Patient selection: patient >= 50 years undergoing major surgery
Preoperative risk factors:
(1) increasing age (postoperative delirium in 20% for 50-59 years to 90% if >= 80 years)
(2) serum albumin < 3.4 g/dL
(3) anemia
(4) functional disability
(5) pre-existing dementia or cognitive impairment
(6) comorbidity (using the Charlson index)
(7) history of alcohol abuse
Intraoperative risk factors:
(1) intraoperative hypotension with systolic blood pressure < 90 mm Hg
(2) blood transfusion (>= 3 units)
Limitations: Postoperative risk factors were not reported. These may include:
(1) drug or alcohol withdrawal
(2) opiate therapy
The occurrence of postoperative delirium was associated with worse outcomes including length of hospital stay, postdischarge institutionalization and mortality at 6 months.
