NR 341
(EDAPT WEEK 3 NOTES)
PERFUSION ALTERATIONS
Complex Adult Health
,WEEK 3 EDAPT NOTES NR 341
PERFUSION ALTERATIONS
Perfusion is described as the passage of oxygenated capillary blood through body
tissues. Central perfusion refers to blood flow to major body organs. Peripheral perfusion is
blood flow to the extremities.
Altered perfusion is the inability to adequately oxygenate organs and tissues and can range
from minimal to severe. Normal perfusion is dependent on cardiac output and correct
blood flow distribution. Vascular patency and tone are essential.
Tissue ischemia results from decreased perfusion. Infarction is the result of tissue death
due to severe decreased perfusion.
Altered peripheral perfusion can result in skin ulcers and cell death, such as
gangrene.
Altered central perfusion can result in life-threatening events, such as acute
myocardial infarction, heart failure, stroke, and shock.
The tricuspid valve is between the right atrium and the right ventricle. A stenotic or incompetent valve
can lead to impaired blood flow.
The bicuspid valve (mitral valve) is between the left atrium and the left ventricle.
The pulmonic valve is between the right ventricle and the pulmonary artery.
The aortic valve is between the vena cava and the left ventricle.
In which part of the vascular system does disruption initiate the coagulation
cascade, forming a blood clot?
Arterioles are lined with endothelium that maintains homeostasis, promotes blood flow,
and inhibits coagulation. When the endothelial surface is disrupted, the coagulation
cascade is initiated, and a clot forms.
Arterioles contain smooth muscle with little elasticity. They respond to low oxygen and
increased carbon dioxide by dilating and constricting.
Capillaries connect the arterioles to the venules. Cellular nutrients are exchanged in these
thin-walled vessels.
Veins return blood to the right atrium. The venous system is a low-pressure, high-volume
system. The amount of blood in this system is affected by arterial flow, venous
compression, and right arterial pressure.
,During a cardiovascular assessment, which health history finding is most significant?
Recreational drugs, especially stimulants such as cocaine and methamphetamine, are
a significant cause of dysrhythmias. Intravenous (IV) injection of abused drugs is a risk
factor for inflammatory and infectious conditions of the heart (e.g., endocarditis).
Calcium is involved in the contraction of muscles but is not considered a significant factor
in heart disease.
Metastatic breast cancer is not a significant contributor to heart disease.
Streptococcal (bacterial), not viral pharyngitis, is a risk factor for inflammatory heart
disease (rheumatic endocarditis).
A client presents to the emergency department with chest pain and shortness of
breath. Which subjective data related to the cardiovascular system should be
obtained from the client?
Past health history, including smoking and alcohol use, and acute and chronic illness
may affect the cardiovascular system.
Symptoms such as dizziness with position changes, fatigue, syncope, and heart palpitations
must be explored.
Cardiovascular problems can disrupt sleep. It is important to assess the number of pillows
needed to sleep or the need to sleep upright in a chair.
Though important to the cardiovascular assessment, neck vein distention and the presence
of dependent edema are objective data.
A nurse is discussing the dangers of a sedentary lifestyle with a client who has risk
factors for coronary artery disease (CAD). Increasing physical activity will directly
contribute to reducing which risk factor?
Increased exercise without an increase in caloric intake will result in weight loss,
while reducing the risk associated with obesity. Exercise increases lipid metabolism
and increases high-density lipoprotein (HDL), thus reducing coronary artery disease
(CAD).
Exercise may indirectly reduce the risk of CAD by controlling hypertension, promoting
glucose metabolism, and reducing both physical and emotional stress.
Bradycardia and hypotension are not major symptoms of CAD.
, Factors affecting cardiac output:
Cardiac output can be difficult to help clients understand. Using commonly understood
terms, such as a 2-liter bottle of soda, can promote understanding that leads to compliance
with treatment.
Cardiac Output
Cardiac output (CO) is the amount of blood pumped by each ventricle in 1 minute. It is
calculated by multiplying the stroke volume (SV) times the heart rate (HR). CO = SV x HR
The normal adult at rest has a CO in the range of 4–8 L/min.
Factors Affecting Heart Rate
Many factors can affect heart rate or stroke volume, therefore impacting CO.
Rapid heart rate reduces diastolic filling and perfusion of the coronary arteries.
Stroke volume is affected by preload, contractility, and afterload.
Cardiac Reserve
Health (exercise) and illness (hypovolemia, stress) affect the cardiovascular system. The
ability to respond to demands by altering CO is called cardiac reserve.
PRELOAD, CONTRACTILITY, and AFTERLOAD:
The volume of blood stretching the ventricles at the end of diastole is called preload.
Increased by aortic valve disease, hypervolemia, and heart failure
Decreased by rapid heart rate and hypovolemia
Afterload is the peripheral resistance which the left ventricle must pump against.
Affected by the size of the ventricle, wall tension, and elevated arterial blood
pressure
Over time, increased resistance to eject blood results in ventricular hypertrophy.
Increased by hypertension (vasoconstriction)
Contractility is increased by epinephrine and norepinephrine released by the sympathetic
nervous system.
Increased contractility increases the stroke volume by increasing ventricular
emptying
(EDAPT WEEK 3 NOTES)
PERFUSION ALTERATIONS
Complex Adult Health
,WEEK 3 EDAPT NOTES NR 341
PERFUSION ALTERATIONS
Perfusion is described as the passage of oxygenated capillary blood through body
tissues. Central perfusion refers to blood flow to major body organs. Peripheral perfusion is
blood flow to the extremities.
Altered perfusion is the inability to adequately oxygenate organs and tissues and can range
from minimal to severe. Normal perfusion is dependent on cardiac output and correct
blood flow distribution. Vascular patency and tone are essential.
Tissue ischemia results from decreased perfusion. Infarction is the result of tissue death
due to severe decreased perfusion.
Altered peripheral perfusion can result in skin ulcers and cell death, such as
gangrene.
Altered central perfusion can result in life-threatening events, such as acute
myocardial infarction, heart failure, stroke, and shock.
The tricuspid valve is between the right atrium and the right ventricle. A stenotic or incompetent valve
can lead to impaired blood flow.
The bicuspid valve (mitral valve) is between the left atrium and the left ventricle.
The pulmonic valve is between the right ventricle and the pulmonary artery.
The aortic valve is between the vena cava and the left ventricle.
In which part of the vascular system does disruption initiate the coagulation
cascade, forming a blood clot?
Arterioles are lined with endothelium that maintains homeostasis, promotes blood flow,
and inhibits coagulation. When the endothelial surface is disrupted, the coagulation
cascade is initiated, and a clot forms.
Arterioles contain smooth muscle with little elasticity. They respond to low oxygen and
increased carbon dioxide by dilating and constricting.
Capillaries connect the arterioles to the venules. Cellular nutrients are exchanged in these
thin-walled vessels.
Veins return blood to the right atrium. The venous system is a low-pressure, high-volume
system. The amount of blood in this system is affected by arterial flow, venous
compression, and right arterial pressure.
,During a cardiovascular assessment, which health history finding is most significant?
Recreational drugs, especially stimulants such as cocaine and methamphetamine, are
a significant cause of dysrhythmias. Intravenous (IV) injection of abused drugs is a risk
factor for inflammatory and infectious conditions of the heart (e.g., endocarditis).
Calcium is involved in the contraction of muscles but is not considered a significant factor
in heart disease.
Metastatic breast cancer is not a significant contributor to heart disease.
Streptococcal (bacterial), not viral pharyngitis, is a risk factor for inflammatory heart
disease (rheumatic endocarditis).
A client presents to the emergency department with chest pain and shortness of
breath. Which subjective data related to the cardiovascular system should be
obtained from the client?
Past health history, including smoking and alcohol use, and acute and chronic illness
may affect the cardiovascular system.
Symptoms such as dizziness with position changes, fatigue, syncope, and heart palpitations
must be explored.
Cardiovascular problems can disrupt sleep. It is important to assess the number of pillows
needed to sleep or the need to sleep upright in a chair.
Though important to the cardiovascular assessment, neck vein distention and the presence
of dependent edema are objective data.
A nurse is discussing the dangers of a sedentary lifestyle with a client who has risk
factors for coronary artery disease (CAD). Increasing physical activity will directly
contribute to reducing which risk factor?
Increased exercise without an increase in caloric intake will result in weight loss,
while reducing the risk associated with obesity. Exercise increases lipid metabolism
and increases high-density lipoprotein (HDL), thus reducing coronary artery disease
(CAD).
Exercise may indirectly reduce the risk of CAD by controlling hypertension, promoting
glucose metabolism, and reducing both physical and emotional stress.
Bradycardia and hypotension are not major symptoms of CAD.
, Factors affecting cardiac output:
Cardiac output can be difficult to help clients understand. Using commonly understood
terms, such as a 2-liter bottle of soda, can promote understanding that leads to compliance
with treatment.
Cardiac Output
Cardiac output (CO) is the amount of blood pumped by each ventricle in 1 minute. It is
calculated by multiplying the stroke volume (SV) times the heart rate (HR). CO = SV x HR
The normal adult at rest has a CO in the range of 4–8 L/min.
Factors Affecting Heart Rate
Many factors can affect heart rate or stroke volume, therefore impacting CO.
Rapid heart rate reduces diastolic filling and perfusion of the coronary arteries.
Stroke volume is affected by preload, contractility, and afterload.
Cardiac Reserve
Health (exercise) and illness (hypovolemia, stress) affect the cardiovascular system. The
ability to respond to demands by altering CO is called cardiac reserve.
PRELOAD, CONTRACTILITY, and AFTERLOAD:
The volume of blood stretching the ventricles at the end of diastole is called preload.
Increased by aortic valve disease, hypervolemia, and heart failure
Decreased by rapid heart rate and hypovolemia
Afterload is the peripheral resistance which the left ventricle must pump against.
Affected by the size of the ventricle, wall tension, and elevated arterial blood
pressure
Over time, increased resistance to eject blood results in ventricular hypertrophy.
Increased by hypertension (vasoconstriction)
Contractility is increased by epinephrine and norepinephrine released by the sympathetic
nervous system.
Increased contractility increases the stroke volume by increasing ventricular
emptying
