[Delirium following heart surgery with extracorporeal circulation: clinical aspects and observations in a specialized center]

Delirium following heart surgery with extra-corporeal circulation recently has been the subject of several studies that show a syndrome with variable diagnostic criteria and incidence which tend to confuse the entity. The diagnostic criteria proposed by the recent DSM-III of the American Psychiatric Association allow a better circumscription of the syndrome but exclude a group of patients manifesting visual hallucinations, sometimes paranoid features and cognitive functions that are less disturbed. Heller's and Kornfeld's less rigid criteria, on the other hand, have the disadvantage of including functional psychotic states that can arise after surgery without a true delirium with organic brain syndrome. We suggest the use of standard criteria that could include only delirium following cardiac surgery with E.C.C. and subdivision of the patients following the kind of surgery. In a retrospective study of the last four years at the Montreal Heart Institute, our clinical observations show an incidence of delirium after heart surgery with E.C.C. of 3%. a finding much lower than that reported in other centres which show an incidence between 13 and 67%. The more important factors found, were the kind of surgery (valve replacement more than coronary bypass), the age of the patients, and the degree of sickness after surgery during the stay in the intensive care unit. Those risk factors were also found in other recent studies. We describe the clinical syndrome and discuss its etiology in reviewing the more common risk factors before, during and after surgery. We underline the importance of the quality of the relationship with the patient before and after surgery in discussing prevention and treatment.