Intraoperative renal oxygen saturation trajectories are associated with early postoperative acute kidney injury after liver transplantation

Acute kidney injury (AKI) is frequent after liver transplantation, yet kidney-specific real-time intraoperative monitoring is limited. We hypothesized that intraoperative renal regional oxygen saturation (rSkO₂) trajectories—particularly a rapid decline—are independently associated with AKI within 7 days after liver transplantation. In this single-center prospective cohort (January 2022–January 2024), adults undergoing liver transplantation with baseline eGFR ≥ 60 mL/min/1.73 m² and total bilirubin ≤ 300 µmol/L underwent continuous bilateral renal near-infrared spectroscopy monitoring (INVOS 5100 C). Latent growth mixture modelling classified rSkO₂ trajectories and derived a rapid-decline threshold (> 22.6% drop within 5 min). The primary endpoint was KDIGO 2012 creatinine-defined AKI within 7 days. Among 185 liver transplant recipients, a rapid renal rSkO₂ drop (> 22.6% within 5 min) occurred in 32 (17%). Patients with a rapid drop had a higher risk of 7-day AKI than those without (66% vs. 30%), and the rapid drop was independently associated with AKI (adjusted OR 8.54, 95% CI 2.97–24.57). A rapid intraoperative renal rSkO₂ decline was associated with a higher risk of early postoperative AKI after liver transplantation and may help identify patients at increased perioperative renal risk.