Delirium in the Elderly

Delirium is an acute disorder that affects cognition and attention. Delirium or confusion is more frequent in advanced age. The incidence also increases with high number of medications, frailty, comobirdity and previous cognitive impairment. 

Elderly patients after admission to a hospital often first show mental signs and symptoms, then show behavioural disturbances (Saravay et al. 2004). Thus if early mental signs and symptoms are identified and acted on, behavioural disturbances and subsequent extended length of hospital stay may be prevented. For cognitive testing many screening instruments are available. The most widely used is probably Mini Mental State Examination (MMSE). 

There are substantial costs due to delirium. The increased length of hospital care is obvious but also after hospital discharge the costs increase due to increased need for institutionalisation, community health care and rehabilitation. 

Delirium often has a multifactorial cause (Box 6.1). Elderly patients with severe illness or who are already cognitively impaired are vulnerable to delirium. Malnutrition or dehydration may further enhance the risk. The most common causes for delirium are drugs and diseases. Frail elderly who are vulnerable to delirium may be pushed into delirium by one dose of an inappropriate drug or by e.g. urinary retention whereas younger individuals are far more resistant. 

Multiple medications Cognitive impairment Dehydration or malnutrition Severe illness Vision impairment Functional impairment Sleep deprivation 

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The use of benzodiazepines should be avoided. There are other safer pharmacological alternatives. Benzodiazepine withdrawal may play a role in the occurrence of delirium in the elderly. Other withdrawal symptoms include tremor, agitation, insomnia and seizures (Turnheim 2003). Thus, when there is long-term use of benzodiazepines abrupt discontinuation might be difficult. Discontinuation should however not be withheld but done slowly and step-wise. If benzodiazepines are used in the elderly, short-acting benzodiazepines such as oxazepam are preferred, because they do not accumulate in the elderly to the same extent (Kompoliti and Goetz 1998). If short-acting benzodiazepines are used they should be prescribed with caution, at low doses, and for short periods. As with all pharmacotherapy the effects should be evaluated. Benzodiazepines are sometimes used as a behavioural control. One should always ask if this use is for the benefit of staff or the benefit of the patient. The presence of staff may be sufficient for behavioural control. 

Alagiakrishnan K and Wiens CA (2004) An approach to drug induced delirium in the elderly. Postgrad Med J 80(945) 388-393... 

Cone LA, Padilla L, Potts BE. Delirium in the elderly resulting from azithromycin therapy. Surg Neurol 2003 59 509-11. 

Avoid amitriptyline (number one cause of anticholinergic delirium in the elderly). 

Tune LE, BylsmaFW (1991) Benzodiazepine-induced and anticholinergic-induced delirium in the elderly. Int Psychogeriatr 3 397-408... 

Observational Studies Practice guidelines recommend the use of haloperidol for the treatment of delirium in the elderly however, a chart review foxmd that higher doses were frequently used with greater risk of adverse effects such as sedation [149 ]. 

Delirium is characterized by a disturbance of consciousness and a change in cognition that develops over a short period of time, usually hours or days. The course can fluctuate over the course of the day, usually worsening in the evening. Underlying medical problems such as urinary tract infections in the elderly, substance abuse, or withdrawal symptoms in adults may precipitate delirium.1... 

These differences may become particularly germane if co-prescribing with some antipsychotics is undertaken. For example, in certain individuals, combinations of clozapine with benzodiazepines may lead to unexpected adverse events, including delirium and augmented respiratory depression (Jackson, Markowitz Brewer-ton, 1995 Grohmann et al, 1989). Presumably if there are additive or synergistic effects of ethnicity on clearance of one or both substances, adverse events may be enhanced. Similar interactions are theoretically possible with olanzapine, as adverse interactions have been described between olanzapine and benzodiazepines, at least in the elderly (Kryzhanovskaya etal, 2006). 

Anti muscarinics Hyperthermia due to blockage of sweating mechanisms, decreased salivation and lacrimation, acute-angle-closure glaucoma in the elderly, urinary retention, constipation, blurred vision, delirium, and hallucinations... 

There is an increased risk of sedation and delirium with increased age. There is also an increased risk of antidopaminergic effects such as parkinsonism due to antipsychotic drugs. Many other drugs that pass the blood-brain barrier may cause adverse effects in the elderly. The response of opioids may be increased in the elderly, resulting in oversedation (Turnheim 1998). 

Delirium is a severe condition that in the elderly often is caused by drugs... 

Henderson AS, Korten AE, Levings C et al. (1998) Psychotic symptoms in the elderly a prospective study in a population sample. Int J Geriatr Psychiatry 13 (7) 484-492 Inouye SK and Charpentier PA (1996) Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability. JAMA 275 (11) 852-857... 

Adverse effects of the TCAs on the brain include confusion, impaired memory and cognition and occasionally delirium some of these effects have been reported to occur in up to 30% of patients over the age of 50. These effects may occasionally be confused with a recurrence of the s)nnptoms of depression and are probably due to the central antimuscarinic activity of these drugs. Tremor also occurs frequently, particularly in the elderly, and may be controlled by the concurrent administration of propranolol. Neuroleptics are normally not recommended to be used in combination with TCAs as they are liable to accentuate the side effects of the latter drugs. The risk of seizures, and the switch from depression to mania in bipolar patients, has also been reported following TCA administration. 

Urticaria, hallucinations, and confusion (including delirium, disorientation, confu-sional state, occurring predominantly in the elderly) have been reported. 

The histamine-2 receptor blockers (H-2 blockers) are used to treat hyperacidity in the stomach, and the most commonly used medications are available over the counter (without prescription). The first one was cimetidine (brand name Tagamet), which is a very common cause of delirium, confusion, psychosis, and aggression in the elderly—especially at night. The other H-2 blockers, such as ranitidine (brand name Zantac) and famotidine (brand name Pepcid), can also cause these symptoms, which are quite rare with these two drugs. Cimetidine should be avoided in the elderly and those with a serious illness. The H-2 blockers can also cause depression, mania, and nightmares. Therapists will see many patients who are taking H-2 blockers, and the patients may not... 

Delirium, toxic confusional state, metabolic encephalopathy or acute confusional state are terms that are used interchangeably and often loosely to describe a syndrome of acutely disordered cognition, sometimes associated with reduced level of consciousness and abnormal attention (see Table 32.1). The syndrome is very common, especially in the elderly and in patients with dementia, and presentations vary widely both in the speed of onset and severity (Siddiqi et al. 2006). The differential diagnosis is broad and includes almost any medical condition, but the commonest causes are sepsis, adverse drug reaction and metabolic derangement (Francis et al. 1990). 

A prospective study of delirium in hospitalized elderly. Journal of the American Medical Association 263 1097. 

In elderly patients, depression may mimic dementia, and in the elderly confused patient in hospital, it may be difficult to distinguish between dementia and delirium in which there is fluctuating confusion, poor attention and changes in arousal secondary to underlying physiological disturbance. Factors distinguishing between dementia and delirium are shown in Table 32.1. 

Neurotoxicity, including delirium and other mental status changes, may occur even at therapeutic doses in elderly and organically compromised patients Lower doses and lower plasma lithium levels (<0.6 mEg/L) are often adequate and advisable in the elderly... 

Psychotropic side effects that are more pronounced in the elderly are sedation, anticholinergic reactions, extrapyramidal symptoms, delirium, postural hypotension, cardiotoxicity, and cognitive impairments. Constipation is common and particularly... 

The deliberate or accidental ingestion of belladonna alkaloids is a major cause of toxicity in humans. The most dangerous and spectacular manifestation of poisoning arises from the intense excitation of the central nervous system (CNS). Infants and young children are especially susceptible to the toxic effects of atropinic drugs. In adults, delirium or toxic psychoses without undue peripheral manifestations have been reported after instillation of atropine eye drops. Transdermal preparation of scopolamine has been reported to cause toxic psychoses, especially in children and in the elderly. Serious intoxication may occur in children who ingest berries or seeds containing... 

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