title: Carbon dioxide insufflation in open-chamber cardiac surgery: a double-blind, randomized clinical trial of neurocognitive effects.
abstract: OBJECTIVE
  The aims of this study were first to analyze neurocognitive outcomes of patients after open-chamber cardiac surgery to determine whether carbon dioxide pericardial insufflation reduces incidence of neurocognitive decline (primary end point) as measured 6 weeks postoperatively and second to assess the utility of carbon dioxide insufflation in cardiac chamber deairing as assessed by transesophageal echocardiography.
  
  
  METHODS
  A multicenter, prospective, double-blind, randomized, controlled trial compared neurocognitive outcomes in patients undergoing open-chamber (left-sided) cardiac surgery who were assigned carbon dioxide insufflation or placebo (control group) in addition to standardized mechanical deairing maneuvers.
  
  
  RESULTS
  One hundred twenty-five patients underwent surgery and were randomly allocated. Neurocognitive testing showed no clinically significant differences in z scores between preoperative and postoperative testing. Linear regression was used to identify factors associated with neurocognitive decline. Factors most strongly associated with neurocognitive decline were hypercholesterolemia, aortic atheroma grade, and coronary artery disease. There was significantly more intracardiac gas noted on intraoperative transesophageal echocardiography in all cardiac chambers (left atrium, left ventricle, and aorta) at all measured times (after crossclamp removal, during weaning from cardiopulmonary bypass, and at declaration of adequate deairing by the anesthetist) in the control group than in the carbon dioxide group (P < .04). Deairing time was also significantly longer in the control group (12 minutes [interquartile range, 9-18] versus 9 minutes [interquartile range, 7-14 minutes]; P = .002).
  
  
  CONCLUSIONS
  Carbon dioxide pericardial insufflation in open-chamber cardiac surgery does not affect postoperative neurocognitive decline. The most important factor is atheromatous vascular disease.
authors.affiliation: Department of Cardiothoracic Surgery, The Alfred Hospital, Melbourne, Australia.
authors.forename: Krish
authors.initials: K
authors.lastname: Chaudhuri
authors.forename: Elsdon
authors.initials: E
authors.lastname: Storey
authors.forename: Geraldine A
authors.initials: GA
authors.lastname: Lee
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.forename: Justin
authors.initials: J
authors.lastname: Chan
authors.forename: Franklin L
authors.initials: FL
authors.lastname: Rosenfeldt
authors.forename: Adrian
authors.initials: A
authors.lastname: Pick
authors.forename: Justin
authors.initials: J
authors.lastname: Negri
authors.forename: Julian
authors.initials: J
authors.lastname: Gooi
authors.forename: Adam
authors.initials: A
authors.lastname: Zimmet
authors.forename: Donald
authors.initials: D
authors.lastname: Esmore
authors.forename: Chris
authors.initials: C
authors.lastname: Merry
authors.forename: Michael
authors.initials: M
authors.lastname: Rowland
authors.forename: Enjarn
authors.initials: E
authors.lastname: Lin
authors.forename: Silvana F
authors.initials: SF
authors.lastname: Marasco
mesh_terms: D000368:Aged; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000009:adverse effects; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D016009:Chi-Square Distribution; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control* / Q000523:psychology; D004311:Double-Blind Method; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D007327:Insufflation / Q000009:adverse effects / Q000379:methods*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009422:Nervous System Diseases / Q000209:etiology / Q000517:prevention & control* / Q000523:psychology; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014739:Victoria
chemical_list: D002245:Carbon Dioxide