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CHAPTER 15. Hemodynamic Measurements. HEMODYNAMIC MEASURMENTS DIRECTLY OBTAINED BY MEANS OF THE PULMONARY CATHETER. Insertion of Pulmonary Catheter. Fig. 15-1. Insertion of Pulmonary Catheter. Hemodynamic Values Directly Obtained by Pulmonary Artery Catheter. Table 5-1.
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CHAPTER 15 Hemodynamic Measurements
HEMODYNAMIC MEASURMENTS DIRECTLY OBTAINED BY MEANS OF THE PULMONARY CATHETER
Insertion of Pulmonary Catheter • Fig. 15-1. Insertion of Pulmonary Catheter.
Hemodynamic Values Directly Obtained by Pulmonary Artery Catheter Table 5-1
Computed Hemodynamic Values Table 15-1
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
Stroke Volume (SV) • SV is derived by dividing the cardiac output (CO) by the heart rate
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:
Factors Increasing and Decreasing SV, SVI, CO, CI, RVSWI, and LVSWI Table 15-3
Factors Increasing and Decreasing SV, SVI, CO, CI, RVSWI, and LVSWI Table 15-3
Stroke Volume Index (SVI) • SVI is derived by dividing the SV by the body surface area (BSA)
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:
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: • Contractility of the heart • Overall blood volume status • Amount of venous return • See Table 15-3
Cardiac Index (CI) • CI is calculated by dividing the CO by the body’s surface area (BSA)
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
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
Right Ventricular Stroke Work Index (RVSWI) • Derived from the following formula:
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)
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
Right Ventricular Stroke Work Index (RVSWI) • The LVSWI is derived from the following formula:
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:
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
Pulmonary Vascular Resistance (PVR) • PVR measurement reflects afterload of right ventricle. • It is calculated by the following formula:
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)
Factors that Increase Pulmonary Vascular Resistance (PVR) Table 15-4
Factors that Increase Pulmonary Vascular Resistance (PVR) Table 15-4
Factors that Decrease Pulmonary Vascular Resistance Table 15-5
Systemic or Peripheral Vascular Resistance (SVR) • SVR measurement reflect the afterload of the left ventricle. It is calculated by the following formula:
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:
Factors that Increase and Decrease Systemic Vascular Resistance (SVR) Table 15-6