OBJECTIVES: Given the complex interrelatedness of fluid overload (FO), creatinine, acute kidney injury (AKI), and clinical outcomes, the association of AKI with poor outcomes in critically ill children may be underestimated due to definitions used. We aimed to disentangle these temporal relationships in a large cohort of children with acute respiratory distress syndrome (ARDS).

DESIGN: Retrospective cohort study.

SETTING: Quaternary care PICU.

PATIENTS: Seven hundred twenty intubated children with ARDS between 2011 and 2019.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Daily fluid balance, urine output (UOP), and creatinine for days 1-7 of ARDS were retrospectively abstracted. A subset of patients had angiopoietin 2 (ANGPT2) quantified on days 1, 3, and 7. Patients were classified as AKI by Kidney Disease Improving Global Outcomes (KDIGO) stage 2/3 then grouped by timing of AKI onset (early if days 1-3 of ARDS, late if days 4-7 of ARDS, persistent if both) for comparison of PICU mortality and ventilator-free days (VFDs). A final category of "Cryptic AKI" was used to identify subjects who met KDIGO stage 2/3 criteria only when creatinine was adjusted for FO. Outcomes were compared between those who had Cryptic AKI identified by FO-adjusted creatinine versus those who had no AKI. Conventionally defined AKI occurred in 26% of patients (early 10%, late 3%, persistent 13%). AKI was associated with higher mortality and fewer VFDs, with no differences according to timing of onset. The Cryptic AKI group (6% of those labeled no AKI) had higher mortality and fewer VFDs than patients who did not meet AKI with FO-adjusted creatinine. FO, FO-adjusted creatinine, and ANGPT2 increased 1 day prior to meeting AKI criteria in the late AKI group.

CONCLUSIONS: AKI was associated with higher mortality and fewer VFDs in pediatric ARDS, irrespective of timing. FO-adjusted creatinine captures a group of patients with Cryptic AKI with outcomes approaching those who meet AKI by traditional criteria. Increases in FO, FO-adjusted creatinine, and ANGPT2 occur prior to meeting conventional AKI criteria.

<p>Hyponatremia is a common finding in adults hospitalized with heart failure (HF) and is associated with longer hospital stays and increased mortality. The significance of hyponatremia in children with HF is not known. We sought to determine the incidence of hyponatremia and association with clinical outcome in children hospitalized with HF. Admission and inpatient serum sodium concentrations were analyzed in 141 consecutive children hospitalized with acute decompensated HF. Inclusion criteria include patients (age, birth to 21&nbsp;years) with biventricular hearts who were hospitalized for HF from January 2007 to December 2012. The primary composite end point was death, cardiac transplantation, or the use of mechanical circulatory support (MCS) during hospitalization. Data for 141 patients were included in the analysis. The cohort included 48 patients (34%) with preexisting HF. Mean serum sodium at admission was 136 ± 4&nbsp;mmol/L (range 124 to 150&nbsp;mmol/L). Hyponatremia (serum sodium &lt;135&nbsp;mmol/L) was present in 45 patients (32%) at admission. Seventy-one patients (75%) with normal serum sodium concentrations at admission subsequently developed acquired hyponatremia during their hospitalization. Hyponatremia persisted at discharge in 17 of 66 patients (26%). Fifty-eight patients (41%) reached the composite end point during hospitalization (death, n&nbsp;= 15; cardiac transplantation, n&nbsp;= 27; MCS, n&nbsp;= 46). Hyponatremia at admission was independently associated with death, cardiac transplantation, or the use of MCS during hospitalization (odds ratio 3.1, p&nbsp;= 0.02). In conclusion, hyponatremia occurs commonly in children hospitalized with acute decompensated HF and is associated with increased risk of in-hospital mortality, cardiac transplantation, and need for MCS.</p>