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.