Postoperative physiological parameters associated with severe acute kidney injury after pediatric heart transplant

Background The primary objective was to evaluate associations between perioperative clinical variables and postoperative hemodynamic indices after HT with the development of severe AKI. The secondary objective was to evaluate associations between UOP or creatinine as AKI indicators and morbidity after HT. Methods Retrospective study of all patients who underwent HT 1/2016‐11/2019 at a quaternary pediatric institution. Severe AKI was defined as KDIGO stage 2 or higher. Results Of 94 HT patients, 73 met inclusion criteria; 45% of patients developed severe AKI. In univariate analysis, non‐Hispanic Black race, preoperative AKI, longer CPB duration, lower weight, and peak lactate within 12 h post‐HT were associated with severe AKI. CVP ≤12 h post‐HT had a quadratic relationship, rather than linear, with severe AKI. PPV >18% was significantly associated with severe AKI but equated to noncontiguous 10 min of high variation over a 12‐h period, and thus was deemed not clinically significant. In multivariate analysis, Black race, longer CPB duration, and higher CVP remained associated with severe AKI (c: 0.84, 95% CI 0.73–0.92). Severe AKI per creatinine, but not UOP criteria, was associated with longer duration of ventilation (p = .012) and longer intensive care unit length of stay (p = .003). Conclusions In pediatric HT patients, non‐Hispanic Black race, longer CPB time, and higher postoperative CVP ≤12 h post‐HT were associated with severe AKI. AKI based on creatinine, not UOP, was associated with postoperative HT morbidity.