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.
What are the two main factors that influence BP?
- Cardiac Output
- Systemic Vascular Resistance
What regulates BP?
- Sympathetic Nervous System (SNS)
- Cardiovascular System
- Renal and Endocrine System
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.
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
What are hypertensive patients at risk for?
- Renal Failure
- Retinal damage
What are the symptoms of HTN?
- Often asymptomatic
- "SILENT KILLER!"
Who is at risk for HTN?
- Increased age
- 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.
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
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%)
- -narrowing of the aorta
- -renal disease
- -Meds (NSAID’s)
- -Neurologic disorders (brain tumors)
- -endocrine disorders (Hyperaldosteronism)
- -Obstructive Sleep Apnea
Clinical Manifestations of HTN
May be asymptomatic, also known as “silent killer”, until it causes damage to target organs
- Secondary symptoms:
- -decrease in activity
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
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).
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
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).
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
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
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)
What are the 1st line Agents for HTN?
What are Beta Blockers used in?
-BBs can mask the signs of hypoglycemia and cause bronchospasm so monitor airway/breathing!
What lifestyle modifications should be made?
- -Dietary Changes
- -DASH diet
- -Limit alcohol consumption
- -Regular physical activity
- -Avoid tobacco use
- -Stress management
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)
What effect does Diuretics have on Preload, Afterload, and Contractility?
-Monitor fluids & Lytes
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
What effect does Calcium Channel Blockers have on Preload, Afterload, and Contractility?
- -Decreases contractility
- -Decreases afterload
-Monitor for headache, edema, CHF
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
What are reasons for non-adherance with HTN meds?
- Side Effects (sexual dysfuntion, fatigue, frequent urination)
- Knowledge Deficit
- Lack of Symptoms
- Ask the Questions!!!
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
What is Hypertensive Emergency?
Evidence of evolving organ damage to other organs besides the heart (target organ damage)
- -Renal Failure
- -Aortic Dissection
What is Hypertensive Encephalopathy?
Changes in capillary permeability causing cerebral edema
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
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)
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)