 60 patients scheduled to undergo coronary revascularization were recruited for this trial. Exclusion criteria included Emergency operation, age older than 80 years, learning difficulty, previous cerebrovascular disease, visual or hearing impairment, history of pneumothorax, Claustrophobia, middle ear disease, EF 35. Patients were randomized either to the control group or hyperbaric oxygen group. The laboratory analysis of markers included S100B, NSE and troponin I. The assessment of cognitive dysfunction was performed 5 days before surgery and 7 days after surgery and haemodynamic measurements, length of stay in ICU, length of stay in hospital post-operation were recorded. 