Acute Kidney Injury in Premature, Very Low-Birth-Weight Infants

Abstract

The epidemiology of neonatal acute kidney injury (AKI) is not well established, partly due to lack of a consensus definition. Preterm neonates are likely especially vulnerable to AKI. We performed a retrospective review to assess the incidence of and risk factors for AKI in very low-birth-weight (VLBW), premature infants admitted to a level 4 NICU (2006?2007). AKI was classified using a standardized definition based on changes in serum creatinine (SCr). AKI incidence varied inversely with gestational age (GA): 65% (22?25 weeks), 25% (26?28 weeks), 9% (29?32 weeks) as did severity (p?<?0.001). Stage 1 AKI was most common in each cohort. Stages 2 and 3 AKI comprised approximately 60% of AKI in the 22- to 25-week cohort but 20% or less in the older cohorts. By univariate analysis, factors associated with AKI included younger GA, lower BW, lower Apgar scores, hypotension, more frequent treatment with nephrotoxic antimicrobials, longer-duration mechanical ventilation, and higher incidence of patent ductus arteriosus (PDA) requiring treatment. By multiple logistic regression analysis, only GA, hypotension, PDA, and longer duration of mechanical ventilation were independently associated with AKI. AKI was not independently associated with risk of death. Our study suggests that small increases (? 0.3 mg/dL) in SCr occur frequently in premature, VLBW infants, and are associated with increased morbidity but not mortality. AKI incidence and severity were highest in the youngest GA cohort. Understanding the epidemiology, risk factors, and impact of neonatal AKI is crucial as long-term premature infant survival continues to improve.

A Prediction Nomogram for Acute Kidney Injury in Very-Low-Birth-Weight Infants: A Retrospective Study

“…This study revealed that early GA was significantly associated with an increased risk of AKI in VLBW infants. This finding is consistent with the observations by Carmody et al ( 8 ) and Mian et al ( 10 ). This may be attributed to the fact that the earlier the GA, the lesser is the number of nephrons and their maturity ( 23 ), which leads to an increased susceptibility toward kidney injury ( 24 ).…”

“…Therefore, the incidence of AKI has been reported to be high, at 12–40% ( 5 – 8 ), which makes it particularly important to identify the potential predictors for AKI and develop a risk prediction model for the early detection of AKI in VLBW infants ( 9 ). Mian et al retrospectively analyzed the clinical data of a cohort of 266 VLBW infants and found that early gestational age (GA), patent ductus arteriosus (PDA), and prolonged mechanical ventilation were independent predictors for AKI in VLBW infants ( 10 ). Al Malla et al in their retrospective study of 293 VLBW infants, observed that necrotizing enterocolitis (NEC) was an independent predictor for AKI in VLBW infants ( 5 ).…”

Urine Output Monitoring for the Diagnosis of Early-Onset Acute Kidney Injury in Very Preterm Infants

“…Single-center studies have reported rates of AKI from 12% to 40%, and only the creatinine criterion was used in most of the series, which is in contradiction with the methodology behind the neonatal KDIGO AKI definition (16)(17)(18). In the recently published multicentric Extremely Low Gestational Age Newborns study, which included 923 extreme preterm neonates (,28 weeks), the prevalence of early-onset AKI was low (12%) (19).…”

Severe Acute Kidney Injury and Mortality in Extremely Low Gestational Age Neonates

“…Although most studies confirm the association between AKI and mortality, a retrospective cohort study of 266 premature (<32 weeks gestation) and very low birthweight (<1500 g) neonates found no such association (13). The incidence of AKI in this study was higher than we report, with 65% of 22–25-week extremely low gestational age neonates developing AKI, and 25% of neonates born at a gestational age of 26–28 weeks.…”