Circulation & Perfusion Flashcards
What 3 types of vessels makes up the vascular system?
Arteries, veins, and capillaries
All vessels are lined with what?
Smooth endothelial layer
What % of oxygen is bound to hemoglobin?
97%
T/F. The coronary arteries are the only arteries that fill during diastole ?
True
The ANS regulates cardiovascular function through its influence on what 2 things?
The heart and vascular system
What are baroreceptors?
Located in the walls of the heart and blood vessels. They sense blood pressure changes. If BP is low they will send signals to brain to stimulate SNS and increase HR and induce vasoconstriction.
What kind of receptors does the vascular system have to sense changes in blood pH, oxygen, and CO2?
Chemoreceptors
What is MAP?
Mean arterial pressure calculation that checks whether there’s enough blood flow, resistance, and pressure to supply blood to the major organs.
Most people need a MAP of how many mmHg to ensure enough blood flow to vital organs?
At least 60mmHg or greater
What is considered a high MAP meaning that there is a lot of pressure in the arteries?
Anything over 100mmHg
Why is a MAP under 60mmHg bad?
Because blood may not be reaching organs
What is pre load ?
Think volume
Pressure of blood entering the heart. Amount of blood in the ventricles at the end of diastole.
What is after load ?
Think resistance
Pressure of blood leaving the heart. So increase vascular resistance will increase after load.
What is stroke volume?
Amount of blood ejected with each ventricular contraction
What 3 factors affect stroke volume?
Contractility, pre load, and after load.
How is cardiac output calculated?
HR x SV
What is a normal cardiac output ?
4-7 L/min
What is the appropriate diagnosis when the heart is unable to pump adequate amounts of blood to meet metabolic demands of the body?
Decreased cardiac output
When does cardiac output increase?
With exercise or activity
When does cardiac output decrease?
Times of rest
What is a normal EF?
More than 55%
What is EF?
Amount of blood that is pumped out of the left ventricle with each contraction
Why do HF patients have a EF less than 40%?
Msl of left ventricle is not pumping as well
What 6 factors influence cardiac function?
Developmental stage, environment, lifestyle, substance abuse, medications, and patho physiological conditions.
Why does cardiac efficiency gradually decline in older adults?
Thicker and more rigid valves, decreased myocardial strength, lower exercise tolerance, more prone to orthostatic hypotension.
At what intervals do we take orthostatic vital signs?
1-3 minutes after each change of position
What neurotransmitter is released from the SNS with stress?
Catecholamines
How does heat influence cardiac output?
Causes vasodilation which increases cardiac output and oxygenation. Also increases metabolism.
How does cold influence cardiac output?
Causes vasoconstriction, slows HR, prolonged exposure can cause frostbite, loss of hypothalamic temp regulation and death
Tobacco does what to blood vessels?
Causes vasoconstriction creating a problem with afterload.
What are the 2 most common CV depressants?
Beta-adrenergic blocking agents and calcium channel blocking agents
How are CV depressants used therapeutically?
To slow HR or reduce the force of myocardial contraction
What negative effects can CV depressants have?
Reduce cardiac output and impair tissue oxygenation
What causes L sided HF?
When L ventricle does not pump sufficient amounts of blood to body organs and tissues. Fluid can back up into lungs and cause respiratory issues.
What causes R sided heart failure?
When R ventricle does not pump sufficient amount of blood to the lungs and it backs up into the venous system
What CV disease is considered the silent disease?
HTN
How do dysrhythmias influence cardiac function?
Can lower cardiac output, decrease tissue oxygenation, and increase the risk for stroke.
Which valves are most commonly affected by heart valve abnormalities?
Mitral and aortic valves
What are 2 occurrences where oxygen transport is impaired?
Anemia and carbon monoxide poisoning
What is capnography?
Non invasive and provides breath to breath ventilation. Measures CO2 in inhaled and exhaled air.
What are 3 test to measure blood oxygenation?
Pulse ox, capnography, and ABGs
What labs should be routinely checked for CV risk assessment?
Cholesterol, lipid panel, CRP, and glucose
What is a thrombus?
Stationary clot adhering to the wall of a vessel
What is an embolus?
Clot that travels into the bloodstream
What is the intra cellular space?
Inside the cells
What makes up the ECF?
Interstitial fluid, intravascular fluid, transcellular fluid.
What is the interstitial fluid?
Space between the cells. Fluid in this space is called edema.
What is the intravascular fluid?
Plasma within the blood
What is the transcellular fluid?
Special fluids like CSF, synovial, digestive juices, pleural, and peritoneal fluid.
It is recommended for women to drink how much fluid?
2,700 mL/day
It is recommended for men to drink how much fluid?
3,500mL/day
Which hormones are involved in fluid and electrolyte balance?
ADH, RAAS, thyroid, ANP, BNP, and CNP
K is important for what function?
Muscle contraction and cardiac conduction
What causes hypomagnesemia in people who have high alcohol intake?
Alcohol withdrawal can cause electrolyte shifts as glucose enters the cell
What are signs of fluid overload?
Elevated BP, bounding pulse, increased and or shallow respirations, JVD, pale, cool skin, edema, lung crackles, and ascites
T/F . It is better to prevent imbalances than to treat them?
T
What is osmolality (or tonicity) ?
The concentration of solutes creating pressure in body fluid
What is the MAP equation?
SBP + (2x DBP) / 3
To promote peripheral arterial circulation what should we teach the client and family?
Tobacco cessation, foot care, regular exercise, proper positioning, medication, and warmth.
What can a BNP lab value tell us?
Released by the atria in response to stretch. Indicates hypervolemia.
Helps determine presence of heart failure with fluid excess and to distinguish from pulmonary edema
ANP, BNP, and CNP are hormones produced where?
By heart cells
How does thyroid hormone influence cardiac output?
Increase in thyroid hormone causes an increase in cardiac output
What are common sites for nitro ointment?
Chest or deltoid
How long can a nitro patch be worn for?
12-24 hours per day
What does it mean to give the patient a “nitro holiday”?
Making sure to give them a break with usage so that tolerance does not build up
Why do we rotate application sites of nitro patch?
To avoid skin irritation
T/F. Always remove a nitro patch prior to defibrillation or cardioversion to prevent burns.
True
Is nitro a vasodilator or constrictor?
Vasodilator
What are the two purposes of nitro?
To alleviate angina and in some cases reduce blood pressure
Do high doses of nitro affect pre load or after load?
After load
