Dementia Coach

Acute Memory Loss and Delerium

Delirium is a sudden, fluctuating, and usually reversible cognitive disorder characterized by disorientation, the inability to pay attention, the inability to think clearly, and a change in the level of consciousness.

Delirium is an abnormal mental state, not a disease. Although the term has a specific medical definition, it is often used to describe any type of confusion.

Because delirium is a temporary condition, determining how many people have it is difficult. Delirium, which is usually a sign of a newly developed disorder, affects about one third of hospitalized people aged 70 or older.

Development or worsening of almost any disorder can cause delirium. Any person can become delirious when they are extremely ill or are taking drugs that affect brain function. However, delirium can result from less severe conditions in older people and in people whose brain has been affected by a stroke, dementia, or other disorders that cause nerve degeneration. In such people, delirium can result from a relatively minor illness, such as retention of urine or feces; sensory deprivation, such as that due to being socially isolated or not wearing glasses or hearing aids; or prolonged sleep deprivation. For example, the sensory and sleep deprivation that occurs in intensive care units (ICUs) may contribute to delirium. This disorder is sometimes called ICU psychosis.

Being in the hospital can also contribute to or trigger delirium. About 10 to 20% of older people develop delirium while they are in the hospital. Delirium is also very common after surgery, probably because of the stress of surgery, the anesthetics used during surgery, and the analgesics used after surgery. The most common reversible cause of delirium is drugs. (NIMH)

Delirium may occur in persons with a normal brain but is more common in those with underlying brain disease, such as dementia. It is more common in the elderly, probably due to changes in neurotransmitters, geriatric cerebral cell loss, and concomitant disease. Delirium may be due to primary brain diseases or diseases elsewhere in the body that affect the brain; causes are usually metabolic, toxic, structural, or infectious. Regardless of cause, the cerebral hemispheres or the arousal mechanisms of the thalamus and reticular activating system of the brain stem become physiologically impaired. Disruption of sleep and extreme stress superimposed on acute disease may worsen symptoms of delirium (as in intensive care psychosis).

Treatment

Symptoms are usually reversible when the underlying cause is identified quickly and managed properly, particularly if the cause is hypoglycemia, an infection, an iatrogenic factor, drug toxicity, or an electrolyte imbalance. However, recovery may be slow (days to even weeks or months), especially in the elderly.

All unnecessary drugs should be stopped. Identifiable disease should be treated, and fluids and nutrients should be given. A patient suspected of alcohol abuse or withdrawal should be given thiamine 100 mg IM daily for at least 5 days, to ensure absorption. During hospitalization, such patients should be monitored for signs of withdrawal, which can be manifested by autonomic disturbances and worsening confusion.

The environment should be as quiet and calm as possible, preferably with low lighting but not total darkness. Staff and family members should reassure the patient, reinforce orientation, and explain proceedings at every opportunity. Additional drugs should be avoided unless needed to reverse the underlying condition. However, sometimes agitation must be treated symptomatically, particularly when it threatens the well-being of the patient, a caregiver, or a staff member.

Few scientific data are available to guide the choice of drugs to treat delirium. Low doses of haloperidol (as little as 0.25 mg po, IM, or IV) or thioridazine (5 mg po) can help in managing the delirious patient. Larger doses (haloperidol 2 to 5 mg or thioridazine 10 to 20 mg) are sometimes needed. Newer drugs, such as risperidone, can be used instead of haloperidol for oral therapy but are not available IM or IV. Short- or intermediate-acting benzodiazepines (eg, alprazolam, triazolam) can control agitation over the short term; benzodiazepines may worsen confusion, but if required, the smallest effective dose should be used. All psychoactive drugs should be reduced and then eliminated as soon as possible so that recovery can be assessed. (Merk, 2^nd Edition)