Postoperative delirium: A tragedy for elderly cancer patients

Table 2 Factors associated with the risk of postoperative delirium[4]

Predisposing factors	Precipitating factors
Advanced age	Preoperative preparation: (1) Long-duration of fluid fasting; and (2) Preoperative pain
Lower educational level	Perioperative medication: (1) Anticholinergic drugs; (2) Benzodiazepines; (3) Opioid use; and (4) Use of pethidine
Functional status: (1) Cognitive impairment; (2) Hearing impairment; and (3) Frailty	Intraoperative factors/management: (1) Deep anesthesia; (2) Intraoperative blood loss/ blood transfusion; (3) Cerebral oxygen desaturation; (4) Hypotension; and (5) Hypothermia
Comorbidities: (1) Depression; (2) Psychiatric illness; (3) Cerebrovascular disease; (4) Parkinsonism; (5) Heart failure; (6) Hypertension; (7) Mitral valve disease; (8) Diabetes; (9) Obstructive sleep; (10) Pulmonary disease; (11) Kidney disease; and (12) Number of medications	Surgical management: (1) Abdominal/orthopedic surgery; (2) Higher surgical Apgar score; and (3) Long-duration surgery
Comorbidity scores: (1) Higher ASA grade; (2) NYHA functional class III/IV; (3) Higher EuroSCORE; and (4) Higher Charlson comorbidity index	Postoperative management: (1) Severe pain; (2) Long-duration mechanical ventilation; and (3) Prolonged stay in intensive care unit
Alcohol abuse
Nutritional status: (1) Malnutritional/low albumin; (2) Low preoperative hematocrit; and (3) Vitamin D deficiency

EuroSCORE: European system for cardiac operative risk evaluation; NYHA: New York Heart Association.