A Donor PO 2 /FiO 2 Less Than 300 Does Not Determine Graft Function or Survival After Lung Transplantation

ABSTRACT Background A donor arterial PO2/FiO2 (P/F ratio) less than the 300 threshold would frequently result in either exclusion of the donor or placement of the lungs on ex-vivo lung perfusion (EVLP). The aim was to investigate the veracity of the P/F ratio threshold of 300 for donor lung acceptability. Methods In 93 brain dead lung donors, arterial blood gases were drawn in the intensive care unit (ICU) just prior to procurement and each of the four donor pulmonary veins in the operating room (OR). No donor lungs were rejected for transplantation based on the last ICU or OR P/F ratio and EVLP was not used. Recipients were followed up 6 and 12 months following transplantation. Results There were 93 recipients of bilateral lung transplantation. An arterial P/F ratio of less than 300 was largely driven by a low P/F ratio in the lower lobes. There were no differences between recipients receiving donor lungs where the ICU P/F ratio was less than 300 compared to greater than or equal to 300 in time to extubation, grade of primary graft dysfunction, pulmonary function at 6 and 12 months, and 12-month survival. Conclusions From this study: 1. If a donor P/F threshold of 300 was adhered to, 36% would have been rejected. 2. The donor P/F ratio threshold of 300 is excessively conservative and results in wastage of donor lungs and the application of unnecessary EVLP.