Slow down, and start with your ABCDs.
When you get to D, it’s time to start thinking also diagnosis and its differential. The cause of the deterioration will fall under a syndrome classification as either a delirium (organic acute, decompensated), dementia (organic, chronic) or depression (acute or chronic, functional). The crucial point is to get a good idea of the time-course of events, how the situation has evolved over minutes, hours, and perhaps even days.
Delirium
A delirious patient becomes inattentive, showing an inability to focus that has developed only of late and often with a diurnal fluctuation in severity. This is a crucial finding in a delirium, the fluctuation from moment to moment, hour to hour, throughout the day.¹ There will always be an associated physiological derangement to explain the sudden global deterioration in cognition or consciousness, be it in metabolic profile or a history of substance use or withdrawal.
The bad news is that a delirium suggests a new, potentially life-threatening complication. The good news is that most deliriums are reversible, related to any of the following (listed here in the order they might present themselves during either your primary or secondary survey):
- hypoxia or hypercarbia
- shock
- decompensated heart failure
- dehydration
- acute blood loss
- sepsis
- stroke (small cortical)
- metabolic disorders
- electrolyte abnormalities
- acid-base disturbance
- azotemia
- hypo- or hyperglycaemia
- pharmaceutical
- medications
- intoxication
- other
- faecal impaction
- urinary retention¹
Nursing home residency or hospitalisation, especially intensive care or after surgery, increases the risk of delirium, as does a history of dementia, visual or hearing impairment, and multiple comorbidities and poly-pharmacy. Five (5) independent risk factors for delirium have been confirmed:
- use of physical restraints
- malnutrition
- bladder catheter
- any iatrogenic event
- taking three or more medications²
Because of a 25% associated mortality (higher in hospitalised patients) and potential reversibility, always consider a delirium first in any elderly patient exhibiting cognitive impairment or behavioural change, especially in the acute setting. There will be disorientation with a clouding of consciousness, a strikingly short attention span, a disturbed sleep-wake cycle, and marked psychomotor change.
Dementia
Here the decline in intellectual function is more gradual, rendering the person deficient in performance of activities of daily living (ADLs) based upon a gradual decline in intellectual functioning over months to years. The key finding in a dementia is the impairment of memory, usually associated with either aphasia, apraxia, or agnosia.¹ The history is crucial in establishing the pre-morbid state and recency of mental decline. The causes include:
- Alzheimer’s disease: beta amyloid deposition
- Vascular dementia
- CNS trauma
- Parkinson disease (and other Lewy-body dementias)
- Pick’s disease
- Acquired Immune Deficiency Syndrome
- Creutzfeldt-Jakob disease
- Huntington’s disease¹
But even the odd dementia will potentially be reversible — “thyroid dysfunction, vitamin deficiencies and normal-pressure hydrocephalus”.¹
Depression
Deterioration in function in a depression is gradual, usually over at least two weeks, and involves a reduction in mood, loss of interest, change in appetite with weight loss (or gain), insomnia or hypersomnia, psychomotor agitation or retardation, fatigueability, guilt, poor concentration, perhaps even thoughts of self harm.
Conclusion
The examination of a confused patient should focus on the cardiovascular and neurological systems as well as a psychiatric evaluation, including a mini-mental state examination. It’s wise to perform a medication review at least in your head, if not more formally, for all confused patients, looking particularly for anticholinergic drugs, benzodiazepines, and narcotic analgesics. Onset, attention, and fluctuation are three factors that help you differentiate a delirium from dementia.
Medications associated with Delirium
- benzodiazepines
- antiparkinsonian agents
- antidepressants
- antipsychotics
- anticonvulsants
- lithium
- antiarrhythmics
- antihypertensives
- H2 blockers
- corticosteroids
- opioids
- NSAIDs
- pseudoephedrine
- St. John’s Wort
- antihistamines
- antispasmodics
Patient Education
Francis, Joseph et al. (2020) Patient education: Delirium (Beyond the Basics). UpToDate. Available at https://www.uptodate.com/contents/delirium-beyond-the-basics. Accessed 27 Mar 2020.
References
- Espino, D. V. et al. (1998) Diagnostic approach to the confused elderly patient. American Family Physician. 57 (6), 1358–1366. [online]. Available from: http://search.proquest.com/docview/79771523/.
- Mayo Clinic Staff (2018) Delirium. Mayo Clinic (online). Available at https://www.mayoclinic.org/diseases-conditions/delirium/symptoms-causes/syc-20371386. Accessed 27 Mar 2020.
- Kannayiram A. et al. (2019) Delirium Clinical Presentation. Medscape (online). Available at https://emedicine.medscape.com/article/288890-clinical#b5. Accessed 27 Mar 2020.
Further Reading
- Diwell, R. A. (2018) Key components of the delirium syndrome and mortality: greater impact of acute change and disorganised thinking in a prospective cohort study. BMC Geriatrics, 18(1), 24. https://doi.org/10.1186/s12877-018-0719-1.
- Gupta S and Gupta A. Confusion in the older patient: a diagnostic approach. GM Journal. Available at https://www.gmjournal.co.uk/confusion-in-the-older-patient-a-diagnostic-approach.
- Kalish, V. B. et al. (2014) Delirium in older persons: evaluation and management. American Family Physician. 90 (3), 150–158. [online]. Available from: http://search.proquest.com/docview/1551021974/.
- Johnson, M. H. ( ) Assessing Confused Patients.
- Pham, C. B. et al. (2007) Minimizing adverse drug events in older patients. American Family Physician. 76 (12), 1837–1844. [online]. Available from: http://search.proquest.com/docview/70059719/.
Downloads
coped-guide [Queensland Health]
Predicting Delirium in Hospitalized Older Patients [American Family Physician]
Appropriate Use of Psychotropic Drugs in Nursing Homes [American Family Physician]
