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Chapter 37 Hypertension Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 1 Learning Objectives • • • • • • • Define hypertension. Explain the physiology of blood pressure regulation. Discuss the risk factors, signs and symptoms, diagnosis, treatment, and complications of hypertension. Identify the nursing considerations when administering selected antihypertensive drugs. List the data to be collected for the nursing assessment of a person with known or suspected hypertension. Identify the nursing diagnoses, goals, and outcome criteria for the patient with hypertension. Describe the nursing interventions for the patient with hypertension. Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 2 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 37-1 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 3 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 4 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 5 Anatomy and Physiology of Blood Pressure Regulation • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 6 Anatomy and Physiology of Blood Pressure Regulation • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 7 Anatomy and Physiology of Blood Pressure Regulation • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 8 Anatomy and Physiology of Blood Pressure Regulation • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 9 Figure 37-1 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 10 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 11 Primary (Essential) Hypertension Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 12 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 13 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 14 Figure 37-2 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 15 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 16 Complications • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 17 Diagnostic Tests and Procedures • Confirmed by repeated findings of average pressures equal to or greater than 140/90 • Ambulatory blood pressure monitors • Physician 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 18 Medical Treatment • Lifestyle modifications • • • • • Weight reduction Smoking cessation Sodium and alcohol restriction Exercise Relaxation techniques Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 19 Medical Treatment • Pharmacologic therapy • Specific antihypertensive drugs • • • • • • • • Diuretics Beta-adrenergic receptor blockers Calcium antagonists Angiotensin-converting enzyme (ACE) inhibitors (or ACEIs) Angiotensin II receptor antagonists (ARBs) Central adrenergic blockers Alpha-adrenergic receptor blockers Direct vasodilators Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 20 Figure 37-3 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 21 Medical Treatment • Pharmacologic therapy • Nursing implications • Administering the drugs to inpatients • Monitoring for therapeutic and adverse effects • Teaching patients about their drugs Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 22 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 23 Nursing Care of the Patient with Hypertension Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 24 Assessment • Periodic blood pressure checks detect new or unknown hypertensive people; provide data to evaluate effect of therapy in hypertensive people • Complete history and physical examination by the registered nurse • The LVN may be involved in initial blood pressure screenings and monitoring, and provides important data to evaluate treatment effectiveness Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 25 Health History • Explore past medical for hypertension or renal, cardiac, or endocrine disorders • Date and readings of the last blood pressure measurement • Ask about pregnancy and about hormone replacement therapy • Current medications, including over-thecounter drugs Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 26 Health History • Family health history: hypertension, myocardial infarction, or cerebrovascular accidents • Body systems for signs and symptoms, particularly headaches, epistaxis, dizziness, visual disturbances, dyspnea, angina, nocturia • Data about the patient’s usual functioning may detect some risk factors for hypertension • Occupation, exercise and activity, sleep and rest, nutrition, interpersonal relationships, and stressors Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 27 Physical Examination • General appearance; note obvious distress • Measure height and weight and vital signs • Patient should be seated in a chair with feet on the floor and arm resting at the level of the heart • The proper cuff size is essential • Multiple readings should be taken • Blood pressure assessed in both arms in the supine, sitting, and standing positions Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 28 Interventions: Ineffective Therapeutic Regimen 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 29 Interventions: Ineffective Therapeutic Regimen Management • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 30 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 31 Interventions • Ineffective Coping • If depression a side effect of an antihypertensive, consult physician to substitute another drug • Sexual Dysfunction • Decreased libido, inability to achieve an erection, or delayed ejaculation • Advise physician so an alternative medication or other intervention can be considered Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 32 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 33 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 34 Hypertensive Emergencies • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 35 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 36 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 37 Medical Treatment • 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 37-3, p. 728 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 38 Nursing Care of the Patient in Hypertensive Crisis Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 39 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 40 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 41 Interventions • 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 Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc. 42