Estimated Shunt Calculator

Estimates shunt fraction when a mixed venous sample is not available.

Inputs

Color mode links each input to the matching equation term and solving arithmetic.

Equation and Work

Equation:
Solving steps:
Estimated Qsp/Qt
—
%
CcO₂−CaO₂
—
vol%
Severity
—
<10% normal
Normal/reference: Less than 10%. 10–20% mild, 21–30% moderate/significant, >30% severe/critical in the book discussion.

Clinical Significance

Estimates shunt fraction when a mixed venous sample is not available.

This calculator expands that idea by identifying the relevant measured values, substituting the selected inputs, and carrying the arithmetic through in the solving steps.

Provides a shunt estimate when a mixed venous sample is not available.

Less accurate than classic physiologic shunt because mixed venous oxygen content is estimated.

References (APA 7th Edition)

  1. Chang, D. W. (2020). Respiratory Care Calculations (Revised 4th ed.). Jones & Bartlett Learning. Formula content adapted from the uploaded text/reference packet.