Critical Serum Creatinine Values in Very Preterm Newborns

Abstract

BackgroundRenal failure in neonates is associated with an increased risk of mortality and morbidity. But critical values are not known.ObjectiveTo define critical values for serum creatinine levels by gestational age in preterm infants, as a predictive factor for mortality and morbidity. Study DesignThis was a retrospective study of all preterm infants born before 33 weeks of gestational age, hospitalized in Nantes University Hospital NICU between 2003 and 2009, with serum creatinine levels measured between postnatal days 3 to 30. Children were retrospectively randomized into either training or validation set. Critical creatinine values were defined within the training set as the 90th percentile values of highest serum creatinine (HSCr) in infants with optimal neurodevelopmental at two years of age. The relationship between these critical creatinine values and neonatal mortality, and non-optimal neural development at two years, was then assessed in the validation set.Results and ConclusionThe analysis involved a total of 1,461 infants (gestational ages of 24-27 weeks (n=322), 28-29 weeks (n=336), and 30-32 weeks (803)), and 14,721 creatinine assessments. The critical values determined in the training set (n=485) were 1.6, 1.1 and 1.0 mg/dL for each gestational age group, respectively. In the validation set (n=976), a serum creatinine level above the critical value was significantly associated with neonatal mortality (Odds ratio: 8.55 (95% confidence interval: 4.23-17.28); p<0.01) after adjusting for known renal failure risk factors, and with non-optimal neurodevelopmental outcome at two years (odds ratio: 2.06 (95% confidence interval: 1.26-3.36); p=0.004) before adjustment. Creatinine values greater than 1.6, 1.1 and 1.0 mg/dL respectively at 24-27, 28-29, 30-32 weeks of gestation were associated with mortality before and after adjustment for risk factors, and with non-optimal neurodevelopmental outcome, before adjustment.

Renal outcome in children born preterm with neonatal acute renal failure: IRENEO—a prospective controlled study

“…In the absence of a consensual definition of AKI in preterm babies, we used critical values of serum creatinine levels defined retrospectively, according to gestational age, in children born very preterm with a normal outcome at 2 years of corrected age [28]. Using this definition, we included a few children in the AKI-C group with neonatal creatinine values which would have been considered to be normal by some neonatologists.…”

“…Definition of AKI and matching using a propensity score of AKI In a previous study, we determined critical GA-based serum creatinine values which were strongly correlated to neonatal mortality [28]. These values (1.6 mg/dl for neonates born between 24 and 27 weeks GA; 1.1 mg/dl for those born between 28 and 29 weeks GA and 1.0 mg/dl for those born between 30 and 32 weeks GA) were used to define AKI.…”

“…Indeed, few neonatologists take GA into account in the definition of AKIN, even though GA is a key factor in the evolution of creatinine [20,26,27]. Using neonatal serum creatinine values from children born preterm who had a normal outcome after 2 years, we recently defined critical serum creatinine values according to GA and found these to be strongly associated with outcome [28].…”

The Impact of Kidney Development on the Life Course: A Consensus Document for Action

“…Serum creatinine levels are widely used in the diagnosis of AKI in adults and older children, but its utility in preterm infants is limited by maternal creatinine, immature renal tubule function, and, until recently, the lack of a clear definition of AKI [136,142,399]. A neonatal AKI classification which should improve uniformity of diagnosis and comparability of data across institutions has recently been proposed [136,142,147] (Table 13).…”

Estudio bioquímico en sangre del cordón umbilical de recién nacidos teniendo en cuenta edad gestacional y peso al nacer

“…Numerosos son los valores que la bibliografía consultada reporta para los días siguientes al parto, coincidiendo en que estos disminuyen considerablemente en el primer mes de vida 10,14,17,18 . De manera general no aparecen en la literatura referencias a valores de creatinina en SCU para recién nacidos de bajo peso, ya sean a término o pretérmino.…”