Pulmonology · ICU and Critical Care

Physiologic Shunt Fraction (Qs/Qt) calculator

Enter the published formula inputs below to calculate and interpret this score.

Clinical inputs

Pulmonary end-capillary O2 content, CcO2 (mL O2/dL)

vol%

Allowed range: 5–30 vol%

Arterial O2 content, CaO2 (mL O2/dL)

vol%

Allowed range: 5–30 vol%

Mixed venous O2 content, CvO2 (mL O2/dL)

vol%

Allowed range: 1–25 vol%

Result

3 fields remaining

Anyone can run this calculator. Sign in to save, favourite, or send the result.

Ruqelo is AI and can make mistakes. Check important information.

Clinical inputs

Pulmonary end-capillary O2 content, CcO2 (mL O2/dL) (vol%)Accepted range: 5 to 30
Arterial O2 content, CaO2 (mL O2/dL) (vol%)Accepted range: 5 to 30
Mixed venous O2 content, CvO2 (mL O2/dL) (vol%)Accepted range: 1 to 25

Primary source

Berggren SM. The oxygen deficit of arterial blood caused by non-ventilating parts of the lung. Acta Physiol Scand. 1942;4(Suppl 11):1-92. Shunt fraction Qs/Qt = (CcO2 − CaO2)/(CcO2 − CvO2), with end-capillary, arterial and mixed venous oxygen contents in the same units (mL O2/dL = vol%); result × 100 = % of cardiac output. Normal venous admixture is about 3% of cardiac output (Said & Banerjee, J Clin Invest 1963; summarised by Deranged Physiology, Concepts of venous admixture and shunt). (1942)

View source