AKI and Mortality in Children Hospitalized With Malnutrition.

Introduction: Acute kidney injury (AKI) is a common complication of pediatric hospitalizations. We evaluated the prevalence of AKI in children hospitalized with acute malnutrition, examined how AKI definitions influence risk stratification, and assessed the performance of the STOP AKI risk score. Methods: We enrolled 185 Ugandan children hospitalized with acute malnutrition. AKI was defined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria based on serial creatinine measurements, with the nadir creatinine during hospitalization as baseline. Because children with malnutrition have low baseline creatinine levels, we evaluated whether applying minimum absolute creatinine thresholds improved identification of clinically meaningful AKI, defined by its association with mortality. Results: The median age was 1.2 years, and 13.5% of children died. KDIGO-defined AKI without a minimum creatinine threshold was not associated with mortality. Applying a minimum absolute creatinine threshold of 0.4 mg/dl to the KDIGO criteria identified AKI in 23.2% of participants and was independently associated with mortality (adjusted odds ratio [OR, aOR]: 4.06, 95% confidence interval [CI]: 1.39-11.84). A threshold of 0.5 mg/dl identified fewer children but predominantly severe AKI. Clinical risk factors included diarrhea, vomiting, and sepsis. The ISN STOP AKI risk score did not discriminate AKI risk (area under the receiver operating characteristic curve [AUROC]: 0.50, 95% CI: 0.40-0.60). Conclusion: AKI is common in children hospitalized with acute malnutrition and is strongly associated with mortality when clinically meaningful creatinine thresholds are applied. Existing AKI risk tools perform poorly in this population, thereby underscoring the need for adapted approaches to AKI identification in malnourished children.