Early post-operative lactate increase following kidney transplant is associated with delayed graft function: A retrospective cohort study.

Introduction: Delayed graft function (DGF) is a frequent complication following kidney transplant. This study aimed to assess the association between early post-operative lactate variation and DGF.

Methods: This was a single center, retrospective cohort study between February 2021 and December 2022 in Saint-Louis Hospital (APHP, France). Venous lactate levels were measured immediately (H0) and 4 h (H4) after kidney transplant. The primary outcome was the occurrence of DGF (need for renal replacement therapy between transplantation and day 7). Secondary outcome was the occurrence of complications (i.e., death, vascular thrombosis, hemorrhagic shock, urological complications (hematoma, urinoma), local or systemic infection) between transplant and day 7.

Results: Two hundred 12 patients were included, and 38 (17.9%) developed DGF. Venous lactate variation between H0 and H4 was higher in patients who developed DGF (-30 (IQR -83, -6)% vs. -15 (IQR -62, -11)%, p = .037), but the variation of level was more often positive (corresponding to an increased lactate production over time between H0 and H4) in patients who developed DGF ((28(85%) vs. 94(62%), p = .011). In multivariate logistic regression, positive venous lactate level variation between H0 and H4 was strongly associated with a reduced risk of developing DGF (OR .30 [.09-.79], p = .024). We did not find any association between post-operative hyperlactatemia and occurrence of complications between transplant and day 7.

Discussion: DGF is a frequent complication following kidney transplantation. Its early prediction could help physicians optimize treatment and protect the kidney. Early venous lactate variation after kidney transplant could help to predict the occurrence of DGF.