Vascular Resistance (SVR & PVR) Calculator
Compute systemic (SVR) and pulmonary (PVR) vascular resistance from mean pressures and cardiac output. Fill the pulmonary fields only if you need PVR.
Formulas
- SVR = (MAP − CVP) ÷ cardiac output × 80 (dynes·s·cm⁻⁵)
- PVR = (mean PAP − PCWP) ÷ cardiac output × 80 (dynes·s·cm⁻⁵)
Normal values
| Resistance | Normal |
|---|---|
| SVR | 800–1200 dynes·s·cm⁻⁵ |
| PVR | < 250 dynes·s·cm⁻⁵ (≈ < 2.5 Wood units) |
A low SVR points to distributive (e.g. septic) shock; see shock hemodynamics.
Frequently asked questions
How do you calculate systemic vascular resistance?
SVR = (mean arterial pressure − central venous pressure) ÷ cardiac output × 80, expressed in dynes·s·cm⁻⁵.
What is a normal SVR?
Roughly 800–1200 dynes·s·cm⁻⁵. A low SVR suggests distributive shock, such as sepsis.
How do you calculate pulmonary vascular resistance?
PVR = (mean pulmonary artery pressure − pulmonary capillary wedge pressure) ÷ cardiac output × 80; normal is under about 250 dynes·s·cm⁻⁵.
Educational tool. These calculators are for study and RCIS exam preparation only — not for clinical decision-making or patient dosing. Always follow institutional protocols and verify with a qualified clinician.