Regional anesthesia for acute pain management in elderly patients

Table 4 Types of cognitive dysfunction

MCI (4 subtypes associated with causes of dementia)	Concept to describe transitional level of neurocognitive impairment
	MCI is a predictor of future dementia
	Diagnosis by neuropsychological testing and clinical observation
	Divided into 4 subtypes (based on presence of: (1) memory impairment plus; (2) number of other cognitive domains affected)
	Preoperative MCI may result in postoperative delirium
Delirium	Fluctuating consciousness, develops over hour to days
	Altered perception and cognition (not associated with dementia)
	In hospital predictors of delirium include:
	Bladder catheters
	↓ Functional status
	Male gender
	Malnutrition
	Infection
	Depression
	3 or more medications
	H2 antagonists
	Age
	Opioids
	Iatrogenic events
	Benzodiazepines
	Alcohol + drug abuse
POD[74]	Develops on postoperative day 1-3, can be sustained > 1 wk
	Age associated central cholinergic deficiency as a positive predictor
	Two types of postoperative delirium:
	Hypoactive form (more common and more commonly overlooked)
	Hyperactive type
	Perioperative use of benzodiazepines are associated with POD
	Postoperative in-dwelling perineural catheters reduce incidence of POD
Emergence Delirium	Present upon regaining consciousness following general anesthesia
	Predicts postoperative delirium
POCD	Condition in which patients have difficulty in performing cognitive tasks following surgery that they could perform prior to surgery
	Occurs frequently in and following: carotid endarterectomy, hip fracture repair surgery and cardiac surgery patients (most frequent)
	ISPOCD: developed criteria of POCD based on pre- and post-operative neuropsychological testing scores
	Predictors of POCD 1 wk postoperatively include:
	Duration of anesthesisa
	Age (predictor of POCD at 3 mo)
	Postoperative infection
	Low level of patient education
	Pulmonary complications
	Need for a second operation
Dementia Alzheimer’s disease (most common form), vascular dementias, frontal lobe, reversible, senile, Lewy body, and Parkinson-associated	Apathy and personality changes occur early
	Behavioral changes appear as the condition progresses
	Psychotic symptoms are late signs (typically difficult to control)
	Multiple cognitive deficits
	Clinical findings are associated with:
	Problems with social activities
	Decline from a previous status
	Problems of occupational activities
	Gradual and progressive loss of mental abilities
	Dementia often results in postoperative delirium

POCD: Postoperative cognitive dysfunction; ISPOCD: International study of postoperative cognitive dysfunction; MCI: Mild cognitive impairment; POD: Postoperative delirium.