Lung preservation threshold in a compromised septic lung injury model

Background. Discrepancy between clinical and research works in lung transplantation could be due to differences between compromised clinical donor lungs and intact research lungs. The purpose of this laboratory study was to produce compromised lungs to compare with normal ones. Methods. Sprague-Dawley rats were continuously infused with lipopolysaccharide (5 mg/kg) for 24 hours before organ harvest. Lungs were stored in University of Wisconsin solution at 4°C for the following period: group 1: intact lungs, no storage (n = 12); group 2: septic lungs, no storage (n = 6); group 3: septic lungs for 6 hours (n = 5); and group 4: septic lungs for 12 hours (n = 5). All lungs were reperfused for 2 hours with venous blood using an isolated, pulsatile perfused lung system. Results. Experimental variables were comparable between groups 1, 2, and 3. All septic lungs stored for 12 hours (group 4) failed within 1 hour of perfusion. Conclusions. These results indicate that compromised lungs with septic injury functioned at near control levels after 6 hours of preservation. Six hours may be a safe limit for human donor lungs, all of which are compromised in some way by the time of harvest.