exam 3 239
Terms in this set (88)
lungs are a very low what?
pressure system (12mm/Hg)
how is the pressure in lungs measured?
in millimeters per mercury
what are atria?
example of collection chambers
main pumping chambers of the heart
valves prevent what?
backflow (one set is open while the other is closed)
left side failure of the valve is called what?
fibrous covering sack around the heart
muscle wall does the contracting
if you have an infection int he endocardium what is it called?
the heart muscle generates its own what?
stroke volume x heart rate
what is cardiac reserve?
maximum percentage of increased cardiac output that can be achieved above the normal resting level
increasing HR will increase what?
CO if the SV stays constant or increases
increased HR causes what?
decreased ventricular filling
very rapid tachycardias will cause what?
decreased CO also decreased SV
what are stroke volume and cardiac output determined by?
preload, after load, and contractility
what does chronotropic effect modify?
what is cardiac output
amount of blood the heart pumps each minute or the volume of blood ejected by ventricle into the circulation per minute
How does the PNS cause lowing of the HR?
by increasing vagus nerve activity
volume of blood that stretched ventricles. end of diastole. occurs just before systole
what is preload determined by?
venous blood return
end diastolic volume + the amount of venous blood returning to the heart during diastole
end diastolic volume =
venous return to the heart (determines preload)
pressure ventricles must exert to eject blood
main controllers of systemic vascular resistance (SVR) by vasoconstricting and vasodilating
small arteries and arterioles pass through
which types of vessels are more compliant? arteries or veins?
what is the important feature of microcirculation that occurs?
ability of the organs and tissues to regulate their blood flow based on metabolic needs (nutritional needs of the tissues)
why is local control particularly important for skeletal muscles?
skeletal muscle demands change frequently
what are the two mechanisms that control autoregulation?
metabolic and myogenic autoregulation
example of endothelial control of blood flow
nitroglycerin causes a release of nitric oxide - smooth muscle relaxation of vessels
long term blood pressure regulation is controlled by what?
2 physiological processes - renal monitoring and adjusting the extracellular fluid
what is the control of BP very dependent on?
on the kidneys and their regulation of extracellular fluid volume
what nerve are the parasympathetic impulses to the heart transmitted through?
sympathetic side - vagal nerve
increase in blood pressure and heart rate
parasympathetic side - vagal nerve
decrease in blood pressure and heart rate
what is the most common secondary HTN cause?
renal hypertension (reduced renal blood flow due to the activation of the RAA mechanism)
diagnostic criteria for HTN?
what is HTN a major risk factor for?
treatment goals for HTN (measurable goal) BP
decrease BP < 140/90 mm HG
what are treatments for HTN?
modifying risk factors (lifestyle modifications) going to gym, losing weight, decreasing salt in diet
what is the 1st adverse effect of ACE inhibitors?
dry persistent cough (10-20%)
what is the 2nd adverse effect of ACE inhibitors?
hyperkalmeia in patients with DM or renal disease, potassium supp, spironolactone 2.
what is one nursing implication of ACE inhibitors?
first line drug used to treat HTN in patients with DM and renal impairment
what is a second NI of ACE inhibitors?
often used in combination with diuretics (thiazide usually)
what is one NI of ARB (angiotensin II receptor blocker)
may not be effective in controlling HTN in some people. usually prescribed along with a low dose diuretic
What is an NI for beta blockers?
take apical pulse and BP before administering
___________ treatment with two classes of diuretic increases the diuretic effect?
what happens when preload is decreased?
decreasing vascular volume by increasing sodium and water excretion
what is an action of hydrochlorothiazide?
increase renal excretion of sodium and water
what is the onset of action for Furosemide (lasix) IV administration?
onset 5 minutes, peaks in 30 minutes, lasts 2 hours
what is the onset of action for furosemide (lasix) oral form?
30-60 minute onset
what are two NI you should be concerned with while taking furosemide (lasix)
daily weights and that high sodium diet decreases diuretic effect
what is one NI to be concerned with if taking spironolactone (aldactone)
it is usually combined with thiazide or loop to prevent potassium excess/loss (imbalance)
what is another NI to be concerned with if taking spironolactone (aldactone)
patients should avoid excess potassium in diet or taking potassium supplements (avoid bananas)
what is one teaching point for antihypertensives?
Know signs and symptoms of orthostatic hypotension (elderly pt are most at risk for falling due to orthostatic hypotension)
what is another teaching point for antihypertensives?
First-dose phenomenon- risk for falls related to antihypertensive medications
what is secondary hypocholesteremia caused by?
high caloric intake
what is dyslipidemia associated with?
blood test for triglycerides requires what?
12 hour fasting
what is the most important complication of atherosclerosis?
most effective drug in reducing the major types of dyslipidemia?
what are statins metabolized by?
cytochrome p450 enzyme. has many food/drug interactions (no grapefruit juice)
what is an adverse effect of statins?
myopathies (muscle pain or injury)
what is one teaching point for statins?
notify provider if muscle pain or weakness
what is the action of fibrates?
increase oxidation of fatty acids in the liver
what is the goal treatment for LDL cholesterol?
< 100 mg/dL
what is left-sided heart failure caused by?
acute myocardial infarction (muscle)
clinical manifestations of HF?
sudden weight gain and pitting edema in feet and akles
respiratory manifestations due to congestion from left-sided failure
crackles in lung bases and an audible s3
second line medication used for treatment of heart failure
cardiac glycosides (digitalis)
what is the positive inotropic effect of cardiac glycosides?
what is the negative chronotropic effect of cardiac glycosides?
slows heart rate
in a patient diagnosed with HF what does digoxin slow/increase?
digoxin slows the HR and increases contractility = increased efficiency of heart
digoxin causes increased BUN and creatinine which causes what?
renal problems - watch for hyperkalemia and reduce digoxin dose to avoid toxicity
digoxin + furosemide =
increased risk of digoxin toxicity
what is the onset of digoxin parenterally
10-30 minutes, peaks in 1-5 hours
what is the onset of digoxin orally?
30-120 minutes, peaks in 6 hours
what are early toxicity S/S of digoxin
anorexia, nausea, and vomiting
what are later toxicity S/S of digoxin
vision changes (halos, blurry, yellow-tint, fatigue, CV arrhythmias - can vary from bradycardia to ventricular fibrillation
what is a NI for digoxin
monitor potassium normal range = 3.5-5.0 mEg/L
what is hypovolemic shock:
loss of blood, loss of plasma, loss of extracellular fluid
example of distributive shock:
anaphylactic shock (type 1 hypersensitivity reaction)
clinical manifestations of shock:
oliguria (decreased urine output)
why is oliguria an important sign
one of the best indicators of blood to vital organs is urine output
in shock it is important to assess what?
vital signs and urinary output
antidote for digoxin toxicity?
Digoxin immune Fab (Digibind)