title: Blood gases and retinopathy of prematurity: the ELGAN Study.
abstract: OBJECTIVE
  This study tested the hypothesis that preterm infants who had a blood gas derangement on at least 2 of the first 3 postnatal days are at increased risk for more severe retinopathy of prematurity (ROP).
  
  
  METHODS
  1,042 infants born before 28 weeks' gestational age (GA) were included. An infant was considered to be exposed if his/her blood gas measure was in the highest or lowest quartile for GA on at least 2 of the first 3 postnatal days.
  
  
  RESULTS
  Multivariable models adjusting for confounders indicate that exposure to a PCO(2) in the highest quartile predicts ROP (stage 3, 4 or 5: OR = 1.6, 95% CI = 1.1-2.3); zone 1: 2.0, 1.1-3.6; prethreshold/threshold: 1.9, 1.2-3.0; plus disease: 1.8, 1.1-2.9). Estimates are similar for a low pH for zone 1 (2.1, 1.2-3.8), prethreshold/threshold (1.8, 1.1-2.8), but did not quite achieve statistical significance for ROP stage 3, 4, or 5 (1.4, 0.9-2.0) and plus disease (1.5, 0.9-2.4). A PaO(2) in the highest quartile for GA on at least 2 of the first 3 postnatal days was associated with a doubling of the risk of ROP in zone 1 (2.5, 1.4-4.4) and of prethreshold/threshold disease (2.1, 1.4-3.3), a 70% risk increase for plus disease (1.7, 1.04-2.8), while a 40% risk increase for ROP stage 3 or higher did not achieve statistical significance (1.4, 0.96-2.0).
  
  
  CONCLUSIONS
  Infants exposed to high PCO(2), low pH and high PaO(2) appear to be at increased risk of more severe ROP.
authors.affiliation: Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Alisse K
authors.initials: AK
authors.lastname: Hauspurg
authors.forename: Elizabeth N
authors.initials: EN
authors.lastname: Allred
authors.forename: Deborah K
authors.initials: DK
authors.lastname: Vanderveen
authors.forename: Minghua
authors.initials: M
authors.lastname: Chen
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Bednarek
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cole
authors.forename: Richard A
authors.initials: RA
authors.lastname: Ehrenkranz
authors.forename: Alan
authors.initials: A
authors.lastname: Leviton
authors.forename: Olaf
authors.initials: O
authors.lastname: Dammann
mesh_terms: D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D010100:Oxygen / Q000097:blood*; D011247:Pregnancy; D012178:Retinopathy of Prematurity / Q000097:blood*
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen