Preconditioning With Repeated Hyperbaric Oxygen Induces Myocardial and Cerebral Protection in Patients Undergoing Coronary Artery Bypass Graft Surgery: A Prospective, Randomized, Controlled Clinical Trial

ObjectivesTo evaluate the cerebral and myocardial protective effects of hyperbaric oxygen preconditioning in both on-pump and off-pump coronary artery bypass graft surgery.DesignA prospective, randomized, single-blinded study including patients scheduled for elective on-pump or off-pump surgery between December 2007 and February 2009.SettingA tertiary care university teaching hospital.ParticipantsForty-nine elective on-pump or off-pump coronary artery bypass graft surgery patients.InterventionsPatients were randomized to either the control (15 patients with on-pump procedure and 10 patients with off-pump procedure, respectively) or hyperbaric oxygen (HBO; 14 patients with on-pump procedure and 10 patients with off-pump procedure, respectively) groups. Patients in the HBO groups underwent preconditioning for 5 days before surgery.Measurements and Main ResultsOn-pump coronary artery bypass graft surgery patients preconditioned with HBO had significant decreases in S100B protein, neuron-specific enolase, and troponin I perioperative serum levels compared with the on-pump control group. Postsurgically, patients in the on-pump HBO group had a reduced length of stay in the intensive care unit and a decreased use of inotropic drugs. Serum catalase activity 24 hours postoperatively was significantly increased compared with the on-pump control group. In the off-pump groups, there was no difference in any of the same parameters.ConclusionsPreconditioning with HBO resulted in both cerebral and cardiac protective effects as determined by biochemical markers of neuronal and myocardial injury and clinical outcomes in patients undergoing on-pump coronary artery bypass graft surgery. No protective effects were noted in off-pump coronary artery bypass graft surgery.