title: Critical serum creatinine values in very preterm newborns.
abstract: BACKGROUND
  Renal failure in neonates is associated with an increased risk of mortality and morbidity. But critical values are not known.
  
  
  OBJECTIVE
  To define critical values for serum creatinine levels by gestational age in preterm infants, as a predictive factor for mortality and morbidity.
  
  
  METHODS
  This 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 90(th) 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.
  
  
  CONCLUSIONS
  The 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.
authors.affiliation: Department of Pediatrics, Nantes University Hospital, University of Nantes, Nantes, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Bruel
authors.affiliation: Department of Neonatalogy, Nantes University Hospital, University of Nantes, Nantes, France ; INSERM, CIC 004, Nantes University Hospital, Nantes, France ; INRA, Nantes University Hospital, UMR 1280 Physiologie des adaptations nutritionnelles, Nantes, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Rozé
authors.affiliation: Department of Neonatalogy, Nantes University Hospital, University of Nantes, Nantes, France ; INSERM, CIC 004, Nantes University Hospital, Nantes, France ; INRA, Nantes University Hospital, UMR 1280 Physiologie des adaptations nutritionnelles, Nantes, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Flamant
authors.affiliation: Department of Neonatalogy, AP-HM & Aix-Marseille University, Marseille, France.
authors.forename: Umberto
authors.initials: U
authors.lastname: Simeoni
authors.affiliation: Department of Pediatrics, Nantes University Hospital, University of Nantes, Nantes, France.
authors.forename: Gwenaëlle
authors.initials: G
authors.lastname: Roussey-Kesler
authors.affiliation: Department of Pediatrics, Nantes University Hospital, University of Nantes, Nantes, France.
authors.forename: Emma
authors.initials: E
authors.lastname: Allain-Launay
mesh_terms: D003404:Creatinine / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D062071:Infant, Extremely Premature / Q000097:blood*; D007231:Infant, Newborn; D008297:Male; D051437:Renal Insufficiency / Q000097:blood* / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D003404:Creatinine