The risk

Think: What risk factors for the development of delirium does Mr. Williams currently have?

Delirium: Risk factors

Delirium can arise from a variety of factors (multi-factorial)(25) and as the definition states; "it is an acute disorder which is largely reversible"(3). Therefore, once delirium is recognised, prompt action must be taken to manage the disorder. Delirium should always be suspected when there is an acute change in a person's behaviour, cognition, or function especially in elderly patients, patients with dementia or depressed patients. To diagnose delirium a clinical assessment is required. A simple cognitive assessment and a delirium detection tool called the Confusion Assessment Method (CAM) are fundamental in detecting delirium(26).

There is a known association between two types of risk factors: 1) predisposing (factors already present such as old age) and 2) precipitating factors (noxious insults or hospital related factors such as infection or surgery) in the development of delirium(25). An older hospitalised person who has multiple predisposing factors would only require a slight insult by a precipitating factor, to develop delirium and conversely an older hospitalised person who has minimal risk factors would require a larger number of precipitating factors (noxious insults) before they develop delirium.

major insult (e.g serious infection, general anaesthetic, major surgery) is usually required to trigger delirium if the person was previously fit.

minor insult (e.g a dose of sleeping medication) can result in delirium if many underlying risk factors.

An understanding of these risk factors will increase your ability to recognise people at risk of delirium and confidently commence preventative interventions to decrease the persons risk of developing delirium. Interestingly these preventative interventions are the same as the nursing management strategies.

Summary of common Delirium risk factors - hospitalised person (1, 25, 27)
Aged 70 years or older* Hypoxia
Poor eyesight* or hearing impairment Infections
Pre-existing cognitive impairment (eg dementia)* Dehydration
Severe medical illness* Electrolyte disturbances
Medication or changes in medication* Constipation
Male gender Sleep deprivation
Previous history of delirium Immobility
Environmental Alcohol related health concerns
Surgical procedures Exposure to benzodiazepines
Use of physical restraints including IDCs Pre-operative use of narcotics or inadequate pain relief

* most commonly identified risk factors

NB: Often there are more than one factors present...

However, medications may be the sole precipitant in 12 - 39% of cases of delirium. The most common drugs associated with the precipitation of delirium are anticholinergic drugs, opiates and psychotropic drugs. These are not the only group of drugs and the below mnemonic provides some indication of the variety of drugs which may precipitate a delirium.

Drugs which may precipitate a delirium (28)
Antiparkisonian Cardiac (antiarrhythmics)
Insomnia medications Muscule relaxants
Corticosteroids H2 Blockers (cimetidine)
Narcotics Seizure medications
Urologic (antispasmotics) Anticholinergics
Theophylline NSAIDs
Emesis (antiemetics) Geropsychotropic