الفهرس 
Pathophysiology of postoperative deliriumOnly 14 pages are availabe for public view
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Abstract
More than 50 years ago, clinicians reported changes in mental functions after anesthesia and surgery especially in the elderly. As these changes increase in prevalence in subsequent years they have categorized into distinct syndrome of postoperative delirium and postoperative cognitive dysfunction.
The pathophysiology of POD is still obscure but the most accepted hypothesis is disturbance in wide variety of central neurotransmitter system especially lack of acetyl choline and relative increase in dopaminergic transmission.
POD represents one of the threatening complications after major surgery. It’s defined as a a change in mental status characterized by impairment of cognitive functions, disturbance of attention and reduced clarity of awareness of the environment.
POD has an acute onset, developing within hours to days and tends to fluctuate during the course of the day; it usually resolves within days.
In elderly hospitalized patients, the risk of developing delirium is predicted by interaction between predisposing factors present at the time of the hospitalization and precipitating factors that occurs during hospitalization.
The clinical diagnosis of POD is based on history from collaterals, physical examination which help to identify predisposing and precipitating factors.
Other neuorological tests have been used to diagnose delirium and to exclude other neuropsychiatric diseases which may mimic delirium especially in old age.
POCD describes deterioration in cognitive functions that’s temporarily associated with surgery and it should be distinguished from POD which has a transient and fluctuating course occurs shortly after surgery, whereas POCD is more persisting problem of change in cognitive performance as assessed by neuoropsychological test.
Cognitive dysfunction is common in adult patient of all ages, at hospital discharge after major surgery, but only the elderly (aged 60 or more) are at significant risk for long term cognitive disorders.
There are extensive studies investigating the proposition that regional anesthesia would be associated with less delirium and cognitive dysfunction than general anesthesia but the majority of these studies show no difference raising the possibility that cognitive decline occurs as a consequence of generalized illness rather than it being causatively related to surgery and or anesthesia.
Preventing delirium is the most effective strategy for reducing its frequency and complications. Successful preventive strategies include multicomponent approaches to reduce risk factors .
Once delirium occurs, the key steps in management are to address all evident causes, provide supportive care ,prevent complications and treat behavioral symptoms.