Calculate the systemic vascular resistance (SVR) given CO 5.0 L/min, CVP 8 mm Hg, MAP 86 mm Hg.

Calculate the systemic vascular resistance (SVR) given CO 5.0 L/min, CVP 8 mm Hg, MAP 86 mm Hg.

• A. 750
• B. 1000
• C. 1250
• D. 1500

Answer: (C)

Systemic vascular resistance is the pressure the heart must overcome to drive blood through the systemic circulation, expressed as a resistance calculated from the pressure gradient across the systemic bed divided by the cardiac output, with a conversion to standard units. Use the mean arterial pressure minus the central venous pressure (or right atrial pressure) to represent that pressure gradient. Here, the gradient is MAP minus CVP = 86 − 8 = 78 mm Hg. Divide by the cardiac output: 78 / 5 = 15.6. Multiply by 80 to convert to dynes·sec·cm⁻⁵: 15.6 × 80 = 1248, roughly 1250 dynes·sec·cm⁻⁵.

Systemic vascular resistance is the pressure the heart must overcome to drive blood through the systemic circulation, expressed as a resistance calculated from the pressure gradient across the systemic bed divided by the cardiac output, with a conversion to standard units. Use the mean arterial pressure minus the central venous pressure (or right atrial pressure) to represent that pressure gradient.

Here, the gradient is MAP minus CVP = 86 − 8 = 78 mm Hg. Divide by the cardiac output: 78 / 5 = 15.6. Multiply by 80 to convert to dynes·sec·cm⁻⁵: 15.6 × 80 = 1248, roughly 1250 dynes·sec·cm⁻⁵.