Furosemide Stress Test Implementation and Outcomes in Critically Ill Children at High Risk for Acute Kidney Injury: A Hybrid Study

Acute kidney injury (AKI) is common in critically ill children, and continuous renal replacement therapy (CRRT) is a mainstay of treatment for severe AKI. Delayed initiation of CRRT is associated with worse outcomes, but because CRRT carries risks, tools are needed to identify which patients will truly benefit from early initiation. Through previous work, the investigators have developed, tested, and integrated an AKI risk-stratification tool (the Renal Angina Index, RAI) and a urine biomarker (neutrophil gelatinase-associated lipocalin, NGAL) to identify patients at risk for developing severe AKI. The furosemide stress test (FST), previously validated in adults, measures urine output after a standardized dose of furosemide and may help predict which patients will receive dialysis versus those who can be managed medically. However, despite existing clinical decision support, fewer than half of eligible patients currently undergo an FST, suggesting that implementation varies by clinician preference rather than patient factors.

The investigators will follow a cohort of patients admitted to the PICU who are identified as being at high risk for developing severe AKI through RAI and NGAL screening. Using a hybrid type 1 effectiveness-implementation design, the aim is to develop and implement a clinical decision support intervention that standardizes FST use in this population, evaluate whether this intervention is acceptable and feasible to clinicians, and determine its impact on patient outcomes. Outcomes in the two years after implementation will be compared with the two years before, with the primary outcome of reducing fluid overload. The investigators will also assess whether urine flow rate after the FST predicts receipt of CRRT and confirm that performing the FST does not increase the need for blood-pressure support.