Abstract |
Background: Acute kidney injury (AKI) occurs commonly in critically ill children hospitalized in
Pediatric Intensive Care Units (PICU). AKI is associated with poor short-term and long-term
outcomes such as increased duration of mechanical ventilation, prolonged hospitalization,
proteinuria, increased risk of chronic kidney disease and death. Recently, fluid overload (FΟ)
was associated with AKI and poor prognosis. AKI and FO share a bidirectional risk. AKI is a risk
factor for FO and fluid accumulation is a risk factor for AKI. When these two phenomena act
simultaneously, patients face greater risk of poor outcomes. Management of AKI is based on
supportive care since there is no efficient therapeutic intervention. Early recognition of AKI
and identification of patients at risk of AKI led to the idea of “renal angina” (RA) and the
introduction of “Renal Angina Index” (RAI) as a validated measurement of RA that combines
patient-specific risk factors as well as early signs of renal dysfunction. RAI is scored at hospital
admission and is evaluated on its capacity to predict AKI 3 days after admission. Lacking
sufficient tools for detecting FO, RAI is also investigated as a predictor of FO.
Objective: The purpose of this study is to evaluate RAI as a predictor of acute kidney injury
and fluid overload in critically ill children. Simultaneously it is of great importance to compare
RAI’s performance with traditional RAI markers and investigate the relation of RAI with risk
factors and clinical signs of AKI, markers of illness severity and markers of outcome.
Methods: This study was conducted in the University Hospital of Heraklion PICU. Data were
collected retrospectively from medical records of patients admitted between January 2018
and November 2022. Data collection form contained demographic and clinical information,
illness- severity indices, markers of outcome, presence or absense of AKI (KDIGO), fluid
accumulation (FO) and therapeutic interventions.
Results: A total of 200 critically ill children were included, with a mean age of 4,7 years. The
vast majority (63,5%) were males, 63% (n=126) were mechanicaly ventilated, 23% (n=46) had
comorbidities and total AKI incidence was 19,5% (n=39). Crude mortality was estimated at 8%
(n=16) and associated with older age (p=0.039), comorbidities (p=0.013), higher PIM-III score
(p=0.001), longer duration of PICU and in-hospital stay (p=0.001) and longer duration of
mechanical ventilation (p<0.006). RAI (+)>8 was independently associated with the duration
of mechanical ventilation (p=0.012), AKI (p=0.034, p=0.001) and FO development (p=0.002) 3
days after PICU admission. Also, the positive index was related with Multiple Organ Dysfunction Syndrome (MODS), use of diuretics, vasoactive support, longer duration of PICU
and in-hospital stay and higher mortality (all, p<0.001). RAI appeared to be non-inferior at
prediction of AKI (all stage and severe) compared to traditional AKI markers, however did not
manage to predict FO 3 days after PICU admission.
Conclusion: Positive RAI was independentely associated with the imminent AKI and FO in
PICU patients. Its ability on AKI prediction was found to be decent and equal to traditional AKI
biomarkers although it didn’t manage to predict FO. RAI (+) was associated with risk factors
of AKI (mechanical ventilation, inotropes), markers of illness severity (PIM III score), multiple
organ dysfunction syndrome (MODS), FO and markers of outcome such as PICU length of stay
and in-hospital stay. RAI is a valuable and costless index of AKI and FO development in
patients hospitalized in a PICU. Further studies are needed in critically ill or traumatized
children to evaluate RAI’s application in clinical everyday practice and its effect on children’s
outcome.
|