Major adverse kidney events after acute kidney injury in the pediatric intensive care unit: a propensity score-matched cohort study

Abstract

Background: Acute kidney injury (AKI) in patients admitted to the pediatric intensive care unit (PICU) is associated with poor short-term and long-term outcomes. Greater awareness of long-term AKI-associated outcomes is needed to optimally plan follow-up and management after ICU discharge. We used propensity score methods to study associations between pediatric AKI and major adverse kidney outcomes, including mortality.

Methods: We included all children 6 months-18 years admitted to PICU at Seattle Children's Hospital from 7/1/2009 to 12/31/2018. Our primary outcome measure was Major Adverse Kidney Events at 30 days (MAKE30): creatinine > 200% of baseline, eGFR < 60 mL/min/1.73 m², dialysis dependence, or mortality. Propensity scores for AKI development in PICU were generated using demographic, medical history, admission, and PICU hospitalization variables. Patients with AKI were matched to control patients without AKI. Logistic regression was used to test association between AKI status and MAKE30.

Results: In the unmatched cohort (n = 878), patients with AKI had lower platelet count (160 vs. 222) and higher PRISM III score (11 vs. 3.5). After propensity score matching, those with AKI vs. no AKI had similar PRISM III scores (9 vs. 10) and platelet count (163 vs. 159). AKI was significantly associated with MAKE30 after propensity score matching (OR: 2.97; 95% CI 1.82-4.84).

Conclusions: Propensity score matching significantly reduced imbalance in baseline characteristics between those with and without AKI. After matching, AKI remained significantly associated with MAKE30. Patients who developed AKI were more likely to have abnormal kidney function at 30 and 90 days after ICU admission and may be at high risk for developing CKD in the future. A higher resolution version of the Graphical abstract is available as Supplementary information.

Keywords: Acute kidney injury; Long-term adverse effects; Observational study; Pediatric intensive care medicine; Pediatrics; Propensity score.