Comparative study of solutions for pulmonary preservation using an isolated rabbit lung model

At the University of Minnesota, University of Wisconsin (UW), modified Euro-Collins (MEC), and Marshall (M) solutions were compared as agents for pulmonary preservation in an isolated rabbit lung model. Normal saline (NS) was used as a control. The heart-lung blocks of donor rabbits were flushed with, and then preserved in, one of the solutions at 4 degrees C. Five rabbits were studied in each group. After 8 h of cold ischemia, the left lung was ventilated and reperfused with fresh venous blood from donor rabbits for 30 min. Pulmonary function was assessed by serial measurements of oxygen (O2) and carbon dioxide (CO2) tensions in blood obtained from the left atrial appendage. The ratios of wet/dry (W/D) weight of the lungs were calculated to assess the extent of pulmonary edema. After 8 h of preservation followed by 30 min of reperfusion, O2 tension was significantly higher with UW (178.36 + 1.72 mmHg). The calculated P values were UW vs NS, < 0.0001; UW vs MEC, 0.154; and UW vs M, 0.0001. CO2 tension with UW was also lower than the other solutions: UW, 35.8 +/- 0.698 mmHg; NS, 48.5 +/- 0.745 mmHg; MEC, 40.69 +/- 0.749 mmHg; and M, 44.68 +/- 0.697 mmHg. The calculated P value was UW vs NS, 0.0001; UW vs MEC, 0.0003; and UW vs M, 0.0001 using repeated-measures analysis of covariance. The W/D ratio was lower with UW as well; UW, 6.82 +/- 0.19; NS, 8.01 +/- 0.23; MEC, 7.28 +/- 0.10; and M, 7.34 +/- 0.17. The P value was < 0.001 using post-hoc tests. In this model, UW solution preserved the lungs better than the other three solutions tested and therefore warrants further clinical application.