attentional deficits, and disorganization of behavior. It typically involves other cognitive deficits, changes in arousal (hyperactive, hypoactive, or mixed), perceptual deficits, altered sleep-wake cycle, and psychotic features such as hallucinations and delusions.
Delirium itself is not a disease, but rather a set of symptoms.
Symptoms include the following: Fluid and nutrition should be given carefully because the patient may be unwilling or physically unable to maintain a balanced intake.
Delirium may be difficult to diagnose without the proper establishment of a person's usual mental function.The elderly population is increasing at an unprecedented rate and, as a result, the number of surgical procedures in the elderly will increase dramatically in the future.The incidence of postoperative delirium will likely also increase unless strategies for preventing it can be developed.DELIRIUM is a common and serious postoperative complication occurring in 5–15% of elderly patients after general anesthesia1 and up to 64% of patients undergoing spinal anesthesia for hip fracture surgery.2 Postoperative delirium is independently associated with increased mortality, duration of hospital stay, functional disability, placement in long-term care institutions, and hospitalization costs.3,4 It is estimated that delirium occurs in at least 20% of the 12.5 million individuals aged 65 yr or older who are hospitalized each year and increases the cost of hospitalization by ,500 for each patient who develops this complication.5,6 A study evaluating the total 1-yr healthcare costs for elderly individuals who developed delirium while hospitalized estimated that the national burden of delirium on the healthcare system may be as high as 2 billion each year.7 The etiology of postoperative delirium has not been clearly elucidated because it is a heterogeneous and multifactorial disorder involving a complex interrelation between a vulnerable patient with preoperative risk factors who is exposed to numerous precipitating factors in the perioperative period.5,8 A recent systematic review8 of the literature found that, although various studies have identified multiple risk factors of delirium, two previously validated prediction models9,10 remain helpful in identifying at-risk patients.Preexisting cognitive impairment (as measured with global mental status examinations) is the only item common to both of these predictive models and has been frequently cited as an important risk factor in numerous other studies.8 The systemic review8 also identified depression as a significant risk factor, and more recent studies in medical11 and surgical12,13 patients support the view that depressed elderly patients are at high risk for developing delirium.