Delirium Following Cardiac Surgery: Incidence and Risk Factors
Abstract
The purpose of this retrospective study was to
determine the incidence of and risk factors for delirium in
patients undergoing cardiac surgery. In addition, the influence of
different post-surgical intensive care unit (leU) environments on
delirium incidence was also studied. A detailed clinical report
form was created to collect pertinent data in order to determine
the effect of pre-operative, intraoperative and postoperative
variables on delirium. Our study identified several risk factors for an
increased incidence of delirium: hypertension, preoperative statin use,
coronary artery bypass graft (CABO) surgery, aortic valve surgery,
advanced age, prolonged bypass time and lowest serum sodium value
during surgery. Extubation in the OR was associated with a lower
incidence of delirium. In our comparison of the different ICU
environments, in the first cohort (environment #1), 19.2% of patients
experienced at least one episode of delirium. In the second cohort
(environment #2; enhanced by privacy, reduced noise, and natural
light), the incidence was reduced to I 1.1 % (p = 0.0582). As the two
cohorts had otherwise similar demographics and other perioperative
characteristics, it is likely that the reduced incidence of delirium was
attributable to the enhanced ICU environment.