systemic vascular resistance
Also written as: SVR — Systemic Vascular Resistance
The resistance to blood flow offered by all systemic blood vessels, calculated as mean arterial pressure divided by cardiac output.
Full Definition
Systemic vascular resistance (SVR) represents the total peripheral resistance to blood flow in the systemic circulation. It is calculated by dividing the mean arterial pressure minus central venous pressure by the cardiac output, then multiplying by 80 for units conversion. Normal values range from 800-1200 dynes·sec·cm⁻⁵. During cardiac surgery, SVR monitoring helps guide vasopressor and vasodilator therapy, particularly during separation from cardiopulmonary bypass when patients may develop vasoplegia or excessive vasoconstriction.
Usage
Usage note: Always specify units (dynes·sec·cm⁻⁵) when reporting numerical values.
In Context
- "The patient's systemic vascular resistance dropped precipitously after separation from bypass, requiring norepinephrine infusion." — Operative note
- "SVR calculation revealed elevated afterload necessitating nicardipine administration." — ICU progress note