Acute kidney injury (AKI) in neonates.
Review the definition, risk factors, pathogenesis, clinical symptoms, diagnosis, outcomes, and clinical management of neonatal AKI.
AKI is a challenging and frequent condition in the neonatal intensive care unit (NICU).
While the definition of AKI in the neonate is controversial, one or more of the following indicate the presence of AKI: an elevated serum creatinine (SCr) for gestational age, an increase in SCr to 1.5 times the baseline value or higher, an increase in SCr by 0.3 mg/dL over 48 hours, or decrease in urine output (UOP). It should be noted that SCr has limitations as a biomarker for AKI including a 48- to 72-hour lag in rise after injury to the kidneys, presence of maternal creatinine at birth, and varying degrees of reabsorption in the proximal renal tubules. Research to identify other biomarkers for AKI is ongoing, but SCr remains the best accepted criterion at present. Table 59.1 lists the complete criteria for diagnosis of neonatal AKI.
TABLE 59.1.Proposed Neonatal AKI Definition Modifications from KDIGO Pediatric AKI Definition Using Scr and Urine Output Criteria ||Download (.pdf) TABLE 59.1. Proposed Neonatal AKI Definition Modifications from KDIGO Pediatric AKI Definition Using Scr and Urine Output Criteria
|Stage ||Serum Creatinine Criteria (in mg/dL) ||Urine Output Criteria (in mL/kg/h)* |
|Pediatric Definition ||Neonatal Modification 2012 ||Neonatal Modification 2015−2016 ||Pediatric Definition ||Neonatal Modification 2013 ||Neonatal Modification 2016 |
|1 ||≥0.3 rise within 48 h or ≥1.5–1.9 × rise from baseline† within 7 days ||≥0.3 rise or ≥1.5–1.9 × rise from baseline (defined as previous lowest/trough value) ||>0.3 rise within 48 h or >1.5–1.9 × rise from baseline (previous lowest value) within 7 days ||<0.5 for 8 h ||<1.5 for 24 h ||<1 for 24 h |
|2 ||≥2–2.9 × rise from baseline ||Unchanged ||Unchanged ||<0.5 for ≥16 h ||<1 for 24 h ||≤0.5 for 24 h |
|3 ||≥3 × rise from baseline or ≥4.0 or eGFR<35 mL/min per 1.73 m2 or RRT initiation ||≥3 × rise from baseline or ≥2.5 or RRT initiation ||≥3 × rise from baseline or ≥2.5 or RRT initiation ||<0.3 for ≥24 h or anuria for ≥12 h ||<0.7 for 24 h or anuria for 12 h ||≤0.3 for 24 h |