QRS, inverted T wave).
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Complications (Target Organ Diseases): CVD
- Atherosclerosis is the most common cause of CVD
- Risk for stroke is 4 times higher in people with Htn
- If atherosclerotic plaques in carotid arteries can break off and cause TIA’s or a stroke
- Hypertensive encephalopathy may occur after prolonged Htn
- When blood pressure remains high, the cerebral blood vessels dilate producing edema and marked loss of consciousness and death may occur from brain damage
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Complications (Target Organ Diseases): PVD
- Htn speeds up the process of atherosclerosis in the peripheral blood vessels
- Classic symptom: Intermittent claudication (ischemic muscle pain caused by activity, relieved with rest).
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Complications (Target Organ Diseases): Nephrosclerosis
- Htn is the leading cause of end-stage renal disease!
- Direct result of ischemia caused by the narrowed lumen of intrarenal blood vessels
- Leads to atrophy of the tubules, destruction of the glomeruli, and eventual death of the nephron itself
- Lab tests to confirm are: BUN, creatinine, proteinuria, albuminuria, hematuria
- Nocturia is the earliest sign of renal dysfunction
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Complications (Target Organ Diseases): Retinal damage
- The retina is the only place in the body where blood vessels can be directly visualized
- Includes blurring of vision, retinal hemorrhages, loss of vision
- Damage to the retina gives an indication of cardiac vessel damage
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What are the classifications of HTN?
- Normal: SBP < 120 DBP < 80 (encourage healthy lifestyle)
- Prehypertension: SBP 120-139 DBP 80-89 (strongly pursue lifestyle changes)
- Stage 1 HTN: SBP 140-159 or DBP 90-99 (initiate drug therapy, Thiazide = 1st line of treatment)
- Stage 2 HTN: SBP >160 or DBP > 100 (initiate two drug combination)
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What are the 1st line Agents for HTN?
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What are Beta Blockers used in?
-BBs can mask the signs of hypoglycemia and cause bronchospasm so monitor airway/breathing!
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What lifestyle modifications should be made?
- -Dietary Changes
- -DASH diet
- -Limit alcohol consumption
- -Regular physical activity
- -Avoid tobacco use
- -Stress management
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What type of diet should patients with HTN follow?
-Low Sodium (2g or less/day)
-Educate patient on how to read labels and about foods high in sodium (processed & canned foods, etc)
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What effect does Diuretics have on Preload, Afterload, and Contractility?
-Decreases preload
-Monitor fluids & Lytes
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What effect does Beta Blockers have on Preload, Afterload, and Contractility?
- -Decreases contractility & rate
- -Slightly decreases afterload
-Monitor for bradycardia, bronchospasm, and masked symptoms of hypoglycemia
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What effect does Calcium Channel Blockers have on Preload, Afterload, and Contractility?
- -Decreases contractility
- -Decreases afterload
-Monitor for headache, edema, CHF
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What effect does ACE Inhibitors have on Preload, Afterload, and Contractility?
- -Decreases afterload
- -Decreases preload
-Monitor renal fxn & potassium(same with ARBs) and for cough & angioedema
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What are reasons for non-adherance with HTN meds?
- Cost
- Side Effects (sexual dysfuntion, fatigue, frequent urination)
- Knowledge Deficit
- Lack of Symptoms
- Ask the Questions!!!
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What is Hypertensive Crisis?
- -Severe abrupt elevation in BP
- -Diastolic > 140 mm Hg
- What is the etiology:
- -Abruptly stopping Beta Blockers or Clonidine
- -Non-compliance (of meds and new lifestyle modifications)
- -Street Drugs
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What is Hypertensive Emergency?
Evidence of evolving organ damage to other organs besides the heart (target organ damage)
- Examples:
- -MI
- -Angina
- -TIA/CVA
- -Encephalopathy
- -Renal Failure
- -Aortic Dissection
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What is Hypertensive Encephalopathy?
Changes in capillary permeability causing cerebral edema
- Symptoms:
- -HA
- -N/V
- -seizures
- -confusion
- -coma
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What is the Nursing Care for Hypertensive Emergency?
- Admit to ICU
- Continuous Monitoring (A-line, Tele, CVP monitor, etc)
- IV Nitroprusside via pump (potent vasodilator; decreases preload & afterload)
- titrate to BP
- Alternative= Cleviprex ( IV CCB)
- Gradually reduce MAP
- 25% in one hour (too rapid can cause CVA)
- 160/100-110 within 2-6 hours
- Monitor for signs of target organ damage (frequent neuro exams, EKG, cardiac enzymes, urine output, etc)
- Patient education when crisis resolved
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What is Hypertensive Urgency?
Very high BP with no symptoms; BP is high enough to cause serious problems but isn't currently
- Treated inpatient, ED or outpatient:
- -monitor response to treatment
- -pt can go home if BP stabilizes
- -requires follow-up within 24 hours
Can be given oral drugs (Clonidine or Captopril)
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Hypertensive Nursing Care
- D - Daily weights
- I - I&O
- U - Urine output
- R - Response of BP
- E - Electrolytes
- T - Take pulses
- I - Ischemic episodes (TIA)
- C - Complications (4 C's: CAD, CRF, CVA, CHF)
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