Ringer Lactate Versus Hybrid Isotonic/Hypotonic Saline in Delayed Graft Function in Deceased-donor Kidney Transplantation: A Real-world Protocol Change Study

Background. Delayed graft function (DGF) remains a major complication after deceased-donor kidney transplantation. Balanced crystalloid solutions have been associated with lower DGF incidence compared with 0.9% saline, largely based on strategies using Plasma-lyte. However, the role of Ringer lactate compared with other low-chloride solutions, such as hypotonic saline, remains unclear. We therefore evaluated whether a protocol-driven change in perioperative crystalloid strategy was associated with DGF and early posttransplant kidney function. Methods. We conducted a retrospective, single-center, quasi-experimental study including recipients of deceased-donor kidney transplants. Patients were exposed to a protocol-driven change in perioperative hydration from a hybrid intraoperative 0.9% saline plus postoperative hypotonic saline (0.45%) strategy to an intraoperative and postoperative Ringer’s lactate strategy. The primary outcome was DGF. Secondary outcomes included DGF duration, longitudinal kidney function, electrolyte trajectories, and 12-mo clinical outcomes. Generalized additive mixed models were used to evaluate longitudinal trajectories of graft function and electrolyte balance while accounting for within-subject variability. Results. A total of 257 kidney transplant recipients were included (142 Ringer lactate; 115 hybrid isotonic/hypotonic saline), with comparable baseline characteristics. DGF incidence did not differ between groups (47.9% Ringer lactate versus 52.2% hybrid isotonic/hypotonic; P = 0.49), nor did days to renal graft recovery (5.7 versus 5.7 d; P = 0.96) or DGF duration (10.5 versus 10.2 d; P = 0.78). Mortality, graft loss, and biopsy-proven rejection at 12 mo were also similar. In covariate-adjusted longitudinal analyses, the estimated glomerular filtration rate did not differ between groups. Electrolyte trajectories showed modest differences between groups. Conclusions. In this real-world quasi-experimental study, Ringer lactate was not associated with lower DGF incidence or duration compared with a hybrid isotonic/hypotonic saline-based strategy. No differences were also observed in graft function over the 12-mo follow-up. These findings support further investigation into whether differences in chloride exposure may influence early graft outcomes.