Emergency Medicine Hub / Neurology & Psychiatry • 3 min read • 3 sections

Acute Psychosis & Decompensated Schizophrenia

Comprehensive emergency evaluation and protocolized psychiatric stabilization of acute psychosis and decompensated schizophrenia: the systematic medical clearance examination, differentiating primary 'functional' psychiatric psychosis (schizophrenia, bipolar mania) from life-threatening secondary 'organic' medical delirium (anti-NMDA receptor encephalitis, CNS infections, neurosyphilis, thyrotoxicosis, structural tumors, metabolic toxicities), high-risk red flags (command auditory hallucinations, capgras delusion, catatonia, Bush-Francis Catatonia Rating Scale), rapid chemical de-escalation and sedation protocols (second-generation atypicals vs. haloperidol/droperidol + lorazepam), and emergency involuntary psychiatric holds.

Resuscitation Quick Actions • First 2 Minutes

High-Acuity

Organic vs Psychiatric Rule

Psychosis in patient > 40 yr, visual hallucinations, abnormal vitals, or fluctuating consciousness = MEDICAL/ORGANIC DELIRIUM

The 5-2-50 Agitation Cocktail

Haloperidol 5 mg IM + Lorazepam 2 mg IM + Diphenhydramine 50 mg IM (prevents acute dystonia while providing rapid sedation)

Droperidol Rapid Sedation

Droperidol 5 to 10 mg IM/IV achieves faster sedation (mean 15–20 min) than haloperidol; monitor QTc on 12-lead ECG

Command Hallucinations

Auditory hallucinations commanding the patient to harm self or others represents an IMMEDIATE indication for involuntary psychiatric hold

Lorazepam Catatonia Challenge

Catatonic stupor, waxy flexibility, mutism: Lorazepam 1 to 2 mg IV; dramatic temporary resolution of symptoms within 10 min confirms catatonia

Anti-NMDA Receptor Encephalitis

Young female + acute psychosis + seizures + dyskinesias + autonomic instability = send CSF for anti-GluN1 NMDA receptor antibodies

Organic vs. Functional Psychosis

Organic (medical etiology) characterized by older age of onset (>40), acute onset, fluctuating course, abnormal vital signs, visual/tactile hallucinations, and altered sensorium. Functional (psychiatric) characterized by younger onset (teens to 20s), auditory hallucinations, clear sensorium, and normal vitals.

Conversion Disorder (Functional Neurological Disorder)

Neurologic symptoms (weakness, non-epileptic seizures, blindness) inconsistent with known neurological pathways (e.g., positive Hoover sign where hip extension paresis resolves during contralateral hip flexion against resistance).

Bottom-Line Clinical Pearl

Acute psychosis is a psychiatric presentation with potential medical lethality. The core emergency objective is ruling out SECONDARY ORGANIC DELIRIUM masquerading as psychosis: new-onset psychosis in patients > 40 years, abnormal vital signs, fluctuating level of consciousness, disorientation to time/place, visual/olfactory/tactile hallucinations, or acute onset over hours are ORGANIC until proven otherwise (check glucose, toxic screen, CT head, lumbar puncture for anti-NMDA encephalitis). In contrast, primary schizophrenia typically presents in young adults (ages 18–30) with auditory hallucinations, paranoid delusions, flat affect, clear sensorium, and orientation to person, place, and time. For acute severe agitation or violent behavior: administer Haloperidol 5 mg IM (or Droperidol 5 mg IM) + Lorazepam 2 mg IM + Diphenhydramine 50 mg IM ('the 5-2-50 cocktail'). For catatonia (mutism, posturing, waxy flexibility), perform the Lorazepam Challenge (1–2 mg IV); rapid reversal confirms catatonia.

1. Medical Clearance: Primary Psychiatric vs. Secondary Organic Delirium

The primary emergency responsibility during a 'psychiatric clearance' evaluation is to ensure that a medical, surgical, or toxicological illness is not masquerading as a psychiatric illness. Differentiating features are stark:

Clinical Parameter	Primary 'Functional' Psychiatric Psychosis (Schizophrenia/Bipolar)	Secondary 'Organic' Medical Delirium (Infection, Toxin, CNS)
Age of Onset	Late teens to late 20s (rarely presents de novo after age 40)	Any age; strongly suspect in patients > 40 years with new-onset psychiatric symptoms.
Onset Speed	Gradual, insidious progression over weeks to months (prodromal phase)	Acute or subacute onset over hours to days.
Vital Signs	Normal (unless agitated)	Abnormal: fever, severe hypertension, tachycardia, hypoxia.
Level of Consciousness	Completely awake and alert; stable cognitive baseline	Fluctuating level of consciousness (waxing and waning alertness, lethargy, somnolence).
Orientation & Cognition	Oriented x 3 or 4 (oriented to person, place, and time); intact memory	Disoriented, poor attention span, impaired short-term memory, confusion.
Hallucination Types	Predominantly Auditory (voices conversing, commenting, or commanding)	Predominantly Visual, Tactile, or Olfactory (insects crawling, seeing animals/shadows, smelling burning rubber).

2. Acute Agitation & Rapid Chemical De-escalation

Sedation Regimen	Drugs & Doses	Administration Route & Clinical Pearl
The '5-2-50' Combination	Haloperidol 5 mg + Lorazepam 2 mg + Diphenhydramine 50 mg	IM injection (can be combined in single syringe). Haloperidol provides D2 blockade; Lorazepam provides GABA-A sedation; Diphenhydramine prevents acute dystonic reactions and enhances sedation.
Droperidol Monotherapy	Droperidol 5 to 10 mg	IM or IV. Faster onset (15–20 minutes) and significantly lower need for repeat sedation compared to haloperidol. FDA black-box warning for QT prolongation is vastly overstated at doses $\le 10\text{ mg}$, but baseline ECG is prudent if feasible.
Ketamine Dissociation (Severe Violence)	Ketamine 4 to 5 mg/kg IM OR 1 to 2 mg/kg IV	IM/IV. Reserved for extreme violent combative behavior threatening immediate physical harm to staff; rapid dissociation within 2–4 minutes; maintain continuous pulse oximetry and capnography.
Second-Generation Oral Options	Olanzapine 10 mg ODT OR Risperidone 2 mg ODT	Oral orally disintegrating tablet (ODT). Preferred for cooperative, moderately agitated patients who agree to oral medication.

3. Catatonia & The Lorazepam Challenge

Catatonia is a life-threatening neuropsychiatric syndrome occurring in schizophrenia, severe mood disorders, and medical illnesses. Patients present with mutism, immobility, stupor, staring, waxy flexibility (limbs remain in positions placed by examiner), or posturing. Left untreated, it progresses to Malignant Catatonia with autonomic collapse, hyperthermia, and death.

The Lorazepam Challenge Test: Administer Lorazepam 1 to 2 mg IV push. In a patient with true catatonia, there is a dramatic, temporary relief of symptoms (the patient begins speaking, moving freely, and eating) within 5 to 10 minutes of injection without sedation! A positive challenge confirms catatonia and guides high-dose scheduled benzodiazepine therapy or emergent Electroconvulsive Therapy (ECT).

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