chapter 40 HTN

Question 1

baroreceptors regulating BP

Answer 1

• located in carotid and aortic arch, sense change in BP via stretching
• send inhibitory signals to SNS reducing HR, decreased contraction of hrt, and peripheral vasodilation
• increases PNS reducing HR via vagus nerve
• works well during normal activities but longstanding HTN resets receptors as to what to accept as “normal”
• diminished response of barorecptors are effect of aging and lifetime risk of HTN

Question 2

endothelial factors influencing BP

Answer 2

• has ability to produce vasoactive substances and growth (i.e. nitric oxide)
• can produce vasodilators and vasoconstrictors (growth)
• growth associated with atherosclerosis-can be due to dysfunction of endothelial

Question 3

kidneys as BP regulators

Answer 3

• controls by RAAS
• renin secreted by juxtaglomerular apparatus converts angiotensinogen to angiotensin I
• angiotensin I converted to angiotensin II by ACE in lungs
• angiotensin II effects BP by: vasoconstriction-increasing peripheral vascular resistance; stimulates aldosterone which promotes Na+ and H2O retention–increasing volume; stimulates growth of vascular smooth muscle and may contribute to atherosclerosis

Question 4

workup for HTN

Answer 4

• EKG
• U/A
• blood glucose
• serum K+, creatinine, Ca+
• lipid profile
• C-reactive protein
• homocysteine

Question 5

classifications of HTN

Answer 5

normal: 160/ >100 lifestyle changes, 2 drug combo for most–thiazide and ACE/ARB/BB/CB

Question 6

stepped therapy

Answer 6

• set appropriate BP goal-no longer below 120/80
• work attaining goal over several weeks
• titrate meds no more frequent than every 4-6 wks
• plan at beginning of tx if to start more than one drug
• tx goal of SBP in older adults but go slower if asymptomatic
• control extracellular fluid volume

Question 7

initial drug therapy

Answer 7

• monotherapy is preferred if able to control HTN
• thiazides first line
• may consider ACE, ARB, CCB, if BP is more than 20 mm Hg above systolic goal of 10 mm Hg of diastolic goal

Question 8

stepping up to multiple drugs

Answer 8

• do not wait until full dose of first drug fails–if BP not controlled: add second drug or substitute drug for another class
• choose second drug based on being different and action of first drug

Question 9

children and adolescents

Answer 9

• definition of HTN takes in to account age and height by sex
• chronic HTN associated with obesity, lifestyle, family history
• ACE and ARBs do not prescribe for girls who are sexually active–teratogenic effects

Question 10

older adults

Answer 10

• goal of tx similar to younger adults
• combo of thiazide and potassium sparing diuretic useful for pt. with repeated hypokalemia
• be careful of orthostatic hypotension
• chronic HTN can lead to cognitive dysfunction/dementia-CCB are highly effective in slowing the process

Question 11

women

Answer 11

• highest rate of HTN is black women over age 75
• menopause can effect BP
• oral contraceptive increase BP
• pregnancy-chronic HTN, preeclampsia, gestational HTN, transient HTN–can cause fetal distress

Question 12

pathophysiology

Answer 12

-any factor producing sustained alterations in vascular resistance, heart rate, stroke volume affects systemic arterial pressure