Duke Pathology Professor John Toffaletti, PhD, co‑authored a study titled “Calculating Pulmonary Shunt Fraction Using Standard Clinical Measurements” with Gerald Zavorsky, PhD, a respiratory therapist at the University of California, Davis. It was published in Physiological Reports on March 3, 2026.
The team used routine clinical lab measurements collected from a healthy individual breathing 100% oxygen for 20 minutes. Then, they applied the real‑world measurements to four well‑known equations commonly used to estimate intrapulmonary shunt—the more detailed classic equation and three simpler approximation equations.
Although these equations have existed for many years, they believe this is the first report to walk readers through actual laboratory data and show, step by step, how each equation is used to calculate shunt values. Shunt values quantify the portion of blood flow passing from the right to the left side of the heart without being oxygenated. Their goal was to create a clear, practical teaching example for clinicians, students, and anyone learning how shunt calculations work in practice.