Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Chapter 38 Hypertension Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Definitions The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure Normal blood pressure Systolic: <120 mm Hg; diastolic <80 mm Hg Prehypertension Systolic pressures between 120 and 139; diastolic pressures between 80 and 89 Stage 1 and stage 2 hypertension See Table 38-1 What risks are included in each of the Risk Groups A, B, and C? Some people have only occasional elevations in blood pressure and normal readings at other times; this is called isolated pressure elevations. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Types of Hypertension Primary hypertension 90% to 95% of all cases of hypertension Its cause is unknown Secondary hypertension Caused by underlying factors, such as kidney disease, certain arterial conditions, some drugs, and occasionally pregnancy Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Anatomy and Physiology of Blood Pressure Regulation Cardiac output The volume of blood pumped by the heart in a specific period (usually 1 minute) Determined by strength, rate, and rhythm of the contraction of the left ventricle and the blood volume Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Anatomy and Physiology of Blood Pressure Regulation (cont.) Peripheral vascular resistance Force in the blood vessels that left ventricle must overcome to eject blood from the heart Resistance to blood flow determined by diameter of the blood vessels and blood viscosity (thickness) Increased peripheral vascular resistance: the most prominent characteristic of hypertension Why does increased peripheral vascular resistance occur? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Anatomy and Physiology of Blood Pressure Regulation (cont.) Diameter of blood vessels regulated by the vasomotor center Sympathetic nervous system tracts from the medulla extend down the spinal cord to the thoracic and abdominal regions Stimulation of sympathetic nervous system causes release of the hormones norepinephrine and epinephrine Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Anatomy and Physiology of Blood Pressure Regulation (cont.) Norepinephrine and epinephrine (catecholamines) are vasoconstrictors: cause blood vessels to constrict, making diameter smaller By constricting blood vessels, norepinephrine increases peripheral vascular resistance and raises blood pressure Epinephrine constricts blood vessels and increases the force of cardiac contraction, causing blood pressure to rise Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Anatomy and Physiology of Blood Pressure Regulation (cont.) Vasoconstriction decreases blood flow to the kidneys, which then release renin Renin leads to the formation of angiotensin, another potent vasoconstrictor Angiotensin stimulates the adrenal cortex to secrete aldosterone, a hormone that promotes sodium and water retention This results in an increased blood volume Vasoconstriction, cardiac stimulation, and retention of fluid all contribute to hypertension Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Age-Related Changes Affecting Blood Pressure Atherosclerotic changes reduce the elasticity of the arteries, causing decrease in cardiac output and increase in peripheral vascular resistance Pulse pressure (the difference between the systolic and diastolic pressures) widens in response to a decreased ability of the aorta to distend After age 60 years, peripheral vascular resistance increases by approximately 1% per year. Why does the systolic pressure rise in the older adult? Because research has shown that older people benefit from controlling hypertension, age is no longer considered a barrier to aggressive treatment. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Risk Factors Dyslipidemia Atherosclerosis Diabetes mellitus Tobacco use Age >55 years for men or age >65 years for women Family history Father or brother with heart disease before age 55; mother or sister with heart disease before age 65 Sedentary lifestyle Obesity Other risk factors include stress, overstimulation, and a family history of obesity, hypertension, or dyslipidemia. What stimulants may contribute to or aggravate hypertension? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Signs and Symptoms Occipital headaches that are more severe on arising Lightheadedness Epistaxis If hypertension has damaged blood vessels in the heart, kidneys, eyes, or brain, patient may have symptoms of impaired function of those organs Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Complications Heart Coronary artery disease develops in patients with hypertension two to three times more frequently than in people with normal blood pressures Kidneys Narrowing of the renal arteries may decrease renal function and lead to chronic renal failure Coronary artery disease reduces blood supply to the myocardium, which can result in angina, myocardial infarction, and congestive heart failure. What may cause left ventricle hypertrophy? Initial indicators of renal failure are nocturia (need to urinate during the night) and azotemia (accumulation of nitrogen waste products in the blood). Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Complications (cont.) Brain Prolonged hypertension constricts and damages cerebral arteries, putting patient at risk for transient ischemic attacks and cerebrovascular accidents Eyes Damage to eyes may include narrowing of the retinal arterioles, retinal hemorrhages, and papilledema; may lead to blindness What is a transient ischemic attack? People with hypertension have a sevenfold greater incidence of cerebrovascular accidents than those with normal blood pressures. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Diagnostic Tests and Procedures Confirmed by repeated findings of average pressures equal to or greater than 140/90 Ambulatory blood pressure monitors Provider collects data about patient’s lifestyle, other cardiovascular risk factors, and other medical diagnoses Electrocardiogram Blood studies include glucose, hematocrit, potassium, calcium, creatinine, and a lipid profile Chest radiograph Why would providers feel there is no need to find the cause of a patient’s hypertension? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Medical Treatment Lifestyle modifications Weight reduction Smoking cessation Sodium and alcohol restriction Exercise Relaxation techniques Reduction of weight can reduce blood pressure by reducing the cardiac workload. Stopping smoking eliminates vasoconstriction caused by nicotine. Reduction of sodium in the body reduces water retention and decreases the blood volume. A planned program of exercise improves cardiac efficiency by increasing cardiac output and decreasing peripheral vascular resistance. Relaxation therapy, biofeedback, and behavior modification techniques also may be used to reduce stress and lower blood pressure. How much should alcohol intake be limited? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Medical Treatment (cont.) Pharmacologic therapy Specific antihypertensive drugs Diuretics Beta-adrenergic receptor blockers Calcium antagonists Angiotensin-converting enzyme (ACE) inhibitors (ACEIs) Angiotensin II receptor antagonists (ARBs) Central adrenergic blockers Alpha-adrenergic receptor blockers Direct vasodilators What is the goal of drug therapy? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Medical Treatment (cont.) Pharmacologic therapy Nursing implications Administering the drugs to inpatients Monitoring for therapeutic and adverse effects Teaching patients about their drugs Older patients are at greater risk for adverse effects of medications because of reduced liver and kidney function. Why do antihypertensive drugs cause older adults to be at risk for falls? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Question 1 Secondary hypertension is most often caused by _______ disease. cardiovascular respiratory renal metabolic Correct answer: C Rationale: Secondary hypertension is more common in preadolescent children, with most cases caused by renal disease. The presence of childhood hypertension may contribute to the early development of CAD. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Question 2 The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) defines normal blood pressure as ________. systolic pressure of less than 110 mm Hg and diastolic pressure of less than 60 mm Hg systolic pressure of less than 120 mm Hg and diastolic pressure of less than 80 mm Hg systolic pressure of less than 130 mm Hg and diastolic pressure of less than 70 mm Hg systolic pressure of less than 140 mm Hg and diastolic pressure of less than 90 mm Hg Correct answer: B Rationale: The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) defines normal blood pressure as systolic pressure of less than 120 mm Hg and diastolic pressure of less than 80 mm Hg. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Secondary Hypertension Has a specific known cause and is less common than primary hypertension Causes Renal disease Excess secretion of adrenal hormones Narrowing of the aorta Increased intracranial pressure Some drugs such as vasoconstrictors Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Interventions: Ineffective Self-Health Management Diet therapy goals Maintain ideal body weight; prevent fluid retention Exercise Walking is highly recommended: increases cardiovascular functioning, burns calories, relieves stress, and promotes a sense of well-being A diet low in saturated fats with no more than 2 g of sodium is often prescribed. What is the maximum daily intake of sodium recommended by the National Research Council? If the patient is taking a potassium-wasting diuretic, dietary potassium intake may need to be increased or potassium supplements may be recommended. The DASH (Dietary Approaches to Stop Hypertension) eating plan can not only help lower blood pressure in people with hypertension, but also decrease the risk of a person developing hypertension. Advise patients to ask their providers before beginning new exercise programs. Instruct them to increase their activities gradually over a period of time. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Interventions: Ineffective Self-Health Management (cont.) Stress management Help patients identify stressors in their lives and explore ways to reduce them Drug therapy Review the name, dosage, purpose, and side effects of any prescribed medications Patients need to be well-informed about their medications. What adverse effects may be caused by suddenly stopping antihypertensive drugs? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Interventions Risk for injury Orthostatic hypotension Sudden drop in systolic blood pressure, usually 20 mm Hg, when going from lying or sitting to a standing position Monitor for lightheadedness, dizziness, syncope Sedation Advise if drowsiness is likely so activities requiring alertness can be avoided during times of peak drug effect Taking medications at bedtime to promote sleep How should patients who are prone to orthostatic hypotension be advised to prevent falling? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Interventions (cont.) Ineffective coping If depression is a side effect of an antihypertensive, consult provider to substitute another drug Sexual dysfunction Decreased libido, inability to achieve an erection, or delayed ejaculation Advise provider so an alternative medication or other intervention can be considered What is the best way to introduce the subject of sexual dysfunction to a patient? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Older Patients Response to drug therapy more difficult to predict; side effects are more common Orthostatic hypotension and sedation problematic for the older person, who is prone to fall and suffer serious injuries Depression also must be taken very seriously because it lowers motivation, impairs quality of life, and can lead to suicide What effects can depression have on the older patient? The older patient should be treated just like a younger patient in the assessment and management of distressing drug effects. Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Hypertensive Emergencies A life-threatening medical emergency Severe headache, blurred vision, nausea, restlessness, and confusion Elevated diastolic blood pressure (130 mm Hg or more); the heart and respiratory rates are increased May result from having stopped taking antihypertensive drugs Malignant hypertension is a specific type of hypertensive emergency in which the diastolic pressure exceeds 140 mm Hg. In what population is hypertensive crisis most commonly seen? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Hypertensive Emergencies (cont.) Causes: malignant hypertension, hypertensive encephalopathy, eclampsia, pheochromocytoma (adrenal tumor), cerebrovascular accident Without treatment, the patient in hypertensive crisis may incur cardiac and renal damage Death may ensue as a result of a cerebrovascular accident, renal failure, or cardiac failure Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Medical Diagnosis Assessment in the ED reveals elevated blood pressure, pulse, and respiratory rate Retinal hemorrhage or papilledema, or both, observed in fundus (back, interior portion) of eye Physician may order blood drawn for arterial blood gases, CBC, electrolytes, blood urea nitrogen, creatinine, and cardiac enzymes Chest radiograph may be requested Direct blood pressure monitoring through an arterial catheter preferred Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Medical Treatment The goal of drug therapy is to rapidly reduce the pressure to a non–life-threatening level and then to bring it slowly within normal range Diuretics and potent vasodilators Fenoldopam Nitroglycerin Diazoxide Hydralazine Phentolamine Labetalol Nitroprusside Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Medical Treatment (cont.) An intravenous line is usually established because many drugs are given by that route Oral options for the management of hypertensive crisis include captopril, clonidine, and nifedipine See Box 38-3 Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Assessment Frequently check blood pressure, pulse, respiration, and level of consciousness Some drugs are given in intravenous fluids, requiring continuous monitoring and adjustment Careful record of fluid intake and output Nausea and vomiting may indicate an impending seizure or coma Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Interventions Administer prescribed drugs Vital signs before and after each dose Monitor cardiac and renal function Start and maintain intravenous therapy Administer oxygen as ordered Comfort the patient Copyright © 2016 by Saunders, an imprint of Elsevier Inc.

Copyright © 2016 by Saunders, an imprint of Elsevier Inc. Interventions (cont.) Take appropriate safety measures if the patient shows signs of seizure activity or a decreasing level of consciousness Once patient’s condition improves, it is important to explain how to manage hypertension and prevent future crises What safety measures should be taken for signs of seizure activity or decreased consciousness? Copyright © 2016 by Saunders, an imprint of Elsevier Inc.