copyright © 2008 lippincott williams & wilkins. 1 assessment of cardiovascular function...
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Copyright © 2008 Lippincott Williams & Wilkins.
Assessment of Cardiovascular Function
Assessment of Cardiovascular Function
Hemodynamic Monitoring
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Copyright © 2008 Lippincott Williams & Wilkins.
Overview of Anatomy and Physiology of the Heart
Overview of Anatomy and Physiology of the Heart
Three layers of the heart: Endocardium (inner lining) Myocardium (muscle fibers) Epicardium (exterior layer)
Heart is encased in the pericardium
Four chambers 2 atria, 2 ventricles
Heart valves 2 atrioventricular valves, 2 semilunar valves
Coronary arteries Cardiac conduction system
Three layers of the heart: Endocardium (inner lining) Myocardium (muscle fibers) Epicardium (exterior layer)
Heart is encased in the pericardium
Four chambers 2 atria, 2 ventricles
Heart valves 2 atrioventricular valves, 2 semilunar valves
Coronary arteries Cardiac conduction system
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Structure of the HeartStructure of the Heart
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The Cardiac CycleThe Cardiac Cycle
During systole, the heart muscle contracts and blood is ejected from the chambers
During diastole, the heart muscle relaxes and the chambers fill with blood
During systole, the heart muscle contracts and blood is ejected from the chambers
During diastole, the heart muscle relaxes and the chambers fill with blood
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The Cardiac CycleThe Cardiac Cycle
Muscle contraction is initiated by action potentials the normally originate in the sinoatrial node
Ventricular contraction causes the AV valves (tricuspid and mitral) to close, which indicates the beginning of ventricular systole. The semilunar valves (aortic and pulmonic) were closed during
the previous filling (diastole) period and remain closed during this time
Continued contraction raises pressure in the ventricles above the pressure in the aorta and pulmonary trunk, causing the semilunar valves to open Blood is ejected from the ventricles, through the semilunar valves,
into the pulmonary artery (right) and aorta (left)
Muscle contraction is initiated by action potentials the normally originate in the sinoatrial node
Ventricular contraction causes the AV valves (tricuspid and mitral) to close, which indicates the beginning of ventricular systole. The semilunar valves (aortic and pulmonic) were closed during
the previous filling (diastole) period and remain closed during this time
Continued contraction raises pressure in the ventricles above the pressure in the aorta and pulmonary trunk, causing the semilunar valves to open Blood is ejected from the ventricles, through the semilunar valves,
into the pulmonary artery (right) and aorta (left)
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The Cardiac CycleThe Cardiac Cycle
Once the ventricles relax and pressures decrease, blood flowing back (from the pulmonary artery and aorta) towards the relaxed ventricles causes the semilunar valves to close. This is the beginning of ventricular diastole The AV valves remain closed
When the ventricular pressure becomes lower than the pressure within the atria, the AV valves open and blood flows from the atria into relaxed ventricles. This represents approximately 75% of ventricular filling.
The atria then contract and complete the remainder of ventricular filling
Once the ventricles relax and pressures decrease, blood flowing back (from the pulmonary artery and aorta) towards the relaxed ventricles causes the semilunar valves to close. This is the beginning of ventricular diastole The AV valves remain closed
When the ventricular pressure becomes lower than the pressure within the atria, the AV valves open and blood flows from the atria into relaxed ventricles. This represents approximately 75% of ventricular filling.
The atria then contract and complete the remainder of ventricular filling
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Coronary ArteriesCoronary Arteries
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Cardiac Conduction SystemCardiac Conduction System
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Terms: Cardiac Action Potential Terms: Cardiac Action Potential
Depolarization: electrical activation of a cell caused by the influx of sodium into the cell while potassium exits the cell
Repolarization: return of the cell to the resting state caused by re-entry of potassium into the cell while sodium exits
Refractory periods: Effective refractory period: phase in which cells are
incapable of depolarizing
Depolarization: electrical activation of a cell caused by the influx of sodium into the cell while potassium exits the cell
Repolarization: return of the cell to the resting state caused by re-entry of potassium into the cell while sodium exits
Refractory periods: Effective refractory period: phase in which cells are
incapable of depolarizing
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Cardiac Action PotentialCardiac Action Potential
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Great Vessel and Heart Chamber Pressures
Great Vessel and Heart Chamber Pressures
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Cardiac outputCardiac output
Cardiac output refers to the amount of blood pumped by each ventricle during a given period Average human cardiac output is 5 liters per
minute (4-8 is normal) Stroke volume (SV) refers to the amount of
blood ejected per heartbeat
CARDIAC OUTPUT = SV x HR
Cardiac output refers to the amount of blood pumped by each ventricle during a given period Average human cardiac output is 5 liters per
minute (4-8 is normal) Stroke volume (SV) refers to the amount of
blood ejected per heartbeat
CARDIAC OUTPUT = SV x HR
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Terms: Cardiac OutputTerms: Cardiac Output
Stroke volume: the amount of blood ejected with each heartbeat
Cardiac output: amount of blood pumped by the ventricle in liters per minute
Preload: degree of stretch of the cardiac muscle fibers at the end of diastole
Contractility: ability of the cardiac muscle to shorten in response to an electrical impulse
Afterload: the resistance to ejection of blood from the ventricle
Ejection fraction: the percent of end-diastolic volume ejected with each heartbeat
Stroke volume: the amount of blood ejected with each heartbeat
Cardiac output: amount of blood pumped by the ventricle in liters per minute
Preload: degree of stretch of the cardiac muscle fibers at the end of diastole
Contractility: ability of the cardiac muscle to shorten in response to an electrical impulse
Afterload: the resistance to ejection of blood from the ventricle
Ejection fraction: the percent of end-diastolic volume ejected with each heartbeat
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CO = HR x SVCO = HR x SV
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Hemodynamic Monitoring-Noninvasive
Hemodynamic Monitoring-Noninvasive
Blood pressure Orthostatic vital signs
Blood pressure Orthostatic vital signs
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Hemodynamic MonitoringHemodynamic Monitoring
Blood Pressure Measurement Systemic blood pressure is exerted on the walls
of the arteries during ventricular systole and diastole
Affected by factors such as cardiac output, distension of the arteries, and the volume, velocity and viscosity of blood
Normal: 100/60-135-85
Blood Pressure Measurement Systemic blood pressure is exerted on the walls
of the arteries during ventricular systole and diastole
Affected by factors such as cardiac output, distension of the arteries, and the volume, velocity and viscosity of blood
Normal: 100/60-135-85
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Hemodynamic MonitoringHemodynamic Monitoring
Orthostatic (postural) blood pressure/HR measurements The patient should be supine and flat for 5-10 minutes, then the
initial BP and HR are measured The patient is then placed in the sitting position, with feet
dangling. Repeat measurements are taken within 1-3 minutes of position change
Repeat the procedure with the patient in the standing position Record BP and HR, as well as the patient position that
each was taken Be sure to ask about symptoms of dizziness or feeling
faint during position changes - record this as well
Orthostatic (postural) blood pressure/HR measurements The patient should be supine and flat for 5-10 minutes, then the
initial BP and HR are measured The patient is then placed in the sitting position, with feet
dangling. Repeat measurements are taken within 1-3 minutes of position change
Repeat the procedure with the patient in the standing position Record BP and HR, as well as the patient position that
each was taken Be sure to ask about symptoms of dizziness or feeling
faint during position changes - record this as well
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Hemodynamic Monitoring-Invasive
Hemodynamic Monitoring-Invasive
CVP
Pulmonary artery pressure
Intra-arterial BP monitoring
CVP
Pulmonary artery pressure
Intra-arterial BP monitoring
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Hemodynamic MonitoringHemodynamic Monitoring
Critically ill patients may require continuous assessment of their hemodynamic status
Special Equipment: see slide 27
Catheter, which is introduced into the appropriate vessel Flush system for continuous flushing of the catheter Pressure bag around the flush system to prevent
backflow of blood A transducer to convert the pressure from the vessel into
an electrical signal A monitor to display the signal and reading
Critically ill patients may require continuous assessment of their hemodynamic status
Special Equipment: see slide 27
Catheter, which is introduced into the appropriate vessel Flush system for continuous flushing of the catheter Pressure bag around the flush system to prevent
backflow of blood A transducer to convert the pressure from the vessel into
an electrical signal A monitor to display the signal and reading
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Hemodynamic MonitoringHemodynamic Monitoring
Nursing responsibilities Ensuring that the system is set up and
maintained properly Prior to taking a measurement, ensuring that the
stopcock of the transducer is at the level of the right atrium - referred to as the phlebostatic axis (4th intercostal space, midaxillary line
Monitoring for complications
Nursing responsibilities Ensuring that the system is set up and
maintained properly Prior to taking a measurement, ensuring that the
stopcock of the transducer is at the level of the right atrium - referred to as the phlebostatic axis (4th intercostal space, midaxillary line
Monitoring for complications
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Hemodynamic MonitoringHemodynamic Monitoring
Central Venous Pressure Monitoring (CVP) Normal 2-8 mmHg Pressure in the vena cava and right atrium Used to assess right ventricular function and venous blood
return to the right side of the heart Very useful in the assessment of volume status High CVP may indicate volume overload Low CVP may indicate volume depletion
Measured via a central line catheter positioned in the vena cava via the internal jugular or subclavian vein
Central Venous Pressure Monitoring (CVP) Normal 2-8 mmHg Pressure in the vena cava and right atrium Used to assess right ventricular function and venous blood
return to the right side of the heart Very useful in the assessment of volume status High CVP may indicate volume overload Low CVP may indicate volume depletion
Measured via a central line catheter positioned in the vena cava via the internal jugular or subclavian vein
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Phlebostatic LevelPhlebostatic Level
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Hemodynamic MonitoringHemodynamic Monitoring
Central Venous Pressure Monitoring (CVP)-Nursing Interventions Ensure that dressing maintains clean, dry and STERILE Xray confirmation of catheter placement Dressing and pressure monitoring system are maintained according
to hospital policy Monitor for signs of infection Ensure appropriate transducer placement before measurements are
recorded Document CVP Monitor for other complications: pneumothorax, air embolism
Central Venous Pressure Monitoring (CVP)-Nursing Interventions Ensure that dressing maintains clean, dry and STERILE Xray confirmation of catheter placement Dressing and pressure monitoring system are maintained according
to hospital policy Monitor for signs of infection Ensure appropriate transducer placement before measurements are
recorded Document CVP Monitor for other complications: pneumothorax, air embolism
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Hemodynamic MonitoringHemodynamic Monitoring
Pulmonary arterial pressure monitoring (Swan Ganz) Normal PA pressure 20-30/8-15 mmHg; mean 12-18 mmHg Normal pulmonary capillary wedge pressure 6-12 mmHg Used to evaluate right and left sided cardiac function:
Left ventricular performance Volume status Cardiac output Condition of vascular system (SVR) Response to cardiovascular infusions Effects of treatments on cardiac functioning
Inserted via the subclavian or jugular vein, occasionally the femoral vein
Pulmonary arterial pressure monitoring (Swan Ganz) Normal PA pressure 20-30/8-15 mmHg; mean 12-18 mmHg Normal pulmonary capillary wedge pressure 6-12 mmHg Used to evaluate right and left sided cardiac function:
Left ventricular performance Volume status Cardiac output Condition of vascular system (SVR) Response to cardiovascular infusions Effects of treatments on cardiac functioning
Inserted via the subclavian or jugular vein, occasionally the femoral vein
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Hemodynamic MonitoringHemodynamic Monitoring Pulmonary arterial pressure monitoring
Pulmonary artery pressures reflect volume status, right heart function
Pulmonary capillary wedge pressure reflects left heart function ; the catheter is “wedged” in the pulmonary artery and the balloon is inflated , temporarily obstructing blood flow
This creates a static fluid column, and the catheter senses the pressure in the pulmonary vein - this allows us to estimate the left atrial pressure
Pulmonary arterial pressure monitoring Pulmonary artery pressures reflect volume status,
right heart function Pulmonary capillary wedge pressure reflects left
heart function ; the catheter is “wedged” in the pulmonary artery and the balloon is inflated , temporarily obstructing blood flow
This creates a static fluid column, and the catheter senses the pressure in the pulmonary vein - this allows us to estimate the left atrial pressure
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Pulmonary Artery CatheterPulmonary Artery Catheter
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Pulmonary Artery Catheter and Pressure Monitoring System
Pulmonary Artery Catheter and Pressure Monitoring System
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Hemodynamic MonitoringHemodynamic MonitoringNursing responsibilities of a PA catheter:
Ensure that dressing maintains clean, dry and STERILE Xray confirmation of catheter placement Dressing and pressure monitoring system are maintained according to
hospital policy Monitor for signs of infection Ensure appropriate transducer placement before measurements are
recorded Document hemodynamic measurements as ordered During insertion: monitor EKG for dysrhythmias NEVER leave balloon inflated (risk of PA rupture) Monitor for other complications: PA rupture, PA embolism,
pulmonary infarction, catheter migration, dysrhythmias, air embolus, pneumothorax
Nursing responsibilities of a PA catheter: Ensure that dressing maintains clean, dry and STERILE Xray confirmation of catheter placement Dressing and pressure monitoring system are maintained according to
hospital policy Monitor for signs of infection Ensure appropriate transducer placement before measurements are
recorded Document hemodynamic measurements as ordered During insertion: monitor EKG for dysrhythmias NEVER leave balloon inflated (risk of PA rupture) Monitor for other complications: PA rupture, PA embolism,
pulmonary infarction, catheter migration, dysrhythmias, air embolus, pneumothorax
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Hemodynamic MonitoringHemodynamic Monitoring Intra-arterial Blood Pressure Monitoring
Used to obtain direct and continuous BP measurements in critically ill patients
Placed in the radial, femoral or brachial artery
Intra-arterial Blood Pressure Monitoring Used to obtain direct and continuous BP
measurements in critically ill patients Placed in the radial, femoral or brachial artery
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Hemodynamic MonitoringHemodynamic Monitoring Intra-arterial Blood Pressure Monitoring Nursing Interventions
Ensure that dressing remains clean, dry and sterile Ensure patency of pressure monitoring and flushing systems,
maintain per hospital policy Ensure appropriate transducer placement when measurements are
recorded Document BP as ordered Monitor for complications: distal ischemia, hemorrhage, massive
ecchymosis, dissection, air embolism, pain, infection NEVER inject anything into the arterial line
Intra-arterial Blood Pressure Monitoring Nursing Interventions
Ensure that dressing remains clean, dry and sterile Ensure patency of pressure monitoring and flushing systems,
maintain per hospital policy Ensure appropriate transducer placement when measurements are
recorded Document BP as ordered Monitor for complications: distal ischemia, hemorrhage, massive
ecchymosis, dissection, air embolism, pain, infection NEVER inject anything into the arterial line
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Arterial Pressure Monitoring System
Arterial Pressure Monitoring System