Copyright © 2008 Lippincott Williams & Wilkins. 1 Assessment of Cardiovascular Function Hemodynamic Monitoring

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Copyright © 2008 Lippincott Williams & Wilkins.

Assessment of Cardiovascular Function

Assessment of Cardiovascular Function

Hemodynamic Monitoring

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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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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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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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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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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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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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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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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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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

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Copyright © 2008 Lippincott Williams & Wilkins. 1 Assessment of Cardiovascular Function Hemodynamic Monitoring