Delirium.
Recognize early. Treat the cause, not the behavior. Hypoactive delirium is the most common subtype and the most missed; antipsychotics manage behavior for safety — they do not treat the disorder.
Reviewed October 2026 · verify against current guidelines
Acute care essentials
Delirium.
Recognize early. Treat the cause, not the behavior. Hypoactive subtype is most common and most missed. Antipsychotics manage behavior for safety — they do not treat the disorder.
Recognition
Recognize. Confirm. Subtype.
Definition (DSM-5, all 4 required)
- Disturbance in attention & awareness.
- Acute onset (hours–days) with fluctuating course.
- Additional cognitive disturbance (memory, orientation, language, perception).
- Evidence of an underlying medical cause — not better explained by NCD or coma.
Subtypes — screen everyone; hypoactive is most missed
| Subtype | Prevalence | Recognition | Prognosis |
|---|---|---|---|
| Hyperactive | ~25% | Agitation, hallucinations, hypervigilance. Easy to spot, often over-medicated. | Best (gets attention) |
| Hypoactive | ~30–50% | Lethargy, withdrawal, sluggish, flat affect. Often mistaken for depression or sedation. | Worst — higher mortality, longer LOS |
| Mixed | ~25% | Fluctuates between states; often worse at night (sundowning). | Intermediate |
Differential (the look-alikes)
| Feature | Delirium | Dementia | Depression |
|---|---|---|---|
| Onset | Acute (hrs–days) | Insidious (mo–yr) | Subacute (wks–mo) |
| Course | Fluctuating | Steadily progressive | Persistent low mood |
| Attention | Impaired (key) | Preserved early | Variable, mild |
| Consciousness | Altered / clouded | Clear | Clear |
| Reversibility | Often reversible | Not reversible | Reversible |
Diagnosis & workup
Find the cause.
Screen first — CAM = gold standard; 4AT = fastest
| Tool | How | Threshold | Sens / Spec | Best for |
|---|---|---|---|---|
| CAM | (1) acute + fluctuating AND (2) inattention AND [(3) disorganized OR (4) altered LOC] | 1+2 AND (3 or 4) | 94 / 89% | Ward |
| CAM-ICU | Adapted for nonverbal / ventilated patients | Same logic | 80 / 96% | ICU |
| 4AT | Alertness + AMT4 + months backward + acute change. <2 min, no training. | ≥4 = possible | 88 / 88% | ED / busy ward |
Then think DIMS-R (in every delirious patient)
| Consider | Targeted tests | |
|---|---|---|
| Drugs | New meds in last 7d, anticholinergics, benzos, opioids, steroids, withdrawal (ETOH/benzo/opioid), polypharmacy | Med rec; urine tox; drug levels (digoxin, lithium); CIWA if ETOH |
| Infection | UTI, pneumonia, line, C. diff, meningitis, occult abscess, endocarditis | UA + cx, CXR, blood cx, lactate, LP if meningitis |
| Metabolic | Glucose, Na, Ca, Mg, uremia, hepatic encephalopathy, hypoxia, thyroid, B12/thiamine | CMP, Ca/Mg/PO4, ABG, TSH, ammonia, B12 |
| Structural | Stroke, ICH, SDH (esp anticoagulated), seizure / NCSE, tumor | CT head; MRI if focal + neg CT; EEG if NCSE |
| Retention / Restraints | Urinary retention, fecal impaction, uncontrolled pain, tethers, sleep deprivation | Bladder scan, rectal exam, pain assessment, remove Foley / restraints |
Prevention
Prevent. Bundle care.
High-risk patient (predisposing + precipitating)
| Predisposing | Age ≥65, dementia (strongest single RF), frailty, sensory deficits, prior delirium, polypharmacy, ETOH/substance use, depression. |
|---|---|
| Precipitating | Surgery (hip fx ~50%, cardiac ~30%), severe illness, infection, hypoxia, dehydration, lytes, sleep deprivation, restraints/Foley, ICU, new psychoactive med, withdrawal. |
Bundles (reduce incidence ~40–50%)
| HELP bundle (ward) | ABCDEF bundle (ICU) |
|---|---|
| Orient — clock, calendar, frequent staff reorientation | A Assess, prevent, manage pain (multimodal) |
| Therapeutic activity — conversation, cognitive stim | B Both SAT (sedation off) + SBT (vent wean) daily |
| Early mobility — out of bed daily, PT consult | C Choice of sedation — avoid benzos; prefer dexmed |
| Vision & hearing — glasses, hearing aids on | D Delirium — CAM-ICU q-shift |
| Sleep — non-pharm protocol; protect 10pm–6am | E Early mobility — PT/OT POD#1 when safe |
| Hydration — PO encouragement, IV if needed | F Family engagement — presence, orientation |
Non-pharm management (always first)
| Environment & family | Reorient often (name, place, date). Daytime light, dim/quiet nights. Glasses + hearing aids on. Familiar objects at bedside. Continuity of nursing. Family at bedside, especially overnight. |
|---|---|
| Sleep | Protect 10pm–6am (no labs/vitals unless clinically needed). Cluster nursing care. Avoid benzos and Z-drugs. |
| Mobility | Out of bed for all meals. PT consult. Ambulate ≥3x daily. |
| Physical | Remove Foley / lines ASAP. Avoid restraints (worsen delirium — use 1:1 sitter). Multimodal opioid-sparing analgesia. Address constipation, urinary retention. |
Acute management
Pharmacology is safety, not cure.
APA 2025 (1C): antipsychotics NOT recommended for prevention or to hasten resolution. Use only if de-escalation fails, contributing factors are addressed, AND symptoms cause distress or harm risk. MIND-USA NEJM 2018: haloperidol does not shorten delirium or improve mortality.
Options when behavioral safety requires medication
| Drug | Dose | Role | Caveats |
|---|---|---|---|
| Haloperidol | 0.25–0.5 mg PO/IV/IM q4h PRN; max ~5 mg/24h elderly | Severe agitation with harm risk. Most clinical experience. | QTc (EKG baseline + f/u); EPS. Avoid in PD/LBD. |
| Quetiapine | 12.5–25 mg PO BID or QHS; titrate to 100 mg/d max | Sundowning, sleep, PD/LBD-safe. Less EPS than haloperidol. | Sedation, orthostasis, QTc, anticholinergic at higher doses. |
| Olanzapine | 2.5–5 mg PO/IM/ODT | Alternative when haloperidol contraindicated. IM useful for refusal. | Sedation, anticholinergic. Avoid IM + IV benzo combo. |
| Dexmedetomidine | 0.2–0.7 mcg/kg/hr IV (no bolus in elderly) | APA/PADIS 2025 suggest for major surgery + mechanical ventilation; preferred over benzos. | Bradycardia, hypotension. Continuous monitoring needed. |
| Melatonin / Ramelteon | Melatonin 3–5 mg QHS / Ramelteon 8 mg QHS | APA 2025: NOT recommended for prevention. PADIS 2025 suggests melatonin in ICU. | Evidence conflicting; low harm profile. |
Acute management
Special scenarios.
Standard pharm rules change in specific populations. Recognizing these prevents harm from defaulting to haloperidol or benzos.
Population-specific approaches
| Scenario | Approach | Avoid |
|---|---|---|
| PD / Lewy body | Quetiapine 12.5–25 mg QHS or pimavanserin. Treat motor sx, avoid anticholinergics. | Haloperidol, risperidone, olanzapine (severe EPS, may worsen mortality). |
| ETOH / benzo withdrawal | Benzo-first (CIWA-driven). Phenobarbital alt. Thiamine 100–300 mg IV daily (500 mg IV TID if suspected Wernicke's) before glucose. | Antipsychotic monotherapy (won't prevent seizures or DTs). |
| End-of-life / hospice | Comfort first. Haloperidol 1–2 mg SC q1h PRN or olanzapine SL. Midazolam for refractory terminal agitation. | Aggressive workup if goals are comfort-focused. |
| Post-op (POD#1–3) | Minimize anticholinergics, restart home meds carefully, mobilize early. Dexmed if ventilated. Pain control matters. | Diphenhydramine for sleep, scheduled benzos for anxiety. |
| Mechanical ventilation | Dexmedetomidine over propofol (PADIS 2025). Daily SAT + SBT. CAM-ICU q-shift. | Continuous benzo infusion unless seizure/withdrawal. |
| Hepatic / renal failure | Reduce all doses. Hepatic: prefer LOT benzos (lorazepam, oxazepam, temazepam — no CYP oxidation). Renal: watch lorazepam glycol toxicity with high-dose drips. Lactulose for HE. | Standard adult dosing; long-acting agents. |
Pitfalls & disposition
Don't miss the exit.
Avoid (worsen or perpetuate delirium)
- Benzodiazepines — worsen and prolong delirium. Exceptions: ETOH/benzo withdrawal, seizures, refractory agitation, end-of-life.
- Anticholinergics — diphenhydramine (Benadryl), hydroxyzine, scopolamine, oxybutynin, TCAs, 1st-gen antihistamines, cyclobenzaprine, promethazine. Check Beers list on admission and discharge.
- Opioid excess — escalating PRN doses. Use scheduled multimodal analgesia.
- Antipsychotics in PD/LBD — use quetiapine or pimavanserin only.
- Physical restraints — independently worsen delirium and cause injury. Sitter first.
- Continuing antipsychotics indefinitely — taper before d/c; common failure point.
Discharge checklist
- Antipsychotic tapered or stopped before d/c (not a chronic med).
- Culprit meds not restarted (anticholinergics, benzos, sedative-hypnotics).
- Episode documented in d/c summary — timing, precipitant, interventions, resolution.
- PCP notified with cognitive baseline + follow-up plan.
- Family counseled — persistent symptoms in 30–50% at 6 mo; recurrence risk; dementia link.
- Cognitive follow-up at 4–6 weeks (MMSE or MoCA). Neuropsych referral if persists > 3 mo.
Clinical pearls
- Hypoactive is most common and most missed — screen everyone, not just the agitated.
- Acute + fluctuating = delirium until proven otherwise — even in patients with known dementia.
- Delirium associated with ~3x mortality (OR 3.18) in older inpatients; ~7x in ICU (OR 7.09).
- APA 2025: antipsychotics do NOT treat delirium — reserved for safety when de-escalation fails.
- Sleep matters — but as part of a bundle. Non-pharm sleep alone has mixed RCT evidence; bundles win.
- Up to 40% of episodes are preventable with non-pharm bundles (HELP, ABCDEF).
NCD neurocognitive disorderLOC level of consciousnessCAM Confusion Assessment MethodAMT4 Abbreviated Mental Test – 4LOS length of stayDIMS-R Drugs/Infection/Metabolic/Structural/Retention-RestraintsNCSE non-convulsive status epilepticusHELP Hospital Elder Life ProgramSAT/SBT spontaneous awakening / breathing trialPD/LBD Parkinson disease / Lewy body dementiaEPS extrapyramidal symptomsCIWA Clinical Institute Withdrawal Assessment for alcoholMoCA Montreal Cognitive Assessment
Educational only · Not medical advice. Content reflects published guidelines at time of release and may not apply to every patient. Verify against your institution's protocols and current society recommendations before applying at the bedside.
Sources
Verify against current guidelines and local protocol before acting.
- DSM-5-TR. American Psychiatric Association.
- APA Practice Guideline for the Prevention and Treatment of Delirium (2025).
- SCCM PADIS Guidelines Focused Update. Lewis et al. Crit Care Med 2025 Mar;53(3):e711–e727.
- AGS Beers Criteria 2023 update for potentially inappropriate medication use in older adults.
- NICE CG103. Delirium: prevention, diagnosis and management (2010, updated Jan 2023).
- AGS Postoperative Delirium Clinical Practice Guideline (2014/2015 abstracted).
- MIND-USA. Girard et al. NEJM 2018 — haloperidol/ziprasidone vs placebo in ICU delirium.
- HOPE-ICU. Page et al. Lancet Respir 2013 — haloperidol in ventilated patients.
- SPICE-III. Shehabi et al. NEJM 2019 — early dexmedetomidine in mechanically ventilated adults.
- Aung Thein et al. BMC Geriatrics 2020 — delirium-mortality meta-analysis (OR 3.18; ICU OR 7.09).
- Witlox et al. JAMA 2010 — delirium and long-term outcomes.
- Inouye et al. NEJM 1999 — HELP trial; multicomponent prevention in older inpatients.
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