The Effect of Perfusate Temperature on Delayed Graft Function in Deceased Donor Renal Transplantation

Introduction: Renal allograft hypothermic machine perfusion results in a decreased incidence of delayed graft function compared with static cold storage. Ensuring perfusate temperatures remain within the target range of 4-10 degrees C may impact delayed graft function rates. Project Aims: To identify whether this target was achieved and, if not, whether higher perfusate temperature was associated with delayed graft function. Design: In this retrospective cohort study, transplanted grafts from deceased donors placed on hypothermic machine perfusion pump from June 2019 to August 2020 were analyzed. Measurements were recovered after 5, 15, 60, and 180 min of perfusion. Univariable and multivariable analyses were performed to identify predictors of delayed graft function. Results: A total of 113 grafts from 94 donors were analyzed. Of these, 21 (19%) developed delayed graft function. On univariable logistic regression, variables associated with delayed graft function included older donor age (OR 1.08, P = .002), higher Kidney Donor Profile Index score (OR 1.03, P = .024), and higher 5-min perfusate temperature (T5 min; OR 1.49, P = .014). A higher T5 min was also associated with delayed graft function in multivariable logistic regression models (OR 1.58, P = .005; OR 1.37, P = .08). Grafts with T5 min >10 degrees C were more likely to experience delayed graft function than those with T5 min <10 degrees C (OR 4.5, P = .006). Conclusion: Higher early perfusate temperature was an independent predictor of delayed graft function and may be due to inadequate cooling of the circuit prior to placing grafts on pump. Quality improvement initiatives targeting early perfusate temperatures of <= 10 degrees C may reduce delayed graft function incidence.