Postoperative delirium: A tragedy for elderly cancer patients

Table 1 Definition of delirium by the Diagnostic and Statistical Manual of Mental Disorders, 5^th edition[1]

Diagnostic criteria
A disturbance in attention (i.e. reduced ability to direct, focus, sustain, and shift attention) and awareness (reduced orientation to the environment)
The disturbance develops over a short period of time (usually hours to a few days), represents a change from baseline attention and awareness, and tends to fluctuate in severity during the course of a day
An additional disturbance in cognition (e.g., memory deficit, disorientation, language, visuospatial ability, or perception)
The disturbances in criteria A and C are not better explained by another preexisting, established, or evolving neurocognitive disorder and do not occur in the context of a severely reduced level of arousal, such as coma
There is evidence from the history, physical examination, or laboratory findings that the disturbance is a direct physiological consequence of another medical condition, substance intoxication or withdrawal (i.e. due to a drug of abuse or to a medication), or exposure to a toxin, or is due to multiple etiologies