Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Cardiotonic drugs
pharm exam 3: drugs affecting cardiac circulation in heart failure
| Questi | Answer |
|---|---|
| define automacity | ability to spontaneously initiate an electrical impulse without external stimuli (self-excitement) |
| 3 properties of the heart | automaticity; conductivity; refractoriness |
| define conductivity | ability to transmit action potential from cell to cell |
| where does conductivity exists | in heart muscles and electrical conductions system |
| define refractoriness | people during cardiac cycle during which a stimulus fails to produce an action potential |
| normal cardiac output volume | 4-8 L/minute |
| What part of the heart does the sympathetic nervous system innervate? | all of the heart |
| What part of the heart does the parasympathetic nervous system innervate? | AV node, atria, little in the ventricle |
| hormones that affect cardiac output | epinephrine, norephinephrine, acetylcholine |
| normal stroke volume | 70 mL/beat |
| 3 factors affecting stroke volume | preload, contractility, afterload |
| define preload | ventricular filling |
| define contractility | ventricular contraction |
| define afterload | systemic vascular resistance |
| define Starling's Law | degree of stretch = stretching the myocardial fibers during diastole will increase the force of contraction during systole |
| Starling's Law describes the increase in... | preload |
| inotropic drugs affect what factor in stroke volume? | contractility |
| effects of + inotropic drugs | strengthens contractility |
| effects of - inotropic drugs | decreases contractility |
| chronotropic drugs affect what part of cardiac output? | heart rate |
| effects of + chronotropic drugs | increases heart rate by increased impulses from SA node |
| effects of - chronotropic drugs | decreases heart rate by decreased impulses from SA node |
| dromotropic drugs influence what? | conduction |
| effects of + dromotropic drugs | speeds conduction |
| effects of - dromotropic drugs | slows conduction |
| 5 forms of heart problems | heart failure; hypertension, arrhythmia, angina, myocardial infarction |
| define heart failure | heart is no longer pumping enough blood for metabolic demands of the body |
| define hypertension | elevated BP |
| What causes elevated BP in hypertension | blood volume is greater compared to space available inside blood vessels |
| define arrhythmias | electrical conduction problems that occur when pathways malfunction |
| define angina | chest pain; way of signaling that some of heart cells are not getting enough oxygen |
| define myocardial infarction | damage to heart muscle due to ischemia (lack of oxygen) |
| another name for cardiotonics | cardiac glycosides |
| prototype for cardiotonic (cardiac glycosides) | digoxin (lanoxin) |
| other names for digitalis | foxglove; cardiotonics; cardiac glycosides |
| What was digitalis (foxglove) initially prescribed for? | dropsy (edema) |
| primary action of digitalis (foxglove) | on the heart; duresis occurs following improved circulation |
| dynamics of digoxin (Lanoxin) | more influx of calcium into cells |
| How does digoxin increase force of contraction? | more complete systolic emptying; heart size decreases; increased kidney perfusion |
| What happens when force of heart contraction is increased? | CO increases; systolic emptying is more complete; heart size decreases |
| What causes duresis with digoxin? | increased kidney perfusion |
| What property of digoxin allows for increased force of contraction? | + ionotropic = increased cardiac output |
| How does digoxin increase vagal activity? | conduction through AV node is decreased and refractory time is prolonged |
| What properties of digoxin allow for increased vagal activity? | - dromotropic; - chrontopic |
| EKG signal seen with use of digoxin symbolizing increased vagal activity | prolonged p-r interval |
| uses for digoxin | congestive heart failure; atrial dysrhythmias |
| Kinetics of digoxin | po - absorption 2 hours IV - 10 minutes |
| Why can digoxin lead to accumulation | widely distributed; bound to albumin in blood |
| clinical manifestations of heart failure | weak, rapid heart rate; less than normal cardiac output; SOB |
| Why is digoxin used in heart failure? | slows the heart and strengthens contraction |
| Where is digoxin detoxified? | in liver; only small amount destroyed and excreted daily (leading to accumulation) |
| Why is a loading dose required for digoxin? | blood protein must be saturated before blood concentration is stabilized |
| define digitalization | use of a loading dose to achieve high plasma levels of digoxin quickly |
| How long does it take to reach plateau drug levels if no loading dose of digoxin is given? | 6 days |
| Loading dose varies with... | age, body size, health problems |
| describe pediatric dose of digoxin | proportionally higher doses according to weight |
| maintenance of digoxin | may take a week to reach state |
| How does renal impairment affect digoxin levels | slows elimination |
| percentage of patients who have digoxin toxicity | 10-25% of patients |
| describe optimal dose of digoxin | close to toxic dose |
| first symptoms of digoxin toxicity appears where? | vision, GI, cardiac |
| vision symptoms of digoxin toxicity | blurred, double vision, yellow or green color changes, halos around objects |
| GI symptoms of digoxin toxicity | anorexia, nausea, vomiting, diarrhea |
| apical impulse rates in adult digoxin toxicity | 60 or less |
| apical impulse rates in infants digoxin toxicity | 100 or less |
| How long should you measure the apical impulse when digoxin toxicity is suspected? | 1 minute |
| EKG changes seen in digoxin toxicity | prolonged p-r interval, shortening QT, T wave inversion, PVCs |
| predispositions for digoxin toxicity | hypokalemia, hypocalcemia, vomiting, gastric suctioning, diuretics |
| IV predisposition for digoxin toxicity | large amount of IV dextrose |
| Why does a large amount of IV dextrose a predisposition for digoxin toxicity? | causes intracellular shift of potassium |
| age predispositions for digoxin toxicity | young and old |
| health alterations that predispose for digoxin toxicity | liver and kidney dysfunction |
| normal potassium level | 3.5-5 |
| normal calcium level | 8.5-10 |
| nursing assessment diagnositc of digoxin toxicity | appearance (color/edema); tachycardia/bradycardia, dysrhythmia,m pulmonary rales, anorexia, visual distrubances |
| What to monitor with digoxin toxicity | I&O; weight; apical pulse for one full minute |
| Labs to draw with digoxin toxicity | potassium, calcium, kinetics |
| When do you hold digoxin | adult apical impulse below 60; infant apical impulse below 90-110 |
| When do you check calculation on digoxin? | prior to administration |
| Antidote for digoxin | digoxin immune FAB (Digibind) |
| What color is the bottle of digoxin for children? | green |
| Teaching for digoxin use | how/when to call doctor; how to measure digoxin with children; daily weight may need increase in potassium rich foods/supplementation |
| How much weight gain may indicate fluid retention? | 1-2 pounds |
| 1 kg = ?? lbs | 2.2 |
| Human B-type natiuretic peptide prototype | nesiritide (natrecor) |
| therapeutic use of nesiritide (natrecor) | acute heart failure |
| what does nesiritide (natrecor) do? | recombinate DNA - identical to peptide secreted by ventricle with fluid and pressure overload |
| Action of nesiritide (natrecor) | decreases preload/afterload; increases diuresis and secretion of sodium; decrease renin-angiotension-aldosterone and secretion of norephenephrie |
| nesiritide (natrecor) onset | immediate |
| Nursing considerations for nesiritide (natrecor) | give IV, bolus then separate IV; monitor urinary output |
| Why is nesiritide (natrecor) given in separate IV? | not compatible with many drugs |
| What to do in emergency situation while on neiritide (natrecor) | put patient on heart monitor |
Created by:
1818554924
Popular Nursing sets