Acute Psychosis

Step 1 · Make environment safe
  • Quiet, low-stimulation room · 1:1 sitter if command hallucinations or violent
  • Search & remove dangerous items · involuntary hold if refusing care & dangerous
  • Verbal de-escalation first; offer PO meds before IM (see Acute Agitation)
Step 2 · Rule out organic causes
  • Vitals + glucose + SpO₂ + temp — hypoxia / hypoglycemia / sepsis present like psychosis
  • Exam: focal neuro, neck stiffness, pupils, asterixis, thyroid, track marks
  • Labs: CBC, BMP, Ca, Mg, LFT, NH₃, TSH, UA, UDS, EtOH, β-hCG, ± troponin
  • ECG (QTc) before antipsychotic
  • CT head if new psychosis > 40 y, focal deficit, headache, trauma, or AMS
  • LP if fever, meningismus, immunocompromised — consider autoimmune (anti-NMDA-R) encephalitis
  • DDx: delirium, intoxication/withdrawal, post-ictal, infection, stroke, ICH, B12, thyroid, steroids, ICU psychosis
Step 3 · Antipsychotic doses
  • Olanzapine 10 mg PO/ODT/IM (avoid IM with parenteral benzo or EtOH — hypotension)
  • Risperidone 2 mg PO/ODT
  • Haloperidol 5 mg IM/IV + Lorazepam 2 mg IM/IV + Diphenhydramine 25–50 mg IM/IV ("B52")
  • Ziprasidone 10–20 mg IM — confirm QTc < 500 ms first
  • Droperidol 5 mg IM/IV — fast onset, monitor QTc
  • Avoid antipsychotics if suspected NMS, anticholinergic toxidrome, severe Parkinson's, Lewy-body dementia
Step 4 · Reassess & monitor
  • Q15-min vitals × 1 h after dose · continuous SpO₂ if combined sedatives
  • Watch for acute dystonia → Diphenhydramine 25–50 mg IV or Benztropine 1–2 mg IM/IV
  • Akathisia → Lorazepam 1–2 mg or Propranolol 10–20 mg PO
Step 5 · Disposition
  • Psychiatry consult for all new-onset or decompensated psychosis
  • Medical admission if organic cause; psych admission once medically clear
  • Document capacity, safety plan, voluntary/involuntary status
  • If discharge: outpatient follow-up < 7 days, family support, med reconciliation