2. Hypertension: Definition
Persistent elevation of
Systolic blood pressure ≥140 mm Hg
or
Diastolic blood pressure ≥90 mm Hg
• Worldwide an estimated 1 billion people have
hypertension; about 1 in 3 Americans affected
• Direct relationship between hypertension and
cardiovascular disease (CVD)
4. Hypertension
• It is estimated that 1/3 of the general population in the US have
hypertension (Fields et al, 2004)
• Healthy People 2010: reduce the # of persons with HTN by
14%, increase the control of BP by 68%, increase the # of adults
taking action by weight loss, activity, low sodium diet by 98%
and increase the proportion of adults measuring their BP by
95%
• Risk of hypertension increases with age; if you don’t have it by
age 55 – 90% chance of getting it later in life
• CVD is #1 cause of death in women in US & other developed
areas of world; < 50% of women are aware of this fact See p.
762 for box at top of page with gender differences &
hypertension; Before age 55 hypertension more common in men
and they have MIs > 55 yrs, hypertension more common in
women and they have strokes
7. Sympathetic Nervous System
• Baroreceptors
Nerve cells in carotid artery & aortic arch
Maintain BP during normal activities
React to increases & decreases in BP
• BP – impulse to brain to inhibit SNS; HR
& force of ctrx; vasodilation of arterioles
• BP – activates SNS; vasoconstriction of
arterioles; HR & heart contractility
8. • Increased BP send inhibitory
impulse to sympathetic vasomotor
center in brainstem;
• In long-standing hypertension,
baroreceptors adjust to elevated BP
and reads it as normal; doesn’t make
adjustments; also becomes less
responsive in some older adults
9. Mechanism of Action of Aldosterone
Fig. 33-2
Increases CO by increasing blood volume
.
11. Etiology of Hypertension
• Primary (essential or idiopathic)
hypertension
Elevated BP without an identified
cause
90% to 95% of all cases
12. Etiology of Hypertension
• Primary (essential or idiopathic)
hypertension
Contributing factors
• ↑ SNS activity
• ↑ Sodium retaining hormones and
vasoconstrictors
• Diabetes mellitus
• > Ideal body weight
• ↑ Sodium intake
• Excessive alcohol intake
13. Secondary Hypertension
Elevated BP with a specific cause
• 5% to 10% of adult cases
Contributing factors:
• Coarctation of aorta name given to a congenital condition whereby the aorta
narrows in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts.
• Renal disease
• Endocrine disorders
• Neurologic disorders
• Cirrhosis
• Sleep apnea
If someone under 20 or over 50 suddenly develops
hypertension, esp. severe then suspect secondary cause
14. Risk Factors for - Primary Hypertension
• Age (>55)
• Alcohol
• Cigarette smoking
• Diabetes mellitus
• Elevated serum lipids
• Excess dietary sodium
• Gender
SBP rises with age Alcohol – excessive use strongly correlated to
hypertension
Smoking – increases risk for CV disease ; vasoconstriction
Diabetes – along with hypertension greater risk for target organ disease and
usually more severe
Hyperlipidemia elevated in people with hypertension; increases risk of
atherosclerosis
Some pts Na sensitive Males have higher rates of hypertension <55 and
increased in women>55
15. Risk Factors for
Primary Hypertension
• Family history
• Obesity
• Ethnicity
• Sedentary lifestyle
• Stress
16. Pathophysiology of
Primary Hypertension
• Heredity
In most cases, hypertension results from
the interaction of:
• Environmental factors
• Demographic factors
• Genetic factors
17. Primary Hypertension
• Water and sodium retention
A high sodium intake may result in water
retention
Some people are Na sensitive (about
20%) ; not everyone with high salt diet
develops hypertension
18. Pathophysiology of
Primary Hypertension
• Water and sodium retention
Certain demographics are associated
with “salt sensitivity”
• Obesity
• Increasing age
• African American ethnicity
• People with diabetes, renal disease
19. Pathophysiology of
Primary Hypertension
• Stress and increased SNS activity
Produces increased vasoconstriction
↑ HR
↑ Renin release
Angiotensin II causes direct arteriolar
constriction, promotes vascular hypertrophy and
induces aldosterone secretion
20. Pathophysiology of
Primary Hypertension
• Insulin resistance & hyperinsulinemia
High insulin concentration stimulates SNS
activity and impairs nitric oxide–mediated
vasodilation
Not present in secondary hypertension and
don’t improve when hypertension is treated
21. Pathophysiology of
Primary Hypertension
• Altered renin–angiotensin mechanism
High plasma renin activity
• Endothelial cell dysfunction
Source of many vasoactive substances
Role of endothelial cell dysfunction in cause and
treatment of hypertension is ongoing
22. • Renin is an enzyme released by the kidney to help control the body's
sodium-potassium balance, fluid volume, and blood pressure.
• Description
• When the kidneys release the enzyme renin in response to certain
conditions (high blood potassium, low blood sodium, decreased blood
volume), it is the first step in what is called the renin-angiotensin-
aldosterone cycle. This cycle includes the conversion of
angiotensinogen to angiotensin I, which in turn is converted to
angiotensin II, in the lung. Angiotensin II is a powerful blood vessel
constrictor, and its action stimulates the release of aldosterone from
an area of the adrenal glands called the adrenal cortex. Together,
angiotensin and aldosterone increase the blood volume, the blood
pressure, and the blood sodium to re-establish the body's sodium-
potassium and fluid volume balance. Primary aldosteronism, the
symptoms of which include hypertension and low blood potassium
(hypokalemia), is considered "low-renin aldosteronism."
23. Hypertension
Clinical Manifestations
• Referred to as the “silent killer”
• Frequently asymptomatic until target
organ disease occurs
Or recognized on routine screening
24. Hypertension
Clinical Manifestations
• Sx often secondary to target organ
disease
• Can include:
Fatigue, reduced activity tolerance
Dizziness
Palpitations, angina
Dyspnea
26. Hypertension
Complications
• Hypertensive
heart disease
Coronary artery
disease
Left ventricular
hypertrophy
Heart failure
Increased systemic vascular resistance causes left ventricle to work to hard;
initially increases in size as compensatory mechanism; eventually becomes
too large and requires more oxygen and energy; can’t keep up with demand Fig. 33-3: Top, normal
and end up with heart failure heart; Bottom, left
ventricular hypertrophy
27. Hypertension-Complications
• Cerebrovascular disease
Stroke
• Peripheral vascular disease
• Nephrosclerosis
• Retinal damage
• Atherosclerosis most common cause of cerebrovascular disease;
hypertension major risk factor for cerebral atherosclerosis and stroke
• Atherosclerosis in peripheral blood vessels too; can lead to PVD, aortic
aneurysm, aortic dissection
• Hypertension one of leading causes of end-stage renal disease, esp. in
African-Americans; some degree of renal dysfunction usual in person with
even mild BP elevations
• Retina is only place blood vessels can be directly visualized; if see damage
there then indicates damage in brain, heart, & kidney too; Can cause
blurring, retinal hemorrhage and blindness
28. Hypertension
Diagnostic Studies
• History and physical examination
• BP measurement in both arms
Use arm with higher reading for subsequent
measurements
BP highest in early morning, lowest at
night
29. Hypertension
Office BP Measurement
• Use auscultatory method with a properly calibrated
instrument
• Patient seated quietly for 5 min in a chair, feet on the floor,
and arm supported at heart level
• Appropriate-sized cuff is necessary to ensure accurate reading
• At least two measurements should be obtained
• Allow at least 1 minute between readings. If one arm higher
than other; take BP in higher arm for subsequent
measurements
30. Hypertension
Diagnostic Studies
• Urinalysis, creatinine clearance
• Serum electrolytes, glucose
• BUN and serum creatinine
• Serum lipid profile
• ECG
• Echocardiogram
• Know normal lab values! Use your lab book
31. Hypertension
Diagnostic Studies
• “White coat” phenomenon may precipitate the need
for ambulatory blood pressure monitoring (ABPM)
Noninvasive, fully automated system that
measures BP at preset intervals over a 24-hour
period
Also used when suspect drug resistance,
hypotensive symptoms with drug therapy,
episodic hypertension, or SNS dysfunction
32. Hypertension
Collaborative Care
• Overall goals
Control blood pressure
Reduce CVD risk factors
• Strategies for adherence to regimens
Empathy increases patient trust, motivation,
adherence to therapy
Consider patient’s cultural beliefs, individual
attitudes in formulating treatment goals
33. Benefits of Lowering BP
Average Percent Reduction
Stroke incidence 35%–40%
Myocardial infarction 20%–25%
Heart failure 50%
34. Collaborative Care
Lifestyle Modifications
• Wt. reduction
10 kg (22 lb) loss; SBP by 5-20 mm Hg
• DASH eating plan (dietary approaches to stop
hypertension)
• Na reduction
<2.4 g of sodium/day
• Moderate alcohol intake
Men: 2 drinks/day or less
Women: 1 drink/day or less
35. Collaborative Care
Lifestyle Modifications
• Physical activity:
Regular physical (aerobic) activity,
At least 30 min, most days of week
• Avoidance of tobacco products
• Stress management
36. Collaborative Care HTN
Drug Therapy
• Primary actions
Reduce SVR
Reduce volume of circulating blood
• Classifications
Diuretics
Adrenergic inhibitors
Direct vasodilators
Angiotensin inhibitors
Calcium channel blockers
• Review pharmacology and know drug classes & how they
work to reduce BP; side effects
• See pps 773-776 in book for good overview!!!
39. Collaborative Care
Drug Therapy
• Patient teaching
Identify, report, minimize side effects to
enhance compliance
• Orthostatic hypotension
• Sexual dysfunction
• Dry mouth
• Frequent urination
40. Collaborative Care
Nursing Management
Assessment
Subjective data
• Past health history
• Medications
• Functional health patterns
Objective data
• Target organ damage
41. Collaborative Care
Nursing Management
Nursing Diagnoses
• Ineffective health maintenance
• Anxiety
• Sexual dysfunction
• Ineffective therapeutic regimen management
• Disturbed body image
• Ineffective tissue perfusion
43. Collaborative Care
Nursing Management
Planning
• Patient will:
Achieve & maintain individually determined
goal BP
Understand, accept, & implement therapeutic
plan
Experience minimal/no unpleasant side effects
of therapy
Be confident of ability to manage & cope with
condition
45. Collaborative Care
Nursing Management
Implementation
Ambulatory and Home Care
Patient/family teaching:
• Nutritional therapy
• Drug therapy
• Physical activity
• Home monitoring of BP (if appropriate)
• Tobacco cessation (if applicable)
46. Collaborative Care
Nursing Management
Nursing Evaluation
• Patient will:
Achieve & maintain goal BP as defined for the
individual
Understand, accept, and implement the
therapeutic plan
Experience minimal or no unpleasant side
effects of therapy
47. Hypertension in Older Persons
• Isolated systolic hypertension (ISH):
Most common form of hypertension in people
> 50 years of age
• Lifetime risk of developing hypertension:
About 90% for normotensive men and women over age 55
• Reasons for increased BP in elderly:
Loss of elasticity
Increased collagen and stiffness of myocardium
Increased PVR
Decreased adrenergic receptor sensitivity
Blunting of baroreceptor reflexes
Decreased renal function
Decreased renin response to Na/H2O depletion
May have altered drug absorption; delayed metabolism and excretion; be
careful when medicating
48. Hypertension in Older Persons
• More likely to have “white coat”
hypertension
• Often a wide gap between 1st Korotkoff
sound and subsequent beats called the
auscultatory gap
Failure to inflate the cuff high enough
may result in seriously underestimating
the SBP
49. Hypertension in Older Persons
• Have varying degrees of impaired
baroreceptor reflex mechanisms
• Consequently, orthostatic hypotension
occurs often
Especially in patients with ISH
50. Cultural and Ethnic Disparities
• In general, Trx similar for all
demographic & ethnic groups
• Prevalence & severity of HTN
increased in African Americans
51. Cultural and Ethnic Disparities*
• Mexican Americans less likely to receive
treatment than whites & African
Americans
• Mexican Americans & Native Americans
have lower rates of BP control than whites
and African Americans
52. Hypertensive Crisis
• Severe, abrupt increase in DBP
Defined as >140 mm Hg
• Rate of increase in BP more important than absolute
value
• Often occurs in patients with Hx of HTN who failed to
comply with medications or who have been
undermedicated
• Monitor MAP mean arterial pressure: MAP = (SBP + 2DBP)
3
54. Hypertensive Crisis
Nursing & Collaborative Management
• Hospitalization
IV drug therapy: Titrated to mean arterial pressure
Monitor cardiac and renal function
Neurologic checks
Determine cause
Education to avoid future crises
• Decrease BP by no more than 25% within 1st hr; then if
stable goal for BP is 190/100 over next 2-6 hrs
• Lowering BP too much or too quickly increases risk for
stroke, MI, renal failure due to decreased perfusion to these
vital organs
55. Hypertensive Emergency
• Develops over hours-days
• BP > 180/120 mm Hg
• Evidence of acute target organ damage, esp. to CNS
Hypertensive encephalopathy
Sx may be similar to stroke, but no focal or lateral signs
• Can see sudden rise in BP with HA, N&V, SZ, confusion,
stupor & coma; Increased ICP due to edema
• Common to have blurred vision and transient blindness
• Renal insufficiency to complete shutdown
• Rapid cardiac decompensation; MI, dyspnea
56. Hypertensive Urgency
• Develops over days to weeks
• BP severely elevated but no evidence of
target organ damage
Usually treat with oral meds as outpatient
57. Supporting Materials
• Web site www.nhlbi.nih.gov
• For patients and the general public
Facts about the DASH Eating Plan
Your Guide to Lowering Blood Pressure
My Blood Pressure Wallet Card
• For health professionals
Reference Card