title: Oxygen transport in critically ill infants after congenital heart operations.
abstract: BACKGROUND
  Oxygen transport variables reflect the balance of oxygen delivery and demand. Because oxygen transport in infants undergoing congenital cardiac operations is not well described, we examined oxygen transport in such patients. Differences in oxygen transport between survivors and nonsurvivors and variables that might be predictive of outcome were sought.
  
  
  METHODS
  We reviewed hospital records of infants admitted to the pediatric cardiac intensive care unit in our institution from January 1996 through April 1997. Infants in whom simultaneous arterial blood gas and systemic venous oxygen saturation measurements were performed on admission and at 6 and 24 hours after admission were included. Analyses of arterial pH, base excess, arteriovenous oxygen saturation differences, and oxygen extraction ratio were performed, including comparisons of survivors and nonsurvivors and changes over time.
  
  
  RESULTS
  Forty-nine infants were included in the study, with 39 survivors. There were no differences in any parameter between survivors and nonsurvivors on admission or at 24 hours. At 6 hours, differences between survivors and nonsurvivors were significant for arterial pH (7.48 versus 7.35, p<0.001), base excess (2.9 versus -4.3 mmol/L, p<0.01), arteriovenous oxygen saturation difference (34 versus 43, p<0.05), and oxygen extraction ratio (0.28 versus 0.53, p<0.001). The oxygen extraction ratio at 6 hours was at least 0.5 in 6 of 39 survivors and 7 of 10 nonsurvivors (p = 0.002).
  
  
  CONCLUSIONS
  Infants who die after cardiac operations have significant derangements of oxygen transport at 6 hours after admission to the intensive care unit. Infants with an oxygen extraction ratio greater than 0.5 at 6 hours are at highest risk.
authors.affiliation: Department of Pediatrics, The Mount Sinai Medical Center, New York, New York 10029, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Rossi
authors.forename: H S
authors.initials: HS
authors.lastname: Seiden
authors.forename: R P
authors.initials: RP
authors.lastname: Gross
authors.forename: R B
authors.initials: RB
authors.lastname: Griepp
mesh_terms: D016638:Critical Illness; D006330:Heart Defects, Congenital / Q000097:blood / Q000401:mortality / Q000601:surgery*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007231:Infant, Newborn; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D010100:Oxygen