Anaesthesia in patients with dementia

The next couple of decades will be characterized by an increase in life expectancy, leading to an older population. As the incidence of Alzheimer's dementia and vascular dementia is rising with age, the future anaesthesiologist will be increasingly confronted with perioperative care of patients with impaired cognitive function. This paper tries to highlight some topics specifically related to demented patients.

Psychometric testing and behaviour vary according to the type of dementia. Neuroanatomical and biochemical correlates for different types of dementia are more precise and better documented. Evidence exists that cognition may be impaired for weeks after anaesthesia, but the mental capacities of those who have undergone surgery are comparable to those of age controls in the long term. Most research efforts are focused on improving the daily functioning of people with cognitive impairment. Several new anticholinesterases are being evaluated. It is advantageous to keep cognition optimal throughout the perioperative period. Neuroleptics may be badly tolerated and, most importantly, pain pathways may be differentially affected in dementia.

Anaesthesia in the demented patient may be complicated by a number of potential problems, including the comorbid pathology, the concomitant anticholinesterase activity, the need for normoventilation, monitoring of anaesthesia depth and the evaluation of postoperative pain. Anaesthesia in variant Creutzfeldt-Jakob disease is aimed at preventing the spread of the causing prion. There is a broad consensus that early return to the preoperative level of cognition is to be pursued, with the help of short-acting drugs and loco-regional anaesthesia.