CHAPTER 15
Hemodynamic Measurements
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HEMODYNAMIC
MEASURMENTS
DIRECTLY OBTAINED
BY MEANS OF THE
PULMONARY CATHETER
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Insertion of Pulmonary Catheter
Fig. 15-1. Insertion of
Pulmonary Catheter.
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Hemodynamic Values Directly Obtained by Pulmonary
Artery Catheter
Table 5-1
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HEMODYNAMIC VALUES
COMPUTED FROM
DIRECT MEASURMENTS
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Computed Hemodynamic Values
Table 15-1
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Stroke Volume (SV)
• SV is the volume of blood ejected by the
ventricles with each contraction
• Preload, afterload, and myocardial
contractility are major determinants of SV
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Stroke Volume (SV)
• SV is derived by dividing the cardiac
output (CO) by the heart rate
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Stroke Volume (SV)
• For example, if an individual has a
cardiac output of 4.5 L/min (4500
mL/min) and a heart rate of 75 beats/min,
the stroke volume would be calculated as
follows:
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Factors Increasing and Decreasing SV, SVI, CO, CI,
RVSWI, and LVSWI
Table 15-3
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Factors Increasing and Decreasing SV, SVI, CO, CI,
RVSWI, and LVSWI
Table 15-3
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Stroke Volume Index (SVI)
• SVI is derived by dividing the SV by the
body surface area (BSA)
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Stroke Volume (SVI)
• For example, if a patient has a stroke
volume of 60 mL and a body surface area
of 2 m2, the SVI would be determined as
follows:
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Stroke Volume (SVI)
• Assuming the heart rate remains the
same, as the SVI increases or
decreases, the CI also increases or
decreases.
• The SVI reflects:
1. Contractility of the heart
2. Overall blood volume status
3. Amount of venous return
• See Table 15-3
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Cardiac Index (CI)
• CI is calculated by dividing the CO by the
body’s surface area (BSA)
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Cardiac Index (CI)
• For example, if a patient has a cardiac
output of 5 L/min and a body surface
area of 2 m2, the cardiac index is
computed as follows:
• See Table 15-3 for a list of factors that increase and decrease the cardiac index
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Right Ventricular Stroke Work Index (RVSWI)
• Measures amount of work required by
right ventricle to pump blood
• Reflects the contractility of right ventricle
• Increases in afterload causes RVSWI to
increase, until plateau is reached
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Right Ventricular Stroke Work Index (RVSWI)
• Derived from the following formula:
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Right Ventricular Stroke Work Index (RVSWI)
• For example, if a patient has an SVI of
35 mL, a PA of 20 mm Hg, and a CVP
of 5 mm Hg, the patient’s RVSWI is
calculated as follows: (next slide)
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Right Ventricular Stroke Work Index (RVSWI)
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Left Ventricular Stroke Work Index (LVSWI)
• Measures amount of work required by left
ventricle to pump blood
• Reflects contractility of the left ventricle
• Increases in afterload causes the LVSWI
to increase, until plateau is reached
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Right Ventricular Stroke Work Index (RVSWI)
• The LVSWI is derived from the following
formula:
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Left Ventricular Stroke Work Index (LVSWI)
• For example, if a patient has an SVI of 30
mL, an MAP of 100 mm Hg, and a PCWP
of 5 mm Hg, then:
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Vascular Resistance
• As blood flows through the pulmonary
and then the systemic vascular system
there is resistance to flow.
– Pulmonary system is a low resistance system
– Systemic vascular system is a high resistance
system
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Pulmonary Vascular Resistance (PVR)
• PVR measurement reflects afterload of
right ventricle.
• It is calculated by the following formula:
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Pulmonary Vascular Resistance (PVR)
• For example, to determine the PVR
of a patient who has a PA of 15 mm Hg,
a PCWP of 5 L/min:
• (Next slide)
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Pulmonary Vascular Resistance (PVR)
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Factors that Increase Pulmonary Vascular Resistance (PVR)
Table 15-4
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Factors that Increase Pulmonary Vascular Resistance (PVR)
Table 15-4
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Factors that Decrease Pulmonary Vascular Resistance
Table 15-5
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Systemic or Peripheral Vascular Resistance (SVR)
• SVR measurement reflect the afterload
of the left ventricle. It is calculated by the
following formula:
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Systemic or Peripheral Vascular Resistance (SVR)
• If a patient has an MAP of 80 mm Hg, a
CVP of 5 mm Hg, and a CO of 5 L/min:
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Factors that Increase and Decrease Systemic Vascular
Resistance (SVR)
Table 15-6
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