Quick Reference
RxDrug of choiceNon-pharmacologic interventions (reorientation, mobilization, sleep protocols, family involvement) are first-line. For severe agitation, haloperidol 0.5-2 mg PO/IM/IV q2-4h PRN (max 10 mg/day).
AltAlternativesOlanzapine 2.5-5 mg IM/ODT q6-8h PRN; quetiapine 12.5-25 mg PO q6-8h PRN (preferred in Parkinson's disease or Lewy body dementia).
⊘AvoidBenzodiazepines (except for alcohol/benzodiazepine withdrawal), anticholinergic drugs (diphenhydramine, oxybutynin, tricyclic antidepressants), and high-potency antipsychotics (e.g., haloperidol) in patients with Parkinson's disease or dementia with Lewy bodies.
DxTest of choiceConfusion Assessment Method (CAM), bedside diagnostic tool with >90% sensitivity and specificity.
ScKey scoreCAM-Severity (CAM-S) for severity tracking; 4AT for rapid screening.
→When to referPersistent delirium >7 days, uncertain diagnosis, severe agitation unresponsive to standard doses, new focal neurologic deficits, suspected NMS, or need for electroconvulsive therapy (ECT) for refractory catatonia.
Delirium is a medical emergency requiring immediate identification of the underlying cause and aggressive non-pharmacologic management. Antipsychotics are used sparingly for severe agitation only. Avoid benzodiazepines and anticholinergics. Treating the precipitant is the definitive therapy.
Delirium is an acute, fluctuating disturbance in attention and cognition that represents a medical emergency in older adults. It affects up to of hospitalized elders and is independently associated with increased mortality, prolonged length of stay, and accelerated cognitive decline. The cornerstone of management is prompt identification of the underlying precipitant (e.g., infection, medication toxicity, metabolic derangement) and implementation of non-pharmacologic interventions. Antipsychotics should be reserved for severe agitation that threatens safety or disrupts essential care.
Overview and Recommendations
Background
- •Delirium is an acute neuropsychiatric syndrome characterized by a disturbance in attention, awareness, and cognition that develops over hours to days and fluctuates in severity. It is not a disease itself but a manifestation of an underlying medical, surgical, or pharmacologic insult. The incidence in hospitalized older adults ranges from 20% to 50%, with rates exceeding 70% in the ICU or postoperative hip-fracture population.
- •The condition carries high stakes: in-hospital mortality is -, and 1-year mortality approaches -. Delirium is also a potent risk factor for long-term cognitive decline, institutionalization, and functional dependence, even after the acute episode resolves. Health care costs attributable to delirium exceed $150 billion annually in the United States.
- •Three clinical subtypes are recognized: hyperactive (agitation, restlessness, hallucinations, easily recognized but least common), hypoactive (lethargy, withdrawal, reduced speech, often missed or misdiagnosed as depression), and mixed (fluctuating between both). Hypoactive delirium carries the worst prognosis and is the most prevalent subtype in older adults, especially those with pre-existing dementia.
- •The central pathophysiology involves cholinergic deficiency, dopaminergic excess, and widespread neuroinflammation. The "final common pathway" hypothesis posits that multiple insults (e.g., surgery, infection, drugs) converge on a vulnerable brain, one already compromised by aging, neurodegeneration, or chronic disease, to produce acute brain failure. The brain's reduced reserve in older adults explains why a minor insult (e.g., a urinary tract infection) can trigger profound delirium.
- •Delirium is distinct from dementia (chronic, progressive, no fluctuation) and depression (mood without cognitive fluctuation). However, the two commonest precipitants are (1) polypharmacy, especially anticholinergics, benzodiazepines, and opioids, and (2) acute infections (UTI, pneumonia). The mnemonic "I WATCH DEATH" (Infectious, Withdrawal, Acute metabolic, Trauma, CNS pathology, Hypoxia, Deficiencies, Endocrine, Acute vascular, Toxins, Heavy metals) helps recall the broad etiologic categories.
Evaluation
- •Suspect delirium in any older adult with an acute change in mental status, especially if the family reports the patient is "not themselves" or if there is a sudden onset of confusion, inattention, or altered level of consciousness. Delirium can be the first (and only) sign of a serious medical illness.
- •Ask about the onset and time course: is the change acute (hours to days)? Does it fluctuate during the day? Is there a clear precipitant (new medication, infection, surgery, fall)? Interview both the patient and a collateral informant (family, caregiver, nursing home staff).
- •Examine the patient's level of consciousness (alert, lethargic, stuporous, coma), attention (digit span, months of the year backwards), and orientation (person, place, time). Use the Confusion Assessment Method (CAM) as the bedside diagnostic tool: requires (1) acute onset and fluctuating course, (2) inattention, and either (3) disorganized thinking or (4) altered level of consciousness. The CAM is >90% sensitive and specific when administered by trained clinicians.
- •Perform a thorough physical examination, including vital signs (tachycardia, hypotension, fever, hypoxia), a targeted neurologic exam (focal deficits, nuchal rigidity, asterixis), and a search for sources of infection (lungs, urine, skin, lines). Check for fecal impaction and urinary retention, both common reversible causes in older adults.
- •Order a basic laboratory panel: CBC, comprehensive metabolic panel (including calcium, magnesium, phosphate), glucose, BUN/creatinine, liver function tests, TSH, and urinalysis with culture. Consider blood cultures if febrile. Obtain an ECG to evaluate for ischemia or arrhythmia and measure QTc if antipsychotics are anticipated.
- •Order pulse oximetry and consider ABG if hypoxia is suspected. An urgent head CT (non-contrast) is indicated if there is a new focal neurologic deficit, head trauma, history of falls, anticoagulation use, or if the patient does not return to baseline within 24-48 hours of treatment.
- •Assess for pain, dehydration, sensory deficits (hearing, vision), and functional impairments (mobility, continence). These are both risk factors for delirium and modifiable targets for management.
- •Use delirium severity scales to track progression: the CAM-Severity (CAM-S) or the Delirium Rating Scale-Revised-98 (DRS-R-98) can quantify the severity and guide treatment response. The 4AT (4-A's Test) is a rapid screening tool (acceptable for non-psychiatrists) that takes <2 minutes.
- •Also consider: EEG if non-convulsive status epilepticus is suspected (especially in patients with known epilepsy, acute stroke, or severe metabolic derangement). Lumbar puncture if CNS infection is suspected (meningitis, encephalitis), contraindicated if mass effect or coagulopathy.
- •Rule out dementia as the sole cause: delirium is superimposed on dementia in up to 70% of cases. Use the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) or collateral history to establish baseline cognitive function. If the patient has known dementia, a change from baseline warrants a delirium workup.
Management
- •First, identify and treat the underlying cause(s): if infection is present, start empiric antibiotics (e.g., ceftriaxone 1 g IV daily for UTI/pneumonia in community-dwelling older adults; adjust for local resistance and allergies). Hold all non-essential medications, especially anticholinergics, benzodiazepines, opioids, and antihistamines. Correct dehydration, electrolyte imbalances, hypoxia, and metabolic disturbances.
- •Implement non-pharmacologic interventions as first-line therapy for all patients: provide a calm, consistent environment with frequent reorientation (verbal cues, clocks, calendars), encourage family presence, ensure adequate lighting, minimize room changes, and reduce nighttime noise and interruptions. Promote early mobilization (sit out of bed, ambulate if safe) and provide hearing and vision aids (glasses, hearing aids) if available.
- •Ensure adequate hydration and nutrition: offer oral fluids frequently, encourage small meals, and avoid unnecessary fasting. Maintain bowel and bladder function (monitor for constipation, catheterize only if absolute necessity). Avoid physical restraints and tethers (IV lines, oxygen tubing, foley catheters) when possible; they often worsen agitation.
- •Use non-pharmacologic sleep protocols: warm milk, back rub, relaxation music, and a quiet room. Avoid pharmacologic sleep aids (e.g., zolpidem, diphenhydramine) as they can worsen delirium. Dim the lights at night and keep the room bright during the day to reinforce circadian rhythm.
- •Reserve pharmacologic sedation for patients with severe agitation that threatens safety (e.g., pulling out IV lines, falling out of bed, harming staff) or prevents essential medical care. The first-line agent is haloperidol 0.5-2 mg PO/IM/IV every 2-4 hours as needed for agitation, with a maximum of 10 mg/day in most guidelines. Monitor QTc before and after administration; if QTc >500 ms, avoid haloperidol and consider alternative antipsychotics.
- •Alternative antipsychotic options: olanzapine 2.5-5 mg IM/ODT every 6-8 hours PRN (less QTc prolongation, but can cause orthostatic hypotension and sedation); quetiapine 12.5-25 mg PO every 6-8 hours PRN (particularly useful in Parkinson's disease or Lewy body dementia due to low D2 receptor affinity; start at 12.5 mg, titrate carefully). Avoid ziprasidone due to QTc risk and limited data in older adults.
- •Avoid benzodiazepines in all forms of delirium except for alcohol or benzodiazepine withdrawal. Benzodiazepines (e.g., lorazepam) can worsen confusion, cause paradoxical agitation, and increase fall risk. If withdrawal is suspected, use a symptom-triggered protocol with lorazepam 0.5-1 mg IV/PO every 2-4 hours as needed.
- •Monitor for adverse effects of antipsychotics: QTc prolongation, extrapyramidal symptoms (dystonia, parkinsonism, akathisia), neuroleptic malignant syndrome (NMS), and orthostatic hypotension. In patients with Parkinson's disease or dementia with Lewy bodies, even low-dose antipsychotics can precipitate severe rigidity and immobility, use quetiapine or clozapine with extreme caution.
- •Consider non-pharmacologic alternatives for agitation: music therapy, pet therapy, therapeutic touch, or a sitter (companion) to provide constant reassurance. De-escalation techniques (speaking calmly, validating emotions, redirecting) are preferred over medication.
- •Do not use physical restraints as a first-line measure; they increase agitation, cause injury, and worsen delirium. If restraints are temporarily necessary to prevent removal of life-sustaining devices (e.g., endotracheal tube), document the indication, use the least restrictive type (e.g., mittens), and reassess every 2 hours.
- •Refer to psychiatry or geriatric medicine if delirium persists >7 days despite treatment of the underlying cause, if the diagnosis is uncertain (possible dementia vs. depression vs. delirium), if there is severe agitation unresponsive to standard doses, or if there are new focal neurologic signs suggesting a structural lesion. Also refer if the patient develops signs of NMS (rigidity, fever, elevated CK, autonomic instability).
- •Discharge criteria: return to baseline mental status (or near-baseline as confirmed by family), stable vital signs, ability to safely perform basic activities of daily living with appropriate support, and a clear discharge plan with follow-up within 1 week. Use a delirium discharge checklist to ensure medication reconciliation, fall prevention education, and cognitive follow-up.
Board Review — High Yield
- •Confusion Assessment Method (CAM), requires acute onset and fluctuating course, inattention, and either disorganized thinking or altered level of consciousness. Most sensitive/specific tool for delirium diagnosis.
- •Hypoactive delirium, most common subtype in older adults (50%+), often missed, associated with worse outcomes than hyperactive type.
- •CAM-S, severity score; higher scores predict longer hospital stay and higher mortality.
- •Non-pharmacologic management (reorientation, mobilization, sleep hygiene, family presence) is the cornerstone of treatment and reduces delirium duration by 30-50%.
- •Haloperidol, first-line antipsychotic for severe agitation; dose 0.5-2 mg; monitor QTc; avoid in prolonged QT, Parkinson's disease, and Lewy body dementia.
- •Benzodiazepines, contraindicated in most delirium (except withdrawal); can worsen confusion and cause paradoxical agitation.
- •Delirium superimposed on dementia, occurs in up to 70% of hospitalized dementia patients; acute change from baseline requires full workup.
- •I WATCH DEATH, mnemonic for causes: Infectious, Withdrawal, Acute metabolic, Trauma, CNS, Hypoxia, Deficiencies, Endocrine, Acute vascular, Toxins, Heavy metals.
- •Prevention, multicomponent programs (e.g., Hospital Elder Life Program, HELP) reduce incidence by 30-40% in hospitalized older adults.
- •Prognosis, in-hospital mortality 10-; 1-year mortality 35-; of patients never return to baseline cognitive function.