lecture htn

7/29/2019 Lecture HTN

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Cardiovascular Dysfunction

Part one: HYPERTENSION


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What is hypertension?

Sustained systolic pressure greaterthan 140mm Hg and diastolic

pressure greater than 90mm Hg

Based on more than one bloodpressure measurement taken at

different times.


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Classification of HTN

JNC VII report now redefines bloodpressure stages

Refer to handout regarding

classifications


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Types of Hypertension

Primary or essential hypertension-thereason for the increased blood

pressure cannot be identified

Secondary-elevated blood pressurefrom an identified cause


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Is HTN always a disease?

Elevated BP may be-a vital sign that is routinely monitored as part of

clinical status

Risk factor for atherosclerosis(plaques accumulate on arterial walls

also called hardening of the arteries)

Disease that contributes to death fromcardiac, renal and peripheral vascular

disease


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Pathophysiology

Blood pressure (BP) equals cardiacoutput (CO) times peripheral

resistance (PR)

BP= CO X PR Hypertension equals increased CO

and/or increased PR (figure 32-1,

page 857)


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What is cardiac output?

CO is the volume of blood flowingthrough either the systemic or the

pulmonary circuit per minute. This

blood flow exerts pressure on thewalls of arteries.

It is effected by sodium intake, fluid

volume, venous constriction andstress


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Peripheral resistance

Resistance to blood flow within thearteries and arterioles.

The smaller the diameter of the

vessel, the greater the resistance.The larger the diameter the less the

resistance.

It is influenced by obesity,sympatheticnervous system activity, hormonal

substances and other factors (p.819)


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Preload and Afterload

Preload determined by the volume ofthe blood within the ventricle at the

end of diastole. It is the degree of

stretch by the cardiac fibers at theend of diastole.

Afterload is the amount of resistance

to ejection of blood from the ventricle(SVR)


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Aging and blood pressure

Isolated systolic hypertension iscommon in the elderly.

Problems associated with aging

cause a decrease in the elasticity ofmajor blood vessels.

Force of the blood that would have

caused the vessels to stretch, nowraises the blood pressure.


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May be asymtomatic-silent killer Retinal changes-cotton wool spots,

papilledema

Target organ damage-heart, kidneysand cerebrovascular system

Symptoms anyone?


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What is target organ damage?

Major vessels affected byhypertension:

Heart-CAD (angina, MI, heart failure)

Kidneys- renal failure (nocturia)

Cerebrovascular- TIAs, stroke

Peripheral vascular disease

Eyes-retinopathy


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Diagnosing hypertension

Health history and physical exam Eye exam-particularly the retinas

Risk factor assessment

Laboratory studies

-urinalysis and blood chemistry (Na,

K, creatinine, fasting glucose,

cholesterol, LDL, HDL)-12 lead EKG

-Echocardiogram


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Routine lab work is a base line andmay indicate a problem for further

study -elevated LDL in

atherosclerosis Renal damage is assessed by protein

in urine and elevated BUN and

creatinine levels Echocardiogram can diagnose

ventricular hypertrophy

Lab data


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Goal of treatment

To achieve and maintain the patientsBP below 140/90 in order to prevent

complications and death.

To provide care that is inexpensive,simple and causes the least possible

disruption in the patients life.


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Treatment recommendations

Lifestyle modifications-weight loss

-reduce alcohol and sodium intake

-regular physical activity

-diet high in fruits and vegetables-stop smoking

-reduce saturated fat and cholesterol

-maintain adequate intake of K, Ca,

and Mag


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If lifestyle change isnt

enough, then what?

Medications to reduce the bloodpressure are then ordered. There are

several types which function

differently. -diuretics-Andrenergic Inhibitors-Beta-blockers

-Alpha- blockers

-vasodilators

-Angiotension-

converting enzyme inhibitors

-Angiotensin II receptor blockers-


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Medications cont

Calcium channel blockers Peripheral vasodilators

H d di i k


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How do diuretics work to

lower the blood pressure?

Primary action is in the kidney-decrease blood volume

-decrease the reabsorption of Na and water

-decrease cardiac output

-increase renal blood flow

May be one of three types

-thiazide

-loop-potassium sparing

Ad i i hibit


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Adrenergic inhibitors vs.

diuretics

Adrenergic inhibitors work onnorephinephrine (increases the BP)

-impairs synthesis and reuptake of

norephinephrine -prevents release of

norephinephrine -decreases stores

of norephinephrine

Includes Catapres, Aldomet, Serpasil


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A&Bs of blockers

Beta-blockers-block sympatheticnervous system (beta-adrenergic

receptors) Inderal and Lopressor- slower heart rate-lower blood pressure

Alpha-blockers-peripheral

vasodilation directly to blood vessel

(Minipress) - lowers blood pressure


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Vasodilators for control?

Vasodilators-work on smooth muscleof arterial vessels

- decrease peripheral resistance

- reduces systolic and diastolic blood

pressure - peripheral vasodilation

Includes Apresoline, nitroglycerin, Nitropres


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Angiotensin

Angiotensin is a polypeptide in theblood that causes BP to elevate.

- angiotensin-converting enzyme inhibitors

prevent converion of angiotensin I to angiotensin II

(Capoten and Vasotec)

- angiotensin II receptor blockers-

block effects of angiotensin II at the receptor

(Cozaar and Diovan)


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Anticholinergic effects Effects on electrolytes

GI symptoms

Postural hypotension

Sexual dysfunction

Mental depression-see medication handoutfor hypertension

Side effects of meds


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BP checks

Screening- routine monitoring of all patients (may be

asymtomatic)

Initial Detection- regular intervals

Monitor effects of treatment regimen

- routinely scheduled intervals to determine if

treatment is working and to determine if changes

need to be made in treatment


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Assessment

Nurse also needs to assess- complete history (especially symptoms that

may indicate target organ damage)

- physical exam (rate, rhythm and character

of apical and peripheral pulses)


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Nursing diagnoses

Knowledge deficit regarding therelation between treatment regimen

and control of the disease process.

Noncompliance with the therapeuticregimen related to side effects of

prescribed therapy


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Other problems?

Collaborative Problems/potentialcomplications

- left ventricular hypertrophy

- myocardial infarction

- heart failure

- TIAs

- Stroke

- Renal insufficiency and retinal

hemorrhage


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Major nursing goals

Major goals/outcomes- patient will develop an

understanding of the disease process and its

treatment - patient will

participate in a self-care program - patientwill be free from complications of hypertension


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Interventions

1. Increase patients knowledge- explain what hypertension is

- explain how hypertension is treated (lifestyle

modifications and medication regimen)

- explain physician and nurses role- explain patients role


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Interventions continued

2. Teach and support Self-Care- lifestyle modifications are

- weight loss

- reduce alcohol consumption

- quit smoking- support groups for weight,

smoking and stress - exercise regimen

- stress management


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Nursing Interventions

2. Teach and support self-care cont- medications

- what, when, how

- expected results, side effects

- Self monitoring of BP- Follow-up with health care

professional


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Nursing Interventions

3. Monitor clinical status- routinely check BP and vital signs

- routinely check lab data

- administer prescribed medications (client

response and adverse reactions)- monitor for target organ problems


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Evaluation of Outcome #1

Knows normal & abnormal values ofBP

Knows the need to modify diet, take

medications, routinely exercise, quitsmoking, decrease alcohol intake

Knows that doctor/nurse will-inquire

about lifestyle modifications, monitor response tomeds, assess for complications of hypertension,

adjust/add medications as needed


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Knows importance of compliance- lifestyle changes

- medication regimen

- follow-up visits

- reporting effects/side effects


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Knows which lifestyle changes areneeded

- adheres to dietary regimen

- exercise regularly

- quit smoking

- reduce use of alcohol

- attend support groups for weight,

smoking, and stress


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Know what medication she/he istaking - can name them

- knows the expected side effects

- knows when to take, how to take

- knows what side effects to reportto physician - knows not to stop them without

consulting with physician first


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Knows how to take own bloodpressure of knows resources for BP

checks

Has follow-up appointment withphysician

Knows importance of keeping

appointments


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Patient has no complications ofhypertension

- maintains BP and vital signs in normal range

- reports no changes in vision

- exhibits no retinal damage on vision

testing - reports no dyspnea or

edema - results of

renal function tests are normal


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Demonstrates no motor, speech, orsensory deficits

Reports no headache, dizziness,

weakness, changes in gait or falls


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Geriatric treatment

Single medication once a day ifpossible

Schedules to help them remember

when and how to take medications Expense is considered

Involve family


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Noncompliance problems

Acute, life-threatening blood pressureelevations that require prompt

treatment in an intensive care setting

Hypertensive emergency-meds wouldbe by IV-vasodilators that have an

immediate action

Hypertensive urgency


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Hypertensive crisis continued

Hypertensive emergency-BP must belowered immediately to halt or prevent

damage to target organs such as

acute MI, dissecting aortic aneurysmand intracranial hemmorhage

Hypertensive urgency-BP must be

lowered within several hours


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Geriatric considerations

Incidence: Affects 35-45% of elderlyover 65, women>men

Control harder to achieve due to

comorbidities Drug therapy-dosages started low

and increased slowly


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Conclusion

Hypertension-the silent killer-is treatable,but not curable-can sometimes be controlled with

change in lifestyle alone-meds are prescribed from

ones with fewest side effects, least expensive and

reduces BP

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