A delirium is rarely the consequence of a single event. It arises from the interplay of two groups of factors:
- Predisposing factors: those that make the patient susceptible — advanced age, pre-existing cognitive impairment, impaired vision and hearing, polypharmacy, frailty, previous episodes of delirium.
- Triggering factors: those that bring the acute tipping point — operation, infection, pain, change of medication, dehydration, an unfamiliar environment.
The model is important to understand: the more susceptible the patient, the smaller the triggering stimulus has to be. A robust 75-year-old often survives a hip operation without delirium. A frail 88-year-old with beginning dementia and eight medications can already become delirious from a simple urinary tract infection — without an operation, without trauma, without a new medication.
This very insight is the starting point of all prevention: if the predisposing factors are unchanged, the management of the triggering factors is the decisive lever.
→ For a detailed account of delirium: Delirium in Older People.
The Hospital Elder Life Program (HELP), developed by Sharon Inouye at Yale University and first published in 1999, is the best-studied delirium prevention program in the world. It addresses six central risk factors with structured interventions:
1. Cognitive stimulation
- Structured, regular conversation with the patient
- Orientation aids: clock, calendar, personal photos, familiar objects
- Involvement of caregivers (relatives, volunteers)
- Activities that fit the previous life — reading the newspaper aloud, listening to music, conversations about biographical matters
2. Protect sleep
- Nightly routine measures (blood pressure, temperature) only when clinically necessary
- Reduce noise and light at night
- Non-drug aids to falling asleep (warm milk, tea, relaxation music)
- Avoidance of benzodiazepines and Z-substances as sleeping aids in the hospital
3. Early mobilization
- First mobilization if possible on the day of surgery or Day 1 — particularly important for the prevention of immobility in old age
- Daily getting up, walking, sitting even in severe illness
- Activating care — help toward self-help rather than complete takeover
- Avoidance of unnecessary restraints and lines that hinder mobility
4. Optimize vision
- Glasses at hand and cleaned
- Sufficient lighting, especially at night
- Large, easily legible orientation aids
5. Secure hearing
- Hearing aid at the bedside, switched on, with fresh batteries
- Speak clearly, calmly and at a medium volume
- Maintain eye contact, keep mouth movements visible
6. Fluid and nutrition management
- Monitor sufficient fluid intake — 1.5 to 2 liters per day, more in the case of fever or heat
- Make meals reachable, provide assistance if needed
- Protein-rich food to avoid malnutrition in old age
Scientific data: HELP reduces the incidence of delirium by 30 to 40 percent, shortens the length of stay and demonstrably improves the rate of return to one’s own home. International studies in 17 countries confirm its effectiveness.
Systematic medication review
In every older patient at admission: which medications promote delirium? Are there alternatives? The most important candidates for reduction:
- Benzodiazepines and Z-substances (lorazepam, diazepam, zolpidem, zopiclone)
- Strongly anticholinergic substances
- Tricyclic antidepressants
- High-dose opioids — better a lower-dosed multiple combination
- Certain antibiotics with a neuropsychiatric profile
→ How structured deprescribing works in practice: Reducing Medications — Deprescribing.
→ On the overall picture of polypharmacy: Polypharmacy in Old Age.
Multimodal pain therapy
Strong, untreated pain triggers delirium — just as do excessively high opioid doses. The middle way: combined therapy with paracetamol, non-opioid analgesics (if kidney function allows), regional procedures and targeted, low opioid administration. Consistent pain therapy for hip fractures, for example through a fascia iliaca block, significantly reduces the risk of delirium.
Delirium screening from admission
The most important sentence: what is not looked for is not found. Structured screening instruments (CAM, 4AT, Nu-DESC) enable detection within a few minutes. Implementation ideally at least once per shift by the nursing staff. A negative screening in the morning says nothing about the screening in the evening — delirium fluctuates over the course of the day. A complementary frailty screening is advisable for risk assessment.
Early treatment of reversible causes
- Recognize urinary tract infections and pneumonia in old age early and treat with antibiotics
- Correct electrolyte disturbances
- Avoid hypoxia — adequate oxygen supply
- Address constipation systematically
- Recognize and treat urinary retention — also relevant in urinary incontinence in old age
Relatives as co-therapists
The presence of familiar caregivers is one of the most effective delirium-prevention factors. Studies consistently show: the more time relatives spend at the bedside, the lower the rate of delirium. This is not nursing relief for the staff — it is evidence-based medicine.
???? When you visit an older relative in hospital: bring glasses, hearing aid, a photo from home, a calendar with the current date. And stay longer than you think necessary. Your mere presence lowers the risk of delirium measurably.
For planned procedures, delirium prevention begins not in the hospital but weeks beforehand:
- Cognitive and physical baseline assessment — ideally via a geriatric assessment
- Medication optimization with discontinuation of delirium-promoting substances
- Targeted training to increase strength before the operation — also for the prevention of sarcopenia
- Nutritional optimization, particularly protein intake
- Treatment of anemia and vitamin D deficiency
- Psychological preparation — informed consent, realistic expectations
- Planning of care after discharge
→ On preoperative risk assessment and prehabilitation: Surgical Risk in Old Age.
Intensive care unit
Delirium rates in intensive care units are 60 to 80 percent — the highest in the entire hospital. Specific prevention strategies:
- Sedation as low as possible (e.g. ABCDE bundle)
- Daily wake-up attempts and assessment of the depth of sedation
- Early mobilization, also in intubated patients
- Actively shape the day-night rhythm, also in the intensive care unit
- Enable family presence wherever possible
In the case of pre-existing dementia
Patients with dementia have the highest delirium risk and the greatest difficulty in using classic screening (because the cognitive deficits already exist without delirium). Here, observation of the course by familiar people helps: “Mother was different yesterday than today” is a valuable clinical clue that should be recorded in the file.
After discharge
The risk of delirium does not end at the hospital door. In the first weeks at home, residual symptoms can persist — or a new delirium can arise, especially in the case of infections or changes of medication. Family-doctor follow-up checks during this phase are mandatory. Geriatric early rehabilitation can also have a stabilizing effect during this transitional phase.
- Ensure glasses, hearing aid and dentures: Labeled, reachable, functioning.
- Bring familiar objects: A photo of the spouse, a small pillow, a particular cup.
- Hand over the current list of medications: Including over-the-counter and herbal preparations.
- Be present: Regularly, even briefly. A familiar voice and face are therapeutically effective.
- Speak up when something is different: “My mother is different today than yesterday. Has a delirium screening been done?” This is not know-it-all behavior — it is co-management.
- Do not accept benzodiazepines as sleeping aids: If offered, ask about alternatives.
- Support mobilization: Get up together, walk a few steps, sit in the chair instead of the bed.
- Stay attentive after discharge: Changes in the first weeks can be after-effects of delirium.
In many hospitals — particularly in orthogeriatric trauma centers and Certified Geriatric Centers — delirium prevention is part of the standard process. Where this is not the case, a targeted request is sensible:
- For planned major operations in patients over 75
- In the case of pre-existing cognitive impairment or previous episodes of delirium — particularly in mild cognitive impairment (MCI)
- In the case of polypharmacy and multimorbidity
- In the case of a current delirium without a clear cause
- After repeated episodes of delirium in earlier hospital stays
- In the case of a question about medication optimization before and after discharge
→ On the systematic geriatric assessment, which classifies delirium risks in a structured way: Geriatric Assessment.
→ On the overall account of delirium: Delirium in Older People.
