Coronary artery bypass grafting (CABG) is a worldwide used myocardial revascularization procedure, which despite the modern advantages still has a spectrum of complications, especially in old age population.

The relatively old age of the patients who undergo CABG and their widespread atherosclerotic disease are possible reasons for vascular sequels leading to neurological and psychic dysfunctions. Delirium in the elderly after CABG surgery is common, according to some authors and our investigation, is detected in about 20- 34% causes and is often under-diagnosed. Its occurrence may be predisposed by a history a stroke and precipitated by a longer duration of cardiopulmonary bypass.

Increasing age, blood urea level, cardio-thoracic index, hypertension, smoking habits, blood replacement during bypass, atrial fibrillation(AF), pneumonia and blood balance in the post-operative period are the main risk factors for delirium. No specific factor associated with the CABG (eg. perfusion pressure, number of grafts) is correlated with increased risk for delirium post-operatively.

The number of studies (and our observations) have shown that patients in whom delirium develop have more complication rates, longer hospital stays, an increased rates of transfer to rehabilitation or long –term care facilties.

Finally, the identification and control of the risk factors for delirium should bring a decrease in delirium morbidity and mortality.