376.1 🎓 醫學生版

376.1.0.1 📌 一頁重點

376.1.0.1.1 Definition (DSM-5)

376.1.1 Core Features

Disturbance in attention + awareness (reduced ability to focus, sustain, shift attention)
Develops over short period (hours to days) — represents change from baseline
Fluctuates during the day
Additional cognitive disturbance (memory, orientation, language, perception)
NOT better explained by another neurocognitive disorder
Evidence of physiological cause (medical, drug, withdrawal, toxin, multifactorial)

376.1.2 Hallmark

Inattention (most characteristic feature)
“Where is the patient’s attention?”

376.1.2.0.1 Subtypes

376.1.3 Hyperactive (25%)

Agitation, restlessness
Easier to recognize
Hallucinations, delusions
May be aggressive

376.1.4 Hypoactive (50%)

Lethargy, withdrawn
Often missed (worst prognosis)
Decreased response
Confused with depression

376.1.5 Mixed (25%)

Fluctuates

376.1.5.0.1 Epidemiology

~ 20% hospitalized older adults
50-80% ICU patients
30% post-surgical elderly
70% post-hip fracture
90% terminal illness

376.1.5.0.2 Predisposing Factors

Age > 65
Pre-existing dementia (most important)
Prior delirium
Multi-comorbidity
Severe illness
Functional impairment
Sensory impairment (visual, hearing)
Depression
Substance use disorder
Frailty

376.1.5.0.3 Precipitating Factors

376.1.6 Medications (Most Common Cause)

Anticholinergics (oxybutynin, scopolamine, diphenhydramine, TCAs)
Benzodiazepines
Opioids (especially meperidine — accumulates normeperidine)
Sedatives
Antiparkinsonian (anticholinergic effect)
Antiepileptics (phenytoin)
Steroids
Many others

376.1.7 Infection

UTI (especially elderly)
Pneumonia
Sepsis
CNS infection
COVID-19 (significant)

376.1.8 Metabolic

Hypoglycemia, hyperglycemia
Hyponatremia, hypernatremia
Hypercalcemia, hypocalcemia
Hypomagnesemia
Uremia
Hepatic encephalopathy
Hypothyroidism, hyperthyroidism
Adrenal insufficiency

376.1.9 Withdrawal

Alcohol (DTs — delirium tremens)
Benzodiazepines
Opioids

376.1.10 Hypoxia, Hypercapnia

376.1.11 Stroke, TBI, Subdural Hematoma, Seizure (Post-Ictal)

376.1.12 Surgery + Anesthesia

Post-operative delirium common in elderly
Hip fracture (especially)
Cardiac surgery
Multifactorial

376.1.13 ICU Factors

Sleep deprivation
Sensory overload/deprivation
Immobilization
Restraints
Multiple medications

376.1.14 Other

Pain (especially undertreated)
Urinary retention, constipation
Dehydration
Malnutrition
Bedrest
Sleep deprivation

376.1.14.0.1 Assessment

376.1.15 Tools

Confusion Assessment Method (CAM):
- 1. Acute onset + fluctuating + (2) Inattention + (either) (3) Disorganized thinking OR (4) Altered LOC
CAM-ICU: for ICU/intubated patients
Delirium Rating Scale
MMSE/MoCA: cognitive screening

376.1.16 History

Baseline mental status (collateral!)
Time course
Recent changes (meds, surgery, illness)
Functional status

376.1.17 Exam

Vital signs
General + focused neuro
Look for asterixis, myoclonus
Cranial nerves, motor, sensory

376.1.18 Labs

CBC
Electrolytes, calcium, magnesium
Glucose
BUN/Cr
LFTs, ammonia
TFTs
B12, folate
UA + culture
CXR
ECG
Drug levels (digoxin, lithium, ASMs)
Toxicology screen
Blood cultures if febrile

376.1.19 Imaging + Specialized

CT head if focal deficit, trauma, suspected stroke/bleed
LP if meningitis suspected
EEG if seizures suspected (NCSE)

376.1.19.0.1 Differential Diagnosis

376.1.20 Delirium vs Dementia

Feature	Delirium	Dementia
Onset	Hours-days	Months-years
Course	Fluctuating	Progressive
Consciousness	Altered	Clear (usually)
Attention	Impaired (hallmark)	Normal early
Reversibility	Often reversible	Usually not
Sleep-wake	Disrupted	Variable

376.1.21 Delirium Superimposed on Dementia

Very common
High-risk hospitalized older adults
Worsens prognosis

376.1.22 Other Differentials

Depression
Mania
Psychosis (functional)
Aphasia
Status epilepticus (NCSE)

376.1.22.0.1 Management

376.1.23 Non-Pharmacologic (FIRST-LINE)

HELP Program (Hospital Elder Life Program): - Multicomponent intervention - Reorientation (clocks, calendars, communication) - Sleep enhancement (non-pharm) - Mobilization - Visual + hearing aids - Hydration + nutrition - Pain management - Avoid restraints - Family involvement

Environmental: - Quiet, well-lit during day, dark at night - Familiar objects - Clock, calendar visible - Glasses, hearing aids - Family at bedside

Medical Optimization: - Identify + treat underlying cause(s) - Discontinue/minimize culprit drugs - Treat infection - Correct electrolytes - Manage pain (acetaminophen first; minimize opioids; avoid meperidine) - Bowel + bladder regularity - Adequate hydration + nutrition - Sleep hygiene (no daytime naps if possible, melatonin)

376.1.24 Pharmacologic (LAST RESORT)

Indications: - Severe agitation - Danger to self/others - Distress unrelieved by non-pharm - Interfering with essential medical care

Choice: - Haloperidol 0.5-1 mg PO/IM/IV (low dose, especially elderly) - Atypical antipsychotics: - Quetiapine 12.5-50 mg (preferred for PD, DLB) - Risperidone 0.25-1 mg - Olanzapine 2.5-5 mg - AVOID: - Benzodiazepines (paradoxical worsening) — EXCEPT for alcohol/BZD withdrawal - Anticholinergic agents - Caveats: - QT prolongation (haloperidol, atypicals) — check ECG - EPS, NMS, parkinsonism - Mortality black box warning in dementia - Use lowest dose, shortest duration

Alpha-2 Agonists: - Dexmedetomidine (ICU sedation) — alternative to propofol/BZDs; less delirium

376.1.25 Special Situations

Alcohol Withdrawal Delirium (DTs): - BZDs first-line (lorazepam, diazepam) - Thiamine (before glucose) - Glucose - Magnesium - Phenobarbital alternative - ICU level care for severe

ICU Delirium: - Minimize BZDs - Dexmedetomidine over BZDs - Sleep promotion - Early mobilization (ABCDEF bundle) - Daily SAT/SBT - Avoid restraints

Terminal Delirium: - Symptom management - Consider haloperidol or atypicals for distress - Family communication

376.1.25.0.1 Consequences

Prolonged hospital stay (5-10 days)
↑ Mortality (in-hospital + post-discharge)
↑ Institutionalization
Accelerated cognitive decline
↑ Functional impairment
↑ Healthcare costs
May persist months in some

376.1.25.0.2 Prevention

Multicomponent non-pharm (HELP program)
Geriatric consultation
Avoid high-risk medications
Pre-op optimization
Early mobilization post-op
Sleep promotion
Adequate analgesia (non-opioid first)

376.1.25.1 🩺 床邊速查

Delirium DSM-5: acute + fluctuating + inattention + cognitive + organic cause
Hallmark: inattention
Subtypes: hyperactive (25%) vs hypoactive (50% — often missed) vs mixed
CAM: 4 criteria
Common precipitants: meds (#1 anticholinergics, BZDs, opioids), infection, metabolic, withdrawal, surgery, ICU
Workup: CAM + meds review + labs + selective imaging
Treatment: non-pharm first (HELP) + treat underlying + pharm last resort (low-dose haloperidol or atypical, AVOID BZDs except withdrawal)
Dexmedetomidine preferred over BZDs in ICU
Consequences: ↑ mortality + ↑ stay + ↑ institutionalization + accelerated dementia