USMLE – Acute Confusional State
This is also known as delirium and is seen much more commonly than dementia. Unlike dementia, there is global impairment of mental function associated with disturbance of arousal. This Nobis canada usually takes the form of drowsiness with disorientation, perceptual disturbances and muddled thinking. Patients typically fluctuate, confusion being worse at night and there may be associated emotional disturbance (e.g. anxiety, irritability or depression) or psychomotor changes (e.g. agitation, restlessness or retardation).
Acute confusional states may be the result of acute decompensation of any of the causes of dementia. However, there are many other possible causes of acute confusion.
The diagnosis of an acute confusional state involves careful history-taking. Patients are usually disorientated, often in both time and place and therefore their account may not be helpful. As with dementia, it is vital to lake a history from a witness (either a relative or a nurse). Examination may yield other clues to the cause (e.g. pyrexia, or focal chest or neurological signs). It is important to exclude a fluent aphasia, since patients with this speech disorder often appear confused despite having a focal cortical lesion. Often, however, the cause is not immediately obvious, and a wide screen of tests must be performed.
The management of acute confusional states involves identifying the cause and correcting it if possible. Confused patients should be nursed in a well-lit room. During the period of confusion, drugs are best avoided, as they may serve simply to heighten the confusion, though occasionally sedative drugs such as chlorpromazine (25-100 mg 8-hourly) or haloperidol (2.5-10 mg 8 hourly) may be required. In delirium tremens (alcohol withdrawal), the treatment is a tapered course of chlormethiazole or chlordiazepoxide to accompany high-dose intravenous thiamin.