A 72-year-old man with a 3-year history of Alzheimer disease presents to the geriatric psychiatry clinic with acute onset of visual hallucinations (seeing people in his room at night), increased agitation, and disorientation to time. His wife reports he was well until 3 days ago. Vital signs are normal. Urinalysis shows pyuria and nitrites. Blood glucose is 320 mg/dL (fasting). Serum sodium is 128 mEq/L. Which of the following is the MOST important initial step in managing this acute behavioral change?

Explanation

## Acute Behavioral Decompensation in Alzheimer Disease ### Delirium Superimposed on Dementia **Key Point:** Acute psychiatric symptoms in AD patients are delirium until proven otherwise. Delirium is a medical emergency caused by underlying systemic illness, NOT a primary progression of AD or a psychiatric disorder requiring psychotropic drugs as first-line therapy. **High-Yield:** The "4 I's" of delirium in dementia: 1. **Infection** (UTI, pneumonia, sepsis) 2. **Intoxication/Iatrogenic** (medications, withdrawal) 3. **Ischemia** (stroke, MI, hypoxia) 4. **Imbalance** (electrolytes, glucose, renal function) ### Clinical Presentation in This Case | Finding | Significance | |---------|-------------| | Acute onset (3 days) | Delirium, NOT AD progression (insidious) | | Visual hallucinations | Common in delirium; less typical of uncomplicated AD | | Pyuria + nitrites | UTI (most common delirium trigger in elderly) | | Hyperglycemia (320 mg/dL) | Uncontrolled diabetes; metabolic delirium | | Hyponatremia (128 mEq/L) | Severe; causes confusion, seizures, death | | Agitation + disorientation | Hyperactive delirium phenotype | **Clinical Pearl:** In an AD patient with acute behavioral change, the rule is: **treat the medical condition first, not the behavior.** Antipsychotics in delirium can worsen outcomes, increase mortality, and mask the underlying cause. ### Management Algorithm ```mermaid flowchart TD A[Acute behavioral change in AD patient]:::outcome --> B{Delirium?}:::decision B -->|Yes: Acute onset + medical signs| C[Identify medical cause]:::action C --> D[Infection?]:::decision D -->|Yes: UTI, pneumonia| E[Treat infection]:::action C --> F[Metabolic?]:::decision F -->|Yes: glucose, Na, renal| G[Correct electrolytes/glucose]:::action C --> H[Medication/Toxin?]:::decision H -->|Yes: drug side effect| I[Adjust/discontinue]:::action E --> J[Behavioral support + treat cause]:::action G --> J I --> J J --> K[Antipsychotic ONLY if severe agitation after medical treatment]:::action B -->|No: Insidious, no medical signs| L[AD progression or primary psychiatric disorder]:::outcome ``` ### Why Antipsychotics Are NOT First-Line 1. **Masking the underlying cause:** Sedating the patient delays diagnosis of UTI, hyperglycemia, or hyponatremia 2. **Increased mortality:** Antipsychotics in delirium are associated with increased cardiovascular events and death 3. **Paradoxical worsening:** Can worsen delirium, increase falls, and prolong hospital stay 4. **Ineffective without treating cause:** Behavioral symptoms resolve only when the medical condition is corrected **Mnemonic: DELIRIUM = Don't use Drugs (antipsychotics) first; Eliminate the underlying cause; Look for Infection/Ischemia/Imbalance; Identify Reversible causes; Use Behavioral support; Medications only if severe after cause is treated; Use low-dose antipsychotic as last resort** ### Correct Sequence 1. **Immediate:** Assess vital signs, glucose, electrolytes, urinalysis, CBC, metabolic panel 2. **Urgent:** Treat identified causes (antibiotics for UTI, insulin for hyperglycemia, hypertonic saline for severe hyponatremia) 3. **Supportive:** Reorientation, familiar environment, adequate sleep, hydration, nutrition 4. **Pharmacologic (if needed after step 2):** Low-dose antipsychotic (haloperidol 0.5–1 mg IM/IV) ONLY for severe agitation that impedes medical care **Warning:** Head CT is NOT the first step unless there are focal neurologic signs or head trauma. Imaging delays treatment of reversible causes. [cite:Harrison 21e Ch 402; Inouye SK, Westendorp RGJ, Saczynski JS. Delirium in elderly people. Lancet. 2014;383(9920):911-922]