Pearse and Sylvester (A-23) conducted a study to determine the separate contributions of ischemia and extracorporeal perfusion to vascular injury occurring in isolated sheep lungs and to determine the oxygen dependence of this injury. Lungs were subjected to ischemia alone, extracorporeal perfusion alone, and both ischemia and extracorporeal perfusion. Among the data collected were the following observations on change in pulmonary arterial pressure (mm Hg) and pulmonary vascular permeability assessed by estimation of the reflection coefficient for albumin in perfused lungs with and without preceding ischemia:

Ischemic–Perfused Lungs Perfused Lungs Change in Pulmonary Pressure Reflection Coefficient Change in Pulmonary Pressure Reflection Coefficient 8.0 0.220 34.0 0.693 3.0 0.560 31.0 0.470 10.0 0.550 4.0 0.651 23.0 0.806 48.0 0.999 15.0 0.472 32.0 0.719 43.0 0.759 27.0 0.902 18.0 0.489 25.0 0.736 27.0 0.546 25.0 0.718 13.0 0.548 0.0 0.467 Source: Data provided courtesy of Dr. David B. Pearse.