title: PaCO2 in surfactant, positive pressure, and oxygenation randomised trial (SUPPORT).
abstract: OBJECTIVE
  To determine the association of arterial partial pressure of carbon dioxide PaCO2 with severe intraventricular haemorrhage (sIVH), bronchopulmonary dysplasia (BPD), and neurodevelopmental impairment (NDI) at 18-22 months in premature infants.
  
  
  METHODS
  Secondary exploratory data analysis of Surfactant, Positive Pressure, and Oxygenation Randomised Trial (SUPPORT).
  
  
  METHODS
  Multiple referral neonatal intensive care units.
  
  
  METHODS
  1316 infants 24 0/7 to 27 6/7 weeks gestation randomised to different oxygenation (SpO2 target 85-89% vs 91-95%) and ventilation strategies.
  
  
  METHODS
  Blood gases from postnatal day 0 to day14 were analysed. Five PaCO2 variables were defined: minimum (Min), maximum (Max), SD, average (time-weighted), and a four level categorical variable (hypercapnic (highest quartile of Max PaCO2), hypocapnic (lowest quartile of Min PaCO2), fluctuators (hypercapnia and hypocapnia), and normocapnic (middle two quartiles of Max and Min PaCO2)). PaCO2 variables were compared for infants with and without sIVH, BPD and NDI (±death). Multivariable logistic regression models were developed for adjusted results.
  
  
  RESULTS
  sIVH, BPD and NDI (±death) were associated with hypercapnic infants and fluctuators. Association of Max PaCO2 and outcomes persisted after adjustment (per 10 mm Hg increase: sIVH/death: OR 1.27 (1.13 to 1.41); BPD/death: OR 1.27 (1.12 to 1.44); NDI/death: OR 1.23 (1.10 to 1.38), death: OR 1.27 (1.12 to 1.44), all p<0.001). No interaction was found between PaCO2 category and SpO2 treatment group for sIVH/death, NDI/death or death. Max PaCO2 was positively correlated with maximum FiO2 (rs0.55, p<0.0001) and ventilator days (rs0.61, p<0.0001).
  
  
  CONCLUSIONS
  Higher PaCO2 was an independent predictor of sIVH/death, BPD/death and NDI/death. Further trials are needed to evaluate optimal PaCO2 targets for high-risk infants.
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Ambalavanan
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Waldemar A
authors.initials: WA
authors.lastname: Carlo
authors.affiliation: Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, North Carolina, USA.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Wrage
authors.affiliation: Social, Statistical and Environmental Sciences Unit, RTI International, Rockville, Maryland, USA.
authors.forename: Abhik
authors.initials: A
authors.lastname: Das
authors.affiliation: Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Laughon
authors.affiliation: Department of Pediatrics, Duke University, Durham, North Carolina, USA.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Cotten
authors.affiliation: Department of Pediatrics, University of Texas Medical School at Houston, Houston, Texas, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Kennedy
authors.affiliation: Department of Pediatrics, Women and Infants Hospital, Providence, Rhode Island, USA.
authors.forename: Abbot R
authors.initials: AR
authors.lastname: Laptook
authors.affiliation: Department of Pediatrics, Wayne State University, Detroit, Michigan, USA.
authors.forename: Seetha
authors.initials: S
authors.lastname: Shankaran
authors.affiliation: Department of Pediatrics, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Michele C
authors.initials: MC
authors.lastname: Walsh
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Rosemary D
authors.initials: RD
authors.lastname: Higgins
mesh_terms: D015415:Biomarkers / Q000097:blood; D001997:Bronchopulmonary Dysplasia / Q000453:epidemiology / Q000209:etiology; D002245:Carbon Dioxide / Q000097:blood*; D002543:Cerebral Hemorrhage / Q000453:epidemiology / Q000209:etiology; D002658:Developmental Disabilities / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000150:complications / Q000453:epidemiology; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000097:blood / Q000628:therapy*; D007363:Intensive Care Units, Neonatal; D008297:Male; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D010313:Partial Pressure; D011175:Positive-Pressure Respiration / Q000379:methods*; D011379:Prognosis; D011663:Pulmonary Surfactants / Q000627:therapeutic use*; D014481:United States / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D011663:Pulmonary Surfactants; D002245:Carbon Dioxide
keywords: Intensive Care; Mortality; Neonatology; Neurodisability; Respiratory