Week 3 - Hypertension/Hypertensive Crisis Flashcards
what is considered HTN
- SBP >140
- or DBP >90
HTN is a risk factor for…
- CAD
BP is determined by
CO x SVR
what is cardiac output (CO)
- total blood flow thru the systemic or pulmonary circulation per minute
what is SVR
- systemic vascular resistance
= force opposing the movement of blood within blood vessels
what determines SVR
- radius of arteries & arterioles (vasoconstriction & dilation)
- a small change in radius of arterioles = major change in SVR
ex. if SVR is increased but CO remains contstant, BP will increase
what is CO determines by
- stroke volume (amt of blood pumped by the left ventricle per beat) x HR
what are alpha adrenergic receptors located and what do tehy do?
- located in peripheral vasculaure & cause vasoconstriction
where are beta receptors located and what do they do?
- beta 1 = in heart & increase HR, contractility, increased speed of conduction
- beta 2 = in lungs & cause vasodilation
what role does the RAAS have in BP
- renin secreted if decreased blood flow to kidneys, low BP, sympathetic simultation
= angio 2= vasoconstriction
= aldo = keep Na and water
= raised BP
what is isolated systolic HTN
- sustained elevation in SBP >140 but DBP <90
what does isolated systolic HTN result in
- increased pulse pressure (difference between SBP and DBP)
HTN is classified as…
- primary or
- secondary
what is primary HTN
- HTN with an unknown cause
- thought to be complex interaction between genes and enviro
- 90-95% of HTN cases
what are contributing factors for primary HTN (12)
- increased SNS activity
- overproduction of na-retaining hormones & vasoconstrictors
- obesity
- increased sodium intake
- DM
- excessive alcohol intake
- advancing age
- elevated serum lipids
- more prevalent in males
- FHx
- sedentary lifestyle
- stress
what is secondary HTN
- HTN with a specific cause that can be identified and corrected
what are causes of secondary HTN (7)
- renal disease
- endocrine disorders
- neuro disorders
- sleep apnea
- meds
- congential narrowing of aorta
- pregnancy induced
describe what symptoms of HTN are like
- “silent disease” = frequently asymptomatic until it is severe and target-organ disease has occurred
what is target-organ disease
- when pts with HTN experience a variety of symptoms secondary to effects on blood vessels in various organs and tissues , or to the increased workload of the heart
- chronic HTN leads to damage of organs
what organs can HTN effects (5)
- heart
- brain
- kidneys
- eyes
- peripheral vasculature
what symptoms can HTN/target-organ disease cause (6)
- fatigue
- reduced activity intolerance
- dizziness
- palpitations
- angina
- dyspnea
what are common complications of HTN caused by
- caused by target organ disease
what complication can occur in the heart due to HTN (4)
- hypertensive heart disease
- CAD
- heart failure
- left ventricular hypertrophy
how does HTN contribute to CAD
- the shear stress results in endothelial dysfnxn = impairement in synthesis & release of nitric oxide = promote development and acceleration of atheroscleoris and plaque formation
how does HTN cause LV hypertrophy
- sustained high BP = increased cardiac workload = hypertrophy
what does LV hypertrophy leads
- intially, its a compensatory mechanism that strengthens cardiac contraction and increases CO
- then increased contractility increases myocardial work and O2 consumption = heart cannot meet demands = HF
how does HTN lead to HF
- occurs when the heart’s compensatory adaptations are overwhelmed & heart cannot pump enough blood to meet metabolic needs of the body
what complication can occur in the brain d/t HTN (2)
- cerebrovascular disease
- hypertensive encephalopathy
what is cerebrovascular disease
- group of conditions that effect blood flow to the brain
what is the most common cause of cerebrovascular disease
- athersclerosis
what is a major risk factor for cerebral atherosclerosis and stroke
- HTN
what can atherosclerotic plaques in the carotid artery lead to
- can break off and travel to intracerebral vessels = TIA or stroke
when does hypertensive encephalopthy occur
- after a marked rise in BP if the cerebral blood flow cannot be decreased by autoregulation
- autoregulation = physiological process that maintains constant cerebral blood flow despite fluctuation in arterial BP*
what happens in the brain when arterial BP exceeds the body’s ability to autoregulate cerebral blood flow
- cerebral blood vessels suddenly dilate = cerebral edema = increased ICP
what complication can occur in the peripheral vasculature d/t HTN
- peripheral vascular disease
what is peripheral vascular disease? how does HTN lead to this
- a blood circulation disorder that causes the blood vessels outside of your heart and brain to narrow, block, or spasm
- HTN = increased atherosclerosis
what is a classic symptom of peripheral vascular disease
- intermittent claudication = ischemic muscle pain precipitated by activity and relieved w rest
what complication can occur in the kidneys d/t HTN (2)
- nephrosclerosis
- ESRD
how does HTN lead to nephrosclerosis
- direct result of ischemia caused by the narrowed lumen of the intrarenal blood vessels
= eventual death of nephrons
what is a sign of nephrosclerosis (3)
- microalbuminuria
- elevated BUN
- elevated creatinine
what complication occurs in the eyes d/t HTN
- retinal damage
what are signs of retinal damage (3)
- blurred vision
- retinal hemorrhage
- loss of vision
how is HTN diagnosed
- not based on a single elevated BP
- requires severeal elevated BP readings over several weeks
what findings can be used to diagnose HTN (6)
- history
- physical exam
- electrolytes (K+ indicated hyperaldo)
- BG (monitor for development of DM)
- cholestrol and triglyceride lvls
- ECG
what does collaborative care of HTN focus on (3)
- risk stratification
- lifestyle modifications
- meds
what lifestyle modifications are included in treatment of HTN (6)
- dietary changes
- limitation of alcohol intake
- regular physical activity
- avoidance of tobacco use
- stress management
- weight reduction
what is emphasized in nutritional therapy for a pt with HTN (6)
emphasize
- fruit
- veggies
- low-fat dairy
- fibre
- whole grains
- protein
what is reduced in nutritional therapy for a pt with HTN (5)
- sat fats
- cholestrol
- sodium
- maintain K+, Ca, Mg
- calories restriction if overweight
why is weight reduction imp for manageemnt of HTn
- obesity = increased incidence of HTN and increased cardio risk
- weight reduction = signif effect on lowering BP
what weight loss strategies are used for a pt with HTN (3)
- increased physical activity
- behavioral intervention
- decreased cal, na, fat
why is modification of alcohol consumption imp for treatment of HTN
excessive alcohol = strongly associated w HTN
what guidelines are used for alcohol consumption
- 2 drinks or fewer per day
- should not exceed 14 drinks per week for men
- & 9 drinks per week for women
what physical activity guidelines are recommended for pts w HTN
- 30-60 min of moderate intensity exercise, 4-7 days per week
what benefits does physical activity have for a pt with HTN (3)
- lowers BP
- promote relaxation
- decrease/control body weight
why is avoidance of tobacco products imp for treatment of HTN
- nicotine = vasoconstriction = increased BP
what drugs are used in treatment of HTN (5)
- diuretics
- adrenergic inhibitors
- direct vasodilators
- RAAS inhibitors
- Ca channel blockers
what action do diuretics have in reduction of BP (4)
- promote Na and water excretion
- reduce plasma vol
- reduce vascular response to catecholamines
- decrease Na in arteriolar walls
what do adrenergic inhibitors do?
- diminish the sympathetic effects that increase BP
- act centrally on vasomotor center
- inhibit NE release
- block adrenergic receptos on blood vessels
–> alpha and beta blockers
what do direct vasodilators do
- decrease BP by relaxing vascular smooth muscle & cause arteriolar vasodilation by preventing the movement of extracellular Ca into cells
what are 2 examples of direct vasodilators
- nitroglycerin
- nipride
what are 3 types of RAAS inhibitors
- ACE-I
- ARBs
- renin inhibitors
describe how layering meds works for treatment of HTN
- start w first drug at low dose, if BP not controlled in several weeks, dosage increased
- second drug added (or substituted) if the first drug was ineffective or too many s/e (most pts require at least two meds + lifestyle changes)
- third or fourth med may be added but only if the max doses of the first and second drug have been achieved
what is step down therapy
- after 1 year of optimum BP control, step down therapy may be tried
- number and dose of meds is gradually decreases to the lowest amt required to control BP
what is required w step down therapy
- regular follow ups to detect elevations in BP
what are potential s/e of diurectis (5)
- hypokalemia
- hyperglycemia
- hyperuricemia
- polyuria
- dry mouth
what are potential side effects pf ACE-I (3)
- coughing
- angioedema
- hyperkalemia
- may be switched to ARB if experiencing these*
what are 2 potential side effects of adrenergic inhibitors
- orthostatic hypotension
- sexual dysfnxn
what are 2 potential s/e of vasodilators
- orthostatic hypotension
- tachycardia
what is important pt teaching r/t meds (5)
- otrho hypotension –> rise slowly when moving from sitting/laying down to upright position
- encourage to discuss s/e with HCP (esp. sexual dysfunction, as the s/e may be decreased by changing to a diff antiHTN drug)
- sugarless gum can relieve dry mouth r/t diuretics
- take diuretics earlier in day to prevent nocturia
- BP highest after waking up & lowest at night = BP meds with 24 hr duration should be taken eary in morning
what is a major challenge in management of HTN
- adherence to prescribed treatment plan (meds, diet, exercise, smoking cessation, etc.)
what is hypertensive crisis
- severe & abrupt elevation in BP
- DBP > 120
who does hypertensive crisis often occur in
- pts with a hx of HTN who have failed to adhere to meds, or have been undermedicated
- drug users on cocaine or meth
what are S&S of hypertensive crisis (9)
- headache
- NV
- seizures
- confusion
- stupor, coma
- blurred vision
- chest pain
- dyspnea
- high BP
- signs of organ damage)
how is hypertensive crisis classified
- degree of organ involvement and rapidity in which the BP must be lowered
what do hypertensive emergencies necessitate (3)
- hospitalization
- parental admin of antiHTN drugs
- intensive care monitoring
what is the initial treatment of hypertensive emergency
- decrease MAP by 10-20% in first 1-2 hours with further gradual reduction over 24 hr
- drop in BP too far/fast could = decreased cerebral perfusion*
what IV drugs are used for hypoternsive crisis (3)
- vasodilators
- adrenergic inhibitors
- ACE-I
what is the most effective parental drug for treatment of hypertensive crisis
- IV sodium nitroprusside (nipride, nitrate)
what should you monitor during treatment of hypertensive crisis (6)
- BP and pulse every 2-3 min during initial admin
- continual ECG monitoring
- hourly urinary output
- neuro checks
- assess cardiac, renal, pulmonary systems for decompensation r/t elevated BP
- pt may be restricted to bed
what is the onset of nipride
- seconds to minutes
the rate of drug admin is determined how for hypertensive crisis
- titrated according to lvl of BP
what should you monitor during HTN crisis (4)
- BP
- cardiac monitoring
- dysrhythmias
- UO –> could be low d/t nitroprusside
