title: A Multicenter, Randomized, Controlled Phase IIb Trial of Avoidance of Hyperoxemia during Cardiopulmonary Bypass.
abstract: Cardiac surgery utilizing cardiopulmonary bypass (CPB) is one of the most common forms of major surgery. Cardiac surgery-associated multiorgan dysfunction (CSA-MOD) is well recognized and includes acute kidney injury (AKI), hepatic impairment, myocardial damage, and postoperative neurologic deficit. Pathophysiology of CSA-MOD involves numerous injurious pathways linked to the use of CPB including oxidative stress and formation of reactive iron species. During cardiac surgery with CPB, arterial return blood is oxygenated to supranormal levels. This study aimed to determine whether the avoidance of arterial hyperoxemia decreased oxidative stress and reduced the severity of the multiorgan dysfunction in patients undergoing cardiac surgery utilizing CPB.
  
  
  
  The study was a multicenter, open-label, parallel-group, randomized controlled study of the avoidance of arterial hyperoxemia versus usual care in patients undergoing cardiac surgery involving CPB. Primary outcome was the incidence and severity of AKI. Secondary outcomes included serum biomarkers for CSA-MOD, duration of mechanical ventilation, and length of intensive care and hospital stay.
  
  
  
  A total of 298 patients were randomized and analyzed at two hospitals in New Zealand and Australia. Mean PaO2 was significantly different between groups during CPB. There was no difference in the development of AKI (intervention arm 72.0% vs. usual care 66.2%; difference, -5.8% [95% CI, -16.1 to 4.7%]; P = 0.28), other markers of organ damage, or intensive care unit and hospital length of stay.
  
  
  
  Avoiding modest hyperoxemia during CPB failed to demonstrate any difference in AKI, markers of organ damage, or length of stay.
authors.affiliation: From the Cardiothoracic and Vascular Intensive Care Unit, Auckland City Hospital, Auckland, New Zealand (S.P.M., R.L.P.); Medical Research Institute of New Zealand, Wellington, New Zealand (S.P.M., R.L.P.); ANZIC-Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia (S.P.M., R.L.P., M.B.); Royal Adelaide Hospital, Adelaide, South Australia (K.D.); Clinical Perfusion, Green Lane Cardiothoracic Surgical Unit, Auckland City Hospital, Auckland, New Zealand (T.W.); and Department of Anaesthesiology, University of Auckland, Auckland, New Zealand (T.W.)Auckland City Hospital, Auckland, New ZealandAuckland City Hospital, Auckland, New ZealandAuckland City Hospital, Auckland, New ZealandAuckland City Hospital, Auckland, New ZealandAuckland City Hospital, Auckland, New ZealandCalvary Wakefield Hospital, Adelaide, South Australia.
authors.forename: Shay P
authors.initials: SP
authors.lastname: McGuinness
authors.forename: Rachael L
authors.initials: RL
authors.lastname: Parke
authors.forename: Kate
authors.initials: K
authors.lastname: Drummond
authors.forename: Tim
authors.initials: T
authors.lastname: Willcox
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.forename: Cornelius
authors.initials: C
authors.lastname: Kruger
authors.forename: Megan
authors.initials: M
authors.lastname: Baker
authors.forename: Keri-Anne
authors.initials: KA
authors.lastname: Cowdrey
authors.forename: Eileen
authors.initials: E
authors.lastname: Gilder
authors.forename: Lianne
authors.initials: L
authors.lastname: McCarthy
authors.forename: Thomas
authors.initials: T
authors.lastname: Painter
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D018496:Hyperoxia / Q000097:blood / Q000517:prevention & control*; D015994:Incidence; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000097:blood / Q000517:prevention & control; D009520:New Zealand / Q000453:epidemiology; D018384:Oxidative Stress; D011183:Postoperative Complications / Q000097:blood / Q000517:prevention & control*; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers