Lactate Dynamic Changes as a Predictive Tool for Early Primary Graft Dysfunction After Lung Transplantation: A Retrospective Study

Background: Primary graft dysfunction (PGD) is one of the most common and severe complications after lung transplantation. However, beyond the ratio of partial pressure of oxygen to fraction of inspired oxygen, there is a lack of objective clinical or laboratory indicators to guide real-time decision-making during the first 24 hours after surgery. Methods: We retrospectively examined 74 patients who underwent lung transplantation at our center between September 2022 and December 2024. The patients were classified into 2 groups based on the presence or absence of PGD. We analyzed their clinical data and lactate dynamic changes within 24 hours. Results: The PGD group showed significantly higher lactate values at 0 hours (L0, P = .011), 3 hours (L3, P = .001), and 6 hours (L6, P = .001) after intensive care unit admission than the group without PGD. The largest difference occurred at 6 hours. There was no statistically significant difference in lactate levels at 24 hours (L24, P = .139) between the 2 groups. Delta lactate values between 0 and 24 hours (L0-L24) showed no statistically significant difference (P = .096), while the values of L3-L24 and L6-L24 showed statistically significant differences between the 2 groups (P = .015 and P = .002, respectively). Multivariate Cox regression analysis showed that L6-L24 was independently a protective factor for PGD (Wald = 4.227, P = .04). Conclusions: After lung transplantation, a significant increase in 6-hour lactate levels and untimely clearance from 6 to 24 hours are powerful warning signs for the development of PGD.