title: Xenon for the prevention of postoperative delirium in cardiac surgery: study protocol for a randomized controlled clinical trial.
abstract: BACKGROUND
  Postoperative delirium (POD) is a manifestation of acute postoperative brain dysfunction that is frequently observed after cardiac surgery. POD is associated with short-term complications such as an increase in mortality, morbidity, costs and length of stay, but can also have long-term sequelae, including persistent cognitive deficits, loss of independence, and increased mortality for up to 2 years. The noble gas xenon has been demonstrated in various models of neuronal injury to exhibit remarkable neuroprotective properties. We therefore hypothesize that xenon anesthesia reduces the incidence of POD in elderly patients undergoing cardiac surgery with the use of cardiopulmonary bypass.
  
  
  METHODS
  One hundred and ninety patients, older than 65 years, and scheduled for elective cardiac surgery, will be enrolled in this prospective, randomized, controlled trial. Patients will be randomized to receive general anesthesia with either xenon or sevoflurane. Primary outcome parameter will be the incidence of POD in the first 5 postoperative days. The occurrence of POD will be assessed by trained research personnel, blinded to study group, with the validated 3-minute Diagnostic Confusion Assessment Method (3D-CAM) (on the intensive care unit in its version specifically adapted for the ICU), in addition to chart review and the results of delirium screening tools that will be performed by the bedside nurses). Secondary outcome parameters include duration and severity of POD, and postoperative cognitive function as assessed with the Mini-Mental State Examination.
  
  
  CONCLUSIONS
  Older patients undergoing cardiac surgery are at particular risk to develop POD. Xenon provides remarkable hemodynamic stability and has been suggested in preclinical studies to exhibit neuroprotective properties. The present trial will assess whether the promising profile of xenon can be translated into a better outcome in the geriatric population.
  
  
  BACKGROUND
  EudraCT Identifier: 2014-005370-11 (13 May 2015).
authors.affiliation: Department of Anesthesiology, KU Leuven - University of Leuven, University Hospitals of Leuven, Herestraat 49, B-3000, Leuven, Belgium. layth.altmimi@uzleuven.be.
authors.forename: Layth
authors.initials: L
authors.lastname: Al Tmimi
authors.affiliation: Department of Anesthesiology, KU Leuven - University of Leuven, University Hospitals of Leuven, Herestraat 49, B-3000, Leuven, Belgium. marc.vandevelde@uzleuven.be.|Department of Cardiovascular Sciences, KU Leuven - University of Leuven, B-3000, Leuven, Belgium. marc.vandevelde@uzleuven.be.
authors.forename: Marc
authors.initials: M
authors.lastname: Van de Velde
authors.affiliation: Department of Cardiovascular Sciences, KU Leuven - University of Leuven, B-3000, Leuven, Belgium. paul.herijgers@uzleuven.be.|Department of Cardiac Surgery, KU Leuven - University of Leuven, University Hospitals of Leuven, Herestraat 49, B-3000, Leuven, Belgium. paul.herijgers@uzleuven.be.
authors.forename: Paul
authors.initials: P
authors.lastname: Herijgers
authors.affiliation: Department of Cardiovascular Sciences, KU Leuven - University of Leuven, B-3000, Leuven, Belgium. bart.meyns@uzleuven.be.|Department of Cardiac Surgery, KU Leuven - University of Leuven, University Hospitals of Leuven, Herestraat 49, B-3000, Leuven, Belgium. bart.meyns@uzleuven.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Meyns
authors.affiliation: Department of Intensive Care Medicine, KU Leuven - University of Leuven, University Hospitals Leuven, Herestraat 49, B-3000, Leuven, Belgium. geert.meyfroidt@uzleuven.be.|Department of Intensive Care Medicine and Cellular and Molecular Medicine, KU Leuven - University of Leuven, Herestraat 49, B-3000, Leuven, Belgium. geert.meyfroidt@uzleuven.be.
authors.forename: Geert
authors.initials: G
authors.lastname: Meyfroidt
authors.affiliation: Department of Public Health and Primary Care, KU Leuven - University of Leuven, B-3000, Leuven, Belgium. Koen.Milisen@med.kuleuven.be.
authors.forename: Koen
authors.initials: K
authors.lastname: Milisen
authors.affiliation: I-Biostat, KU Leuven - University of Leuven, B-3000, Leuven, Belgium. steffen.fieuws@uzleuven.be.
authors.forename: Steffen
authors.initials: S
authors.lastname: Fieuws
authors.affiliation: Department of Anesthesiology, University Hospital of the RWTH Aachen, Aachen, Germany. mcoburn@ukaachen.de.
authors.forename: Mark
authors.initials: M
authors.lastname: Coburn
authors.affiliation: Laboratory Medicine, KU Leuven - University of Leuven, University Hospitals Leuven, Herestraat 49, B-3000, Leuven, Belgium. koen.poesen@uzleuven.be.|Department of Neurosciences, Laboratory for Molecular Neurobiomarker Research, KU Leuven - University of Leuven, Herestraat 49, B-3000, Leuven, Belgium. koen.poesen@uzleuven.be.
authors.forename: Koen
authors.initials: K
authors.lastname: Poesen
authors.affiliation: Department of Anesthesiology, KU Leuven - University of Leuven, University Hospitals of Leuven, Herestraat 49, B-3000, Leuven, Belgium. steffen.rex@uzleuven.be.|Department of Cardiovascular Sciences, KU Leuven - University of Leuven, B-3000, Leuven, Belgium. steffen.rex@uzleuven.be.
authors.forename: Steffen
authors.initials: S
authors.lastname: Rex
mesh_terms: D000367:Age Factors; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000009:adverse effects; D001530:Belgium; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D057189:Checklist; D002985:Clinical Protocols; D003071:Cognition / Q000187:drug effects; D003693:Delirium / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control* / Q000523:psychology; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D012107:Research Design; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D014978:Xenon / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D018685:Anesthetics, Inhalation; D018696:Neuroprotective Agents; D014978:Xenon