Perfusion Notes Flashcards
What are antiplatelets?
Keep the platelets from clumping together & forming a clot. Disrupts the blood flow & can cause a problem with the heart leading to a MI.
What is a thrombolytic?
A drug used to bust open a blood clot.
What are cardiac glycosides?
Drugs used for the heart to strengthen the contraction of the heart (Digoxin, Lanoxin).
What is telemetry?
A pt. with a heart monitor & monitoring that pt’s heart.
What is perfusion?
Flow of the blood through arteries & capillaries delivering nutrients and oxygen to cells. If interrupted for long period of time you could die!
* Veins carry the blood to the heart & arteries carry the blood away from the heart.
What things go with perfusion?
Cap refill, pulses, heart sounds, & etc.
Where are CBC labs drawn from? Where are ABGs drawn?
The veins. ABGs are drawn from the artery.
What happens with variations from baby to death with perfusion?
*When baby is birthed (cord cut off) -doesn’t have the same circulatory system. Things shut off (ductus arteriosus) and seal off so we can experience the same as the parents outside of the body.
*As we age things happens physiological & psychological.
*Arteries and veins lose their elasticity- (physiological example). B/P goes up in elderly & can’t do what it needs to.
Changes in perfusion can be temporary or permanent. Name some different types of conditions with altered perfusion.
*MI (coronary artery blocked off & causes permanent damage-Will need to put a stent in coronary artery to get blood flow going again in Cath lab
*Stroke (something blocked off going to head)
*Heart-Coronary arteries
*Shock (body decompensated)
*When a MI is not treated & you become very sick, muscle is stunned & not getting enough o2 can lead to CHF
Chronic disorders that affect perfusion?
*Silent killer-HTN
*Heart failure (heart muscle affected & not pumping properly leading to fluid overload. (test question)
*Sickle cell anemia (affects blood-Hemoglobin & Hematocrit (carry O2) labs need to be looked at.
*Hemophilia-free bleeders-active bleeding & don’t have proper clotting mechanisms
What is central perfusion?
*Central perfusion is generated by cardiac output—the amount of blood pumped by the heart each minute. Heart beat/stroke volume are affected. Two systems to function-Electrical System(EKG STRIP-Atrial Fibrillation)/mechanical-Closing/opening of valves-Ventricle, Atrial, & valves(leaflets of valves cause back flow in heart), Aortic stenosis-closing of lumen.
*Pulse is an indicator of perfusion. *Pacemakers help with rate & stimulation of the heart.
What is Cardiac Output?
-Cardiac Output-Heart beat in a minute
-Beats/minute x volume/beat)=volume/minute
-Stroke volume=volume/beat (Amount of blood ejected from each ventricle during contraction. It’s affected by the preload, contractility, & afterload.)
-Cardiac output=HR X SV; normal is 4-6L/min
-Volume of blood pumped by ventricle/minute
*Each heart beat pumps about 60 mL of blood in a minute(5 L/minute).
What are the two systems cardiac output requires to function?
Two systems to function-Electrical System: P wave, QRS Complex, (EKG STRIP-Atrial Fibrillation-Something is not firing right from SA node to AV node to Bundle of His to Purkinje fibers)
*Mechanical (Structures)-Closing/opening of valves-Ventricle, Atrial, & valves stay open (leaflets of valves cause back flow in heart), Mitral valve stenosis/Aortic stenosis-closing of lumen(narrowing).
*Any problem with any system will affect the cardiac output.
Firing of the heart
*SA Node(pacemaker of heart) helps with producing normal heart beat Impulse is originated from.
*AV Node-Heartbeat goes down if SA Node is not functioning properly (40-60 beats/minute)
*When AV Node is not working properly the Bundle of His takes over (20-40)-Bifurcates in two directions to Purkinje Fibers-Nothing to around 20 heart beat (takes over when Bundle of His is not working properly.
What happens when SA Node fires on a EKG strip?
*EKG-P wave when SA Node fires (right atrium) QRST (Heartbeat traveling through ventricles)
What is going on with ventricular fibrillation and ventricular tachycardia?
*Ventricles pumping really fast causing decreased Cardiac Output. Deadly situation.
*No blood is being pumped and if not shocked they will die if it’s not in a normal rhythm. Pt. needs to be shocked with ADE. Atrial fibrillation problems alter the perfusion and cardiac output.
*ADE-Shocks deadly rhythms in pt. into normal sinus rhythm.
What happens with the mechanical structures of the cardiac output?
Mechanical Structures-Heart has a septum that separates the left from right side. There is a right & left atrium/ventricle. The right atrium gets deoxygenated blood from superior/inferior vena cava. (Vena Cava largest vein) When SA node fires (right atrium contracts) opening tricuspid value-blood goes to right ventricle. Pulmonic valve opens goes to pulmonary artery feeding both lungs. Oxygenated blood and co2 goes off & goes to veins to heart and dumps in left atrium. Mitral valve /bicuspid valve(2 leaflets) opens and down to left ventricle to aortic valve to aorta. Blood goes to coronary artery openings and oxygen goes and perfuses brain & rest of body (renal arteries). Femoral artery & veins get blood & to rest of body. Cycle starts over . You can’t make it if aorta ruptures.
*Aortic dissection-death.
Why does the blood pressure depend on the cardiac output of the heart?
Pressure from heart through ventricles creates the blood pressure. *Good indicator of cardiovascular system function.
*High blood pressure-pt. is perfusing to much (risk of a stroke). To low of a blood pressure-pt. is perfusing little.
-More blood more volume (higher pressure). Less blood less volume (hemorrhaging).
What is the viscosity of blood?
-Thickness of blood (if it’s thicker the more time it takes to pump effectively.)
-Hematocrit (percentage of viscosity) *If hematocrit goes up-blood flow slows down(thicker) & heart works harder to pump the blood.
*If blood is thin (Like a cut) -The pt. will bleed excessively.
-Importance of patient teaching when people are on anticoagulants.
*People on blood thinners you want thin blood to prevent clots.
What is peripheral vascular resistance?
-The resistance of blood flow & is determined by size of blood vessel. *When vessels lose elasticity, the vessel doesn’t contract as it should. Blood pressure gets higher & higher. *As we get older the vessels lose elasticity.
What is the systolic blood pressure?
Pressure exerted when blood is ejected into arteries. Normal systolic blood pressure is 120 mmHg or below.
What is the diastolic blood pressure?
Pressure blood exerts within the arteries between heartbeats. Normal diastolic blood pressure 80 mmHg or below.
What is preload?
*Cardiac drugs are prescribed based on preload or afterload of heart.
-Volume of blood received by the heart.
*Preload is stretch. The amount of volume being returned to the heart (What’s coming into the heart).
*Volume of blood in the ventricles after the end of diastole (end diastolic pressure)
-Increased in Hypervolemia, Regurgitation of cardiac valves, and heart failure
What is afterload?
-Pressure or resistance the heart has to overcome to eject blood.
*Afterload is the squeeze. The amount of resistance that the heart has to overcome in order to eject blood. (Resistance the left ventricle has to overcome to circulate the blood)
-Increased in hypertension and vasoconstriction (things clamping down)
*Increase in afterload =Increase in cardiac workload