Preconditioning with repeated hyperbaric oxygen induces myocardial and cerebral protection in patients undergoing coronary artery bypass graft surgery: a prospective, randomized, controlled clinical trial.

OBJECTIVES To evaluate the cerebral and myocardial protective effects of hyperbaric oxygen preconditioning in both on-pump and off-pump coronary artery bypass graft surgery. DESIGN A prospective, randomized, single-blinded study including patients scheduled for elective on-pump or off-pump surgery between December 2007 and February 2009. SETTING A tertiary care university teaching hospital. PARTICIPANTS Forty-nine elective on-pump or off-pump coronary artery bypass graft surgery patients. INTERVENTIONS Patients 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 RESULTS On-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. CONCLUSIONS Preconditioning 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.