Hypertension PDF

10/17/23, 4:05 PM Realizeit for Student Hypertension Hypertension is the most common chronic disease among adults in the United States and in the world (Whelton, Carey, Aronow, et al., 2017). It is identified as the leading risk factor for premature death, disability, and overall disease burden wo...

10/17/23, 4:05 PM Realizeit for Student Hypertension Hypertension is the most common chronic disease among adults in the United States and in the world (Whelton, Carey, Aronow, et al., 2017). It is identified as the leading risk factor for premature death, disability, and overall disease burden worldwide because it may lead to cardiovascular disease (CVD), stroke, and chronic kidney disease (CKD) when not appropriately treated (Caillon, Paradis, & Schiffrin, 2019; DePalma, Himmelfarb, MacLaughlin, et al., 2018). The overall risk of developing these CVDs, strokes, and renal disorders is low among patients with blood pressures that are consistently stable around 115/75 mm Hg; however, each increase of 20 mm Hg in the systolic blood pressure (SBP) or 10 mm Hg increase in the diastolic blood pressure (DBP) doubles the risk of death from stroke or heart disease (Lee, Kim, Kang, et al., 2018). And yet, most patients with hypertension could lower their blood pressure through lifestyle changes (e.g., diet, exercise, medication adherence, smoking cessation) and lower these associated morbid risks (Whelton et al., 2017). This module presents an overview of hypertension and how it is defined and managed so that nurses may appropriately assess, monitor, educate, and intervene with patients with hypertension. For many years, patients were diagnosed with hypertension if they had chronically elevated SBPs of 140 mm Hg or higher or DBPs of 90 mm Hg or higher. These parameters, which also specified that the diagnosis of hypertension must be based on an average of two or more accurate readings taken one to 4 weeks apart, were endorsed by the Seventh Report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure (JNC 7) (Chobanian, Bakris, Black, et al., 2003), as well as the Eighth Joint National Committee (JNC 8) (James, Oparil, Carter, et al., 2014), and the American Society of Hypertension (ASH) and the International Society of Hypertension (ISH) (Weber, Schiffrin, White, et al., 2014). However, these parameters for diagnosing hypertension recently changed to less permissive parameters, and patients with average SBPs that are 130 mm Hg or higher or with average DBPs 80 mm Hg or higher may be diagnosed with hypertension, according to the American College of Cardiology (ACC)/American Heart Association (AHA) Task Force (Whelton et al., 2017). The classification system for hypertension has been further revised by the ACC/AHA (Whelton et al., 2017) to include elevated, stage 1, and stage 2 categories, as displayed in Table 27-1. Table 27-1 compares this classification system to previous JNC 7 and JNC 8 guidelines classification systems, which are no longer followed (DePalma et al., 2018). The blood pressure categories emphasize the direct relationship between the SBP and DBP risks of morbidity, allcause mortality, and specifically, cardiovascular mortality. Of particular note, the ACC/AHA guideline (Whelton et al., 2017) changed the previously labeled prehypertension category to elevated blood pressure category. The rationale for this change in terminology is to highlight the https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IWsgl87YCND5MlxcaDR%2bIXwVK92JaTnVop0r%2bp7eT… 1/6 10/17/23, 4:05 PM Realizeit for Student association between any elevated blood pressure and increased cardiovascular risk. The blood pressure readings should use the average of two or more valid, reproducible measurements obtained on more than two occasions, in most instances (see later discussion under Assessment and Diagnostic Findings). The prevalence of hypertension among adults in the United States is substantially higher when the definition of the ACC/AHA guideline is used versus the JNC 7 or JNC 8 definition (46% vs. 32%) (Whelton et al., 2017). However, since nonpharmacologic treatment (i.e., lifestyle changes) is recommended for most adults whose blood pressures are within the elevated hypertension category, the newer guidelines that define hypertension have resulted in only a small increase in antihypertensive medication prescriptions, overall. Indeed, it has been asserted that the greatest benefit of the ACC/AHA (2017) guideline is its greater emphasis on lifestyle interventions, which include weight loss, healthy diet, physical exercise, reduced sodium intake, increased potassium intake, and decreased alcohol intake (Ioannidis, 2018). https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IWsgl87YCND5MlxcaDR%2bIXwVK92JaTnVop0r%2bp7eT… 2/6 10/17/23, 4:05 PM Realizeit for Student The prevalence of hypertension increases as people age or have other cardiovascular risk factors. Of all adults with hypertension, it is estimated that 35.3% do not know that they have this disorder. Furthermore, approximately 45.4% of people with hypertension do not have their blood pressure under control (Benjamin, Muntner, Alonso, et al., 2019). The prevalence of hypertension varies by ethnicity and gender, and is estimated at approximately 48.2% among Caucasian men, 41.3% among Caucasian women, 58.6% among African American men, 56% among African American women, 47.4% among Hispanic men, 40.8% among Hispanic women, 46.4% among Asian American men, and 36.4% among Asian American women. The prevalence of hypertension among African Americans is among the highest in the world (Benjamin et al., 2019). Moreover, African Americans tend to develop hypertension at younger ages than Caucasian Americans (Spikes, Higgins, Quyyumi, et al., 2019). Chart 27-1 displays risk factors for hypertension. Findings from the National Health and Nutrition Examination Survey (NHANES) have shown better hypertension control rates in women, in Caucasians than in African Americans and Hispanics, and in older versus younger patients. Additionally, adults of higher socioeconomic status have better control of their blood pressures compared to adults of lower socioeconomic status. Hypertension is most prevalent among adults 75 years of age and older, affecting 80% of men and 85.6% of women (Benjamin et al., 2019). Hypertension is categorized as either primary hypertension or secondary hypertension. Primary hypertension (also called essential hypertension) is diagnosed when there is no identifiable cause (Alexander, 2019). Approximately 90% to 95% of adults with hypertension have primary hypertension. Secondary hypertension is defined as high blood pressure from an identifiable underlying cause. Between 5% and 10% of all adults with hypertension have secondary hypertension. Screening for secondary hypertension is indicated for new-onset, poorly controlled hypertension, in hypertension resistant to treatment with three or more drugs, with hypertension of an abrupt onset, or in patients younger than 30 years of age. In addition, a new diagnosis of hypertension with associated excessive target organ damage, such as cerebral vascular disease, retinopathy, left ventricular hypertrophy (LVH), heart failure with preserved ejection fraction, coronary artery disease, CKD, or peripheral arterial disease, could suggest secondary hypertension. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IWsgl87YCND5MlxcaDR%2bIXwVK92JaTnVop0r%2bp7eT… 3/6 10/17/23, 4:05 PM Realizeit for Student Pathophysiology Blood pressure is the product of cardiac output multiplied by peripheral resistance. Cardiac output is the product of the heart rate multiplied by the stroke volume. Each time the heart contracts, pressure is transferred from the contraction of the myocardium to the blood and then pressure is exerted by the blood as it flows through the blood vessels. Hypertension can result from increases in cardiac output, increases in peripheral resistance (constriction of the blood vessels), or both. Increases in cardiac output are often related to an expansion in vascular volume. Although no precise cause can be identified for most cases of hypertension, it is understood that hypertension is a multifactorial condition. Because hypertension can be a sign, it is most likely to have many causes, just as fever has many causes (Norris, 2019). For hypertension to occur there must be a change in one or more factors affecting peripheral resistance or cardiac output. In addition, there must also be a problem with the body’s control systems that monitor or regulate pressure (Fig. 27-1). Hypertension is thought to occur as a result of a complex interaction between behavioral– social–environmental risks and genetics (Zilbermint, Gaye, Berthon, et al., 2019). Behavioral– social–environmental risks may include dietary habits, including limited consumption of vegetables, fiber, fish fats, and potassium, and excessive intake of sodium; obesity; poor physical fitness; and excessive alcohol intake (Whelton et al., 2017). Although single-gene mutations associated with hypertension have been identified, most types of hypertension are thought to be polygenic (i.e., mutations in more than one gene) (Whelton et al., 2017). The tendency to develop hypertension can be inherited; however, genetic profiles alone cannot predict who will and will not develop hypertension. The role of genetics in hypertension is complex and not fully understood at the present time. To date, over 1000 genetic variants have been identified that may contribute to hypertension; however, collectively they explain only about 6% of the trait variance (Zilbermint et al., 2019). Many physiologic precedents that can lead to hypertension have been identified (Caillon, Mian, Fraulob-Aquino, et al., 2017; Caillon et al., 2019; Norris, 2019): Increased sympathetic nervous system activity related to dysfunction of the autonomic nervous system. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IWsgl87YCND5MlxcaDR%2bIXwVK92JaTnVop0r%2bp7eT… 4/6 10/17/23, 4:05 PM Realizeit for Student Fig. 27-1 Central and reflex mechanisms involved in the neural control of blood pressure. Dotted arrows represent inhibitory neural influences, and solid arrows represent excitatory neural influences on sympathetic outflow. ACH, acetylcholine; Ang II, angiotensin II; EPI, epinephrine; NE, norepinephrine; NTS, nucleus tractus solitarius. Adapted from Kaplan, N. M., & Victor, R. G. (2015). Kaplan’s clinical hypertension (11th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IWsgl87YCND5MlxcaDR%2bIXwVK92JaTnVop0r%2bp7eT… 5/6 10/17/23, 4:05 PM Realizeit for Student https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IWsgl87YCND5MlxcaDR%2bIXwVK92JaTnVop0r%2bp7eT… 6/6