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Heather Pena, BSN, RN, CCRN-CSC
Hemodynamics The study of blood flow or circulation
Monitored primarily through patient assessment
Invasive hemodynamic monitoring via pulmonary artery catheter
Arterial Pressure Monitoring Monitors blood pressure
continuously Systolic blood pressure
Reflects the peak pressure generated by the LV
Diastolic blood pressure
Reflects the lowest pressure in the aorta, just before the ventricle ejects blood
Mean arterial pressure
The average pressure in the arterial system
(systolic pressure + (diastolic pressure x2))/3
http://www.jeffreymlevinemd.com/peripheral-arterial-disease-is-underdiagnosed/
Pulmonary Artery Catheter Types
Continuous cardiac output
Bolus technique of thermodilution
Indications
Vasoactive infusions post-cardiac surgery
Hemodynamic instability
Shock
Multisystem disease
http://instruct.tri-c.edu/dlucas/resp1320/Content/hemodynamics.htm
Pulmonary Artery Catheter Insertion
modernmedicine.com
What can we learn from invasive hemodynamic monitoring? Cardiac Output
Cardiac Index
Central Venous Pressure
Pulmonary Artery Pressure
Mixed Venous Oxygen Saturation
Systemic Vascular Resistance
Pulmonary Vascular Resistance
Pulmonary Artery Wedge Pressure
Cardiac Output The amount of blood pumped by the heart in one
minute
Stroke volume (SV) x heart rate (HR)
Normal measurement: 4-8L/minute
Stroke Volume The amount of blood ejected with each heart beat
(CO x 1000)/HR
Normal measurement: 60-100mL/beat
Cardiac Index A more accurate measure of CO because it takes into
account the patient’s size
CO/BSA
Normal measurement: 2.5-4L/minute/m2
Central Venous Pressure CVP is a direct reflection of right atrial pressure
measured by a PA catheter
Normal measurement: 0-8 mmHg
Evaluates venous return to the heart
CVP
Central Venous Pressure
a = atrial contraction
x = atrial relaxation
c = tricuspid valve closes
v = atrial filling during diastole
Pulmonary Artery Pressure Measured in the pulmonary
artery via PA catheter
Systolic PAP Reflects right ventricular
systolic ejection (the amount of pressure needed to open the pulmonic valve)
Normal measurement: 20-30 mmHg
Diastolic PAP Reflects left ventricular end-
diastolic pressure
Normal measurement: 6-12 mmHg
PA Pressure
Pulmonary Artery Pressure
1 = systolic ejection into pulmonary artery
2 = dicrotic notch (closure of pulmonic valve)
3 = end diastolehttp://www.unpopularmedicine.com/Intensive%20Care/Hemodynamic%20monitoring/
Mixed Venous Oxygen Saturation (SVO2) Measured in the pulmonary artery via PA catheter
Normal measurement: 60-80%
Oxygen saturation of hemoglobin in venous blood that returns to the heart from the tissues.
Systemic Vascular Resistance Represents the resistance that the left ventricle must
pump against to circulate blood through the body
((MAP-CVP)/CO) x 80
Normal measurement: 800-1500 dynes/sec/cm-5
SVR
Pulmonary Vascular Resistance Represents RV afterload, or the pressure the RV has to
push against to flow blood through the pulmonary artery to the lungs
((MAP-PAWP)/CO) x 80
Normal measurement: 155-250 dynes/sec/cm-5
Pulmonary Artery Wedge Pressure Measured by floating the PA catheter more distal in
the pulmonary artery and inflating the balloon so that the PA is occluded.
Normal measurement: 4-12 mmHg
The pressure reflected is that of the left heart.
Pulmonary Artery Wedge Pressure
Preload and Afterload Preload
The amount of stretch in the ventricle before contraction
Afterload
The resistance that the ventricle faces as it attempts to contract
Contractility
The strength of ventricular contraction
Preload and Afterload
Right Heart Left Heart
Preload CVP PA Wedge, PA diastolic
Afterload PA Systolic MAP, SVR
Contractility CI CI
Preload and Afterload
Factor Possible cause Effects on heart
Increased preload Increased fluid volume Increases SV
Vasoconstriction Increases ventricular work
Increases myocardial O2 req.
Decreased preload Hypovolemia Decreases SV
Vasodilation Decreases ventricular work
Decreases myocardial O2 req.
Increased afterload Hypovolemia Decreases SV
Vasoconstriction Increases ventricular work
Increases myocardial O2 req.
Decreased afterload Vasodilation Increases SV
Decreases ventricular work
Decreases myocardial O2 req.