Intraoperative Hypotension and Delayed Graft Function after Kidney Transplantation: A Retrospective Cohort Analysis

Background: Delayed graft function is a major postoperative complication after kidney transplantation, increasing the risk of both early and late graft loss. Although many preoperative, surgical, and donor-related risk factors are unmodifiable, intraoperative hypotension may contribute to reduced kidney perfusion and affect delayed graft function incidence. However, the impact of intraoperative hypotension on the risk of delayed graft function has not been rigorously examined. It was hypothesized that intraoperative hypotension is associated with increased odds of delayed graft function after kidney transplantation. Methods: This single-center retrospective cohort study included all consecutive patients with chronic renal failure who underwent first kidney transplantation from a deceased or living donor between 2013 and 2024. Combined transplant procedures were excluded. Intraoperative hypotension was quantified as the area under the curve (AUC) for a mean arterial pressure (MAP) less than 65 mmHg, capturing both duration and severity of intraoperative hypotension. The primary outcome was delayed graft function, defined as a dialysis requirement within the first postoperative week. Multivariable logistic regression, adjusting for prespecified clinically chosen recipient, intraoperative, and donor confounders, was used to assess the association between intraoperative hypotension and delayed graft function. Results: Among 3,825 kidney transplants (68% deceased donors, 32% living donors), the median (Q1, Q3) AUC for MAP less than 65 mmHg was 12 (0, 78) mmHg·min. Delayed graft function occurred in 1,007 patients (26.3% of all cases, 37.5% deceased donors, 3.1% living donors). Each 50 mmHg·min increase in AUC for MAP less than 65 mmHg was associated with higher odds of delayed graft function (adjusted odds ratio, 1.08; 95% CI, 1.02 to 1.14; P = 0.009). Conclusions: Greater duration and severity of intraoperative hypotension were associated with increased incidence of delayed graft function after kidney transplantation. Although causality cannot be established, these findings highlight the potential importance of avoiding low pressure in this vulnerable population. Transplant-specific studies, including randomized trials, are needed to determine optimal intraoperative MAP targets and clarify hemodynamic strategies that may improve graft outcomes.