Postoperative psychosis after heart surgery.

One hundred heart surgery patients were followed throughout their postoperative periods to assess the incidence and etiology of postcardiotomy delirium. Factors evaluated were: age, sex, history of previous psychiatric illness, history of cerebrovascular disease, cardiac diagnosis and operation, time of anesthesia, time of bypass, time spent in the intensive-care unit, and amount of sleep during the postoperative period. Six patients developed delirium, five of whom had a lucid postoperative interval; four patients had perceptual disturbances only, without loss of contact with reality; three had neurological symptoms with mild confusion; 87 kept a clear mental state. The following factors tended to be related to the occurrence of delirium and perceptual disturbances: history of preoperative psychiatric illness, advanced age, severity of preoperative and postoperative illness, and time spent in the intensive-care unit. Sleep deprivation consistently preceded onset of these symptoms with one exception. Operative factors did not seem to be of major importance. While postoperative delirium probably has multidetermined causes, the author believes that sleep deprivation superimposed on the other contributory condition is a common precipitating factor. Suggestions about the prevention and treatment of delirium are made.