Understanding Hypertension

Key Terms

• Cardiac output is the amount of blood the heart pumps.
• Diastolic refers to the pressure in the arteries when the heart rests between beats.
• Hypertension refers to high blood pressure.
• Hypertensive emergency is a severe form of high blood pressure that can lead to stroke, heart attack, and kidney damage.
• Hypertensive urgency is a condition in which blood pressure is very high but there is no evidence of target organ damage.
• Hypertrophy is enlargement of an organ or tissue from the increase in size of its cells.
• Peripheral vascular resistance refers to the resistance of blood flow in the peripheral vessels
• Plaque is a deposit of fatty material on the inner lining of an arterial wall
• Primary hypertension is high blood pressure with no known cause.
• Secondary hypertension is high blood pressure caused by another medical condition.
• Systolic refers to the pressure in the arteries when the heart beats.
• Viscosity refers to the thickness of a fluid.

Chapter Concepts

• Caring for patients with hypertension involves a comprehensive approach that addresses their physical, emotional, and social needs
• Health promotion, including education and lifestyle modifications, is essential for preventing and managing hypertension.
• Perfusion is the process of delivering blood to the body's tissues and organs which can be affected by high blood pressure.
• Teaching and learning about hypertension helps the patient in understanding their condition, treatment plan and lifestyle modifications

Learning Outcomes

• Classifications of hypertension in adults, pathophysiology, causes and risk factors, signs and symptoms are the learning outcomes for patients with hypertension
• The other learning outcomes are therapeutic measures, defining hypertensive emergency, complications of hypertension and evaluation of nursing interventions

Hypertension Basics

• Consistent elevation in blood pressure results in hypertension, a primary risk factor for cardiovascular disease (CVD) and stroke
• Hypertension was the 13th leading cause of death in 2017, with a 4.7% increase from 2016
• The American College of Cardiology (ACC) and the American Heart Association (AHA) redefined normal and abnormal BP for adults ages 18 and older

Pathophysiology

• Blood pressure (BP) is a measure of the pressure exerted by blood on the walls of the blood vessels
• BP is determined by cardiac output (CO), peripheral vascular resistance (PVR), the viscosity of the blood, and the amount of circulating blood volume
• Decreased stretching ability of blood vessels, increased blood viscosity, and/or increased fluid volume may cause an increase in BP
• Factors that impair normal regulation of BP may lead to hypertension
• Sympathetic nervous system overstimulation causes vasoconstriction, and alterations in baroreceptors and chemoreceptors may influence the development of hypertension
• Increases in hormones that cause sodium retention, such as aldosterone, lead to increased fluid retention
• Changes in kidney function, altering the excretion of fluid, also results in excess fluid volume that may contribute to hypertension.

Hypertension Classifications (Table 22.1)

• Normal BP is defined as less than 120 mm Hg systolic and less than 80 mm Hg diastolic
• Elevated BP is 120-129 mm Hg systolic and less than 80 mm Hg diastolic
• Stage 1 hypertension is 130–139 mm Hg systolic or 80-89 mm Hg diastolic
• Stage 2 hypertension is equal to or greater than 140 mm Hg systolic or equal to or greater than 90 mm Hg diastolic
• Individuals with SBP and DBP in 2 categories should be designated to the higher BP category
• BP indicates blood pressure based on an average of ≥2 careful readings obtained on ≥2 occasions

Types of Hypertension

• Primary hypertension (formally essential hypertension) is elevation of systolic and/or diastolic BP with no identifiable cause
• Secondary hypertension has a known cause and occurs as the result of another disease process, such as a kidney abnormality or a tumor of the adrenal gland
• When the cause of secondary hypertension is treated before permanent structural changes occur, BP usually returns to normal

Signs and Symptoms

• Patients with hypertension are often first diagnosed when seeking health care for reasons unrelated to hypertension because it often does not exhibit symptoms for many years
• A patient with hypertension may report a headache, bloody nose, severe anxiety, or shortness of breath in a small number of cases

Risk Factors

• Social determinants of health (SDOH) categorized by Healthy People 2030 as economic stability, education access and quality, health-care access and quality, neighborhood and built environment, and social and community context can influence the development and management of hypertension
• Nonmodifiable risk factors include a family history of hypertension, age, and ethnicity
• Modifiable risk factors include blood glucose level, activity level, smoking, salt and alcohol intake, and insufficient sleep
• Genetics, environmental risk factors, and lifestyle habits affect how people age, resulting in wide variations of BP among older adults
• High BP is more common in non-Hispanic Black adults (54%) than in non-Hispanic White adults (46%), non-Hispanic Asian adults (39%), or Hispanic adults (36%)
• Hypertension among Black individuals is often caused by increased renin activity, resulting in greater sodium and fluid retention
• Lifestyle modifications to reduce hypertension risk include access to health care, maintenance of a healthy weight, reduced sodium intake, adequate potassium intake, reduced alcohol consumption, regular physical activity, and compliance with medication regimen

Reducing Blood Pressure With Diet

• The Dietary Guidelines for Americans 2020–2025 recommend a sodium intake of 2,300 mg for healthy adults
• Those with hypertension should reduce their sodium intake more; the average sodium intake of Americans is 3,393 mg per day
• Examples of low-sodium dietary patterns include the Dietary Approaches to Stop Hypertension (DASH) dietary pattern, Healthy Mediterranean-Style Dietary Pattern, and Healthy Vegetarian Dietary Pattern (USDA, 2020)
• A person following the DASH Eating Plan on a 2,000-calorie diet would consume 6-8 servings of grains, 4-5 servings of vegetables and fruits, 2-3 servings of low-fat or fat-free dairy, 6 or less servings of meat(lean), poultry, or fish, and fats and oils, preferably monounsaturated
• Many adults who have diabetes mellitus also have hypertension; lifestyle modifications and adherence to therapy are crucial to prevent heart attacks, strokes, blindness, and kidney disease associated with high blood glucose and BP levels
• The DASH diet led to significant reductions in both systolic and diastolic BP

Nursing Interventions and Patient Safety

• Priority nursing diagnoses include readiness for enhanced health literacy, ineffective health self-management and risk for unstable blood pressure
• BP should be measured at least every year after the age of 3; diagnosis of hypertension requires that at least two BP measurements are taken at different points in time, usually a week(s) apart, preferably by an ambulatory or home monitoring BP monitoring device
• A patient's risk factors, presence of signs and symptoms, history of kidney or heart disease, and current use of medications are also considered
• A combination of genetic (nonmodifiable) and environmental (modifiable) risk factors are thought to be responsible for the development of hypertension
• Assess the patient's health history, BP measurements, medications, and physical assessment
• Determine what hypertensive patients and their families know about hypertension and associated risk factors

Therapeutic Measures

• The 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults defines pharmacologic treatment thresholds and recommends drug therapy
• Treatment begins with lifestyle modifications and then individualized consideration of antihypertensive medication therapy
• A treatment plan of lifestyle modifications and medications is effective if patients are motivated to accept the diagnosis of hypertension
• Maintain empathy and trust between patients and nurses to increase patient motivation
• Antihypertensive medications can have unpleasant side effects
• Explain to patients who take antihypertensive drugs to change positions slowly to prevent the effects of orthostatic hypotension and the risk of falling

Gerontological Issues

• Deficiencies in fluid volume are a common problem for older adults; diuretics can worsen dehydration and careful monitoring of fluid balance is important to prevent dehydration
• Older adults may be more sensitive to medications and require lower dosages; monitor them carefully for adverse effects

Complications

• Common complications of hypertension include coronary artery disease, atherosclerosis, myocardial infarction (MI), heart failure (HF), stroke, and kidney or eye damage
• High BP levels may also increase the size of the left ventricle, referred to as hypertrophy
• Over time, elevated BP damages the small vessels of the heart, brain, kidneys, and retina

Hypertension Medications

• Diuretics increase urine output by inhibiting sodium and water reabsorption by the kidney (thiazide and thiazide-like, loop and potassium-sparing diuretics)
• Sympatholytics (Beta Blockers) decrease sympathetic nervous system response, resulting in decreased BP, heart rate, contractility, cardiac output, and renin activity
• Alpha-1 Blockers block effects of sympathetic nervous system on smooth muscle of blood vessels, resulting in vasodilation and decreased BP
• Central-Acting Alpha-2 Agonists block effects of sympathetic nervous system centrally and Combined Alpha and Beta Blockers block alpha-adrenergic receptors, causing vasodilation and reduced BP
• Angiotensin-Converting Enzyme (ACE) Inhibitors block production of angiotensin II, a potent vasoconstrictor; reduces peripheral arterial resistance and BP
• Angiotensin II Receptor Blocker (ARB) blocks angiotensin II receptors, causing vasodilation and reduction in BP
• Aldosterone Receptor Antagonist blocks binding of aldosterone at the receptor site to reduce sodium reabsorption and then BP
• Calcium Channel Blocker (CCB) prevents movement of extracellular calcium into the cell causing vasodilation
• Direct Vasodilators relax smooth muscles of blood vessels, causing vasodilation and decreased BP
• Combination Agents often given with a diuretic to reduce edema resulting from water and sodium retention

Patient Teaching

• Walking for 30 minutes is an effective way to lower BP, as is listening daily to 30 minutes of classical, Celtic, or raga type music while practicing slow abdominal breathing; transcendental meditation also helps control high BP
• Lifestyle modifications mnemonic: Limit salt, caffeine, and alcohol; Include daily potassium and calcium; Fight fat and cholesterol; Exercise regularly (e.g., walking); Stay on your BP regimen; Try to quit smoking; Your medications are to be taken daily; Lose weight; End-stage complications will be avoided!

Hypertensive Emergency

• Hypertensive emergency occurs with elevations in systolic BP higher than 180 mm Hg or diastolic BP higher than 120 mm Hg
• Risk for or progression of target-organ dysfunction (such as MI, HF, dissecting aortic aneurysm) requires immediate BP treatment in an intensive care unit
• Gradual reduction of BP is often desired to prevent decreased blood flow to the kidneys, heart, and/or brain
• An IV medication such as nitroprusside (Nipride) may be given to reduce BP during the crisis
• The nursing diagnosis Risk for Unstable Blood Pressure is applicable to the patient with hypertensive emergency

Hypertensive Urgency

• Acute hypertensive urgency occurs when the BP is as elevated as in a hypertensive emergency but without progression of target-organ dysfunction
• A patient with hypertensive urgency may have severe headaches, nosebleeds, shortness of breath, and severe anxiety
• Appropriate oral medication is implemented with a follow-up visit within several days

General notes

• BP should be controlled before the patient has an invasive procedure because hypertensive patients are at greater risk for strokes, MI, HF, kidney disease, and pulmonary edema
• Hypertension often causes no signs or symptoms other than elevated BP readings, resulting in being referred to as the "silent killer.”
• Nursing interventions are effective if the patient can explain hypertension, including its risk factors, complications, and treatment regimen; how lifestyle changes will be made; how problem-solving for barriers to therapy will be made.