Background
Definition
- An acute brain dysfunction syndrome of fluctuating levels of consciousness
- Cardinal features:
- altered mental status and fluctuating course
- inattention
- altered level of consciousness (i.e. RASS not zero) OR disorganized thinking
Differential Diagnosis
Life-threatening causes (WHHHHIMPS)
- Wernicke's or alcohol withdrawal
- Hypoxia/hypercarbia
- Hypoglycemia
- Hypertensive emergency
- Hyperthermia/hypothermia
- Intracerebral hemorrhage
- Meningitis/encephalitis
- Poisoning
- Status epilepticus
DIMES
- Drugs
- Iatrogenic
- Polypharmacy
- Opioids (too much or too little)
- Diphenhydramine
- Benzodiazepines
- Abuse: alcohol
- Poisoning
- Withdrawal
- Iatrogenic
- Infections
- Metabolic
- Endocrine: thyroid, parathyroid, pancreas, pituitary, adrenals
- Electrolytes: sodium, calcium, magnesium, potassium
- Hypoglycemia/hyperglycemia
- Hypoxemia/hypercarbia
- Hypoosmolar/hyperosmolar
- Inborn errors of metabolism: porphyria, Wilson disease
- Nutrition: Wernicke's, B12 deficiency, niacin deficiency
- Environmental
- Surroundings, room changes, lack of sunlight indicating day & night
- Structures & organs
- CNS
- Cardiac: heart failure
- Renal: AKI/CKD
- Gastrointestinal: constipation, volvulus
- Genitourinary: urinary retention
Management
- Treat underlying causes
Pharmacologic
- Opioid neurotoxicity:
- Switch opioid
- Dose reduction
- Hydration
- Medications: stop medication
- Dehydration: IV or hypodermoclesis (fluid given subcutaneously)
- Hypercalcemia: IV bisphosphonate (zoledronate/pamidronate)
- Infection: antibiotics
- Hepatic encepalopathy: lactulose
- Brain metastases: corticosteroids (e.g. dexamethasone)
Antipsychotics
- Mild
- Elderly: haloperidol 0.5 mg PO/SQ/IV/IM q4h prn
- End-of-life: haloperidol 0.5-1 mg po or subcut daily or BID + haloperidol 0.5-1 mg po/SC q1h prn
- Moderate
- Haloperidol 2-2.5 mg po/sc bid or tid + haloperidol 2 mg po/sc q1h prn
- Or methotrimeprazine 5-12.5 mg po/sc bid or tid + prn
- Severe
- Elderly: haloperidol 1 mg, or quetiapine 12.5 mg if long QT
- Midazolam 2.5-5 mg sc stat once + haloperidol 5 mg sc stat
- Or methotrimeprazine 25 mg sc stat then po/sc
- Follow with haloperidol 2.5-5 mg sc q30min prn (max 10-15 mg/day)
- Sundowning
- Alternatives
Non-pharmacologic
- Reduce stimulation
- Low ambient light
- Low noise
- Correct sensory deficits (glasses, hearing aids)
- Gentle, repeated reassurances (but labour intensive)
- Do not use physical restraints
