DM
Didactic Med Where Evidence Meets Excellence
CLEAR THE FOG
SCCM PADIS 2025 · NICE 2023 · ACEP · ACR 2024 · Verified April 2026

Altered
Mental Status

A clinician-minded learning console for the undifferentiated patient whose brain is not behaving normally. Separate arousal from attention, find reversible killers fast, localize dangerous CNS disease, and engineer a defendable disposition — without anchoring on "psych" or "old age."

AEIOU
TIPS
The differential
11-letter framework: every reversible cause of AMS, in order.
15
GCS · FOUR · 4AT
Three scales for arousal, brainstem, attention.
8
Toxidromes
Pupils + skin + bowel + temp + ECG patterns.
21
Antidotes
Dose-specific reversals — naloxone to fomepizole.
RAS attention memory orient visual GCS FOUR 4AT CAM
ArousalRAS-driven. GCS, FOUR Score. Hypoxia, glucose, drugs, structural.
AttentionCortical. Delirium. 4AT, CAM. The "fluctuation" cue.
Don't anchor"Psych" + "dementia" + "old age" hide treatable killers.
Treat & diagnoseSugar, oxygen, naloxone, thiamine, antibiotics — in parallel.
First-Pass Recognition

First Decide: Arousal, Attention, or Behavior?

AMS language gets sloppy. Good clinicians split it into level of consciousness, attention, cognition, behavior, and focal neurologic signs. Then run AEIOU-TIPS to make sure no reversible killer escapes the differential.

!
Red-flag pattern

Airway threat, hypoxia, shock, glucose abnormality, fever or hypothermia, meningismus, focal neurologic deficit, seizure or postictal state, head trauma, anticoagulant use, severe headache, new coma, recognizable toxidrome, or rapidly worsening confusion → emergency evaluation. Always check fingerstick glucose. Always ask about medications, alcohol, and last meal.

Arousal

Coma, stupor, lethargy

Think bilateral hemispheres, brainstem (RAS), or toxic-metabolic suppression. Hypothermia, hypoglycemia, sedatives, opioids, anesthetics, structural lesions, postictal, or hepatic/uremic.

Attention

Delirium

Acute, fluctuating inattention with altered awareness or cognition. Hypoactive delirium (quiet, withdrawn) is the silent miss — twice as common as hyperactive, harder to detect, worse outcomes.

Focal

Structural disease

Focal deficit, gaze deviation, aphasia, anisocoria, papilledema, severe headache, anticoagulation, or trauma → push imaging and stroke / neurosurgical pathways. Don't wait for full workup.

Behavior

Agitation, psychosis

Protect staff and patient — but don't anchor. Intoxication, withdrawal, infection, endocrine disease, seizure, hypoxia, stroke, encephalitis, metabolic crisis can all look like a primary psychiatric presentation.

AEIOU-TIPS — The Reversible Differential

Eleven letters cover the dangerous and treatable causes of AMS. Run it on every undifferentiated patient — especially when the diagnosis isn't obvious in the first 30 seconds.

A
Alcohol Intox / withdrawal · Wernicke
E
Endo / Electro Na, Ca, glucose, thyroid, adrenal
I
Insulin Hypo / hyperglycemia · DKA / HHS
O
Opiates / O₂ Hypoxia · CO · methemoglobin
U
Uremia AKI · CKD · liver failure
T
Trauma / Temp TBI · hyperthermia · hypothermia
I
Infection Sepsis · meningitis · encephalitis · UTI
P
Poison / Psych Toxidromes · serotonin · NMS
S
Stroke / Seizure Ischemic · hemorrhagic · NCSE · postictal
+
Shock Hypoperfusion · arrhythmia · hypertensive emerg.
+
Space-Occ. Tumor · abscess · hydrocephalus · CVST
Bedside Scales · Validated Tools

Three Scales, Three Brains

No single scale captures all AMS. Pair them: GCS or FOUR for arousal/coma, 4AT or CAM for delirium, RASS for sedation, and CIWA-Ar for alcohol withdrawal. Document baselines and trends — single numbers without context mislead.

Glasgow Coma Scale (GCS)

Teasdale & Jennett · Lancet 1974 · range 3–15
DomainResponsePts
Eye (E)Spontaneous opening4
EyeTo verbal command3
EyeTo pain2
EyeNone1
Verbal (V)Oriented5
VerbalConfused conversation4
VerbalInappropriate words3
VerbalIncomprehensible sounds2
VerbalNone / intubated (T)1
Motor (M)Obeys commands6
MotorLocalizes to pain5
MotorWithdraws from pain4
MotorDecorticate flexion3
MotorDecerebrate extension2
MotorNone1
GCS 13–15
Mild
Conversational; minor injury
GCS 9–12
Moderate
Obtunded; close monitoring
GCS ≤8
Severe
Consider intubation for airway protection
GCS 3
Coma
No response · ICU level

FOUR Score

Wijdicks · Ann Neurol 2005 · range 0–16
DomainResponse (range 0–4)
Eye (E)Open / tracking / open to voice / open to pain / closed
Motor (M)Obeys commands · localizing · flexion · extension · none
Brainstem (B)Pupil + corneal reflexes (and cough)
Respiration (R)Pattern: regular · Cheyne-Stokes · irregular · apneic / vent

Why over GCS? Testable in intubated patients (no verbal score needed), assesses brainstem reflexes, identifies locked-in syndrome, and stages herniation. Recommended in neurocritical care.

4AT — Delirium Detection

MacLullich · Age Ageing · range 0–12
ItemScore
① Alertness0 or 4
② AMT4 (age, DOB, place, year)0 / 1 / 2
③ Attention (months Dec→Jan)0 / 1 / 2
④ Acute / fluctuating change0 or 4

Cutoffs: ≥4 possible delirium ± cognitive impairment; 1–3 possible cognitive impairment; 0 delirium / severe impairment unlikely. Sensitivity/specificity ~88% pooled. NICE 2023 endorsed.

CAM & CAM-ICU

Inouye 1990 · Ely 2001 (ICU)
FeatureRequired for delirium
① Acute onset / fluctuatingYES
② InattentionYES
③ Disorganized thinkingOR
④ Altered consciousnessOR

Algorithm: Delirium = Feature 1 AND 2, PLUS 3 OR 4. CAM-ICU uses RASS first (must be ≥−3) and standardized attention/thinking probes — validated for ventilated patients.

RASS — Sedation/Agitation

Sessler 2002 · range −5 to +4
ScoreState
+4 / +3Combative / very agitated
+2 / +1Agitated / restless
0Alert & calm — target
−1 / −2Drowsy / light sedation
−3 / −4Moderate / deep sedation
−5Unarousable

SCCM PADIS 2025: Target light sedation (RASS −2 to 0) in ventilated adults. Suggests dexmedetomidine over propofol when reducing delirium is a priority.

First 5 Minutes · Stabilization Script

The Bedside Stabilization Script

The first pathway is not elegant. It's deliberately blunt: oxygen, sugar, circulation, temperature, toxin rescue, brain catastrophe, sepsis. Most of these run in parallel — not in sequence.

0–1 min

Airway & Breathing

Position, suction, oxygen, capnography. Assess gag/cough. Intubate for GCS ≤8, loss of protective reflexes, or impending respiratory failure. RR and pattern matter (Cheyne-Stokes, Biot's, Kussmaul).

0–2 min

Glucose & Perfusion

Fingerstick glucose now — hypoglycemia is the most common reversible mimic of stroke and seizure. Treat <60 mg/dL with D50W 25 g IV (50 mL of 50%) or glucagon 1 mg IM if no IV. Pulses, BP, rhythm strip, temperature.

0–3 min

Toxin Rescue

Opioid toxidrome → naloxone 0.04–0.4 mg IV titrate to ventilation. Malnourished / EtOH / hyperemesis → thiamine 500 mg IV TID (Wernicke prophylaxis/treatment). Don't withhold dextrose for thiamine; give them together.

0–5 min

Brain Emergencies

Focal deficit, gaze deviation, anisocoria, severe headache, anticoagulation, papilledema → NCCT immediately. Persistent AMS post-seizure or eye deviation → consider NCSE → EEG. Meningismus + fever → empiric Abx + acyclovir, then LP.

parallel

Sepsis & Metabolic

Surviving Sepsis hour-1: lactate, blood cultures, broad-spectrum antibiotics within 1 h, 30 mL/kg crystalloid for hypoperfusion, vasopressors for MAP <65. Check Na, Ca, NH₃, acid-base, salicylate, acetaminophen.

Engine Room · Six Decision Frames

Pick the AMS Engine

Six high-yield decision frames. Click each to reveal the question, the action, and the trap. Use the toxidrome table and antidote cards below for specific dosing.

Altered Mental Status Engines

Hypoxia, Shock & Temperature

Before chasing rare diagnoses, correct the physiology that makes every brain fail: oxygen delivery, ventilation, perfusion, and temperature. The cheapest and fastest interventions live here.

Oxygen & CO₂ Hypoxia, hypercapnia, carbon monoxide (cherry-red, low-normal SpO₂ misleads), and severe anemia can all present as confusion, agitation, or coma.
Perfusion Shock of any type, arrhythmia, hypertensive emergency (PRES), and severe dehydration produce encephalopathy long before vital signs scream.
Temperature Heat stroke, NMS, serotonin syndrome, malignant hyperthermia, hypothermia, and septic fever all alter cognition. Treat actively cool/warm — temperature is therapy.
Toxidromes · Recognition Patterns

The Eight Toxidromes

Pupils, skin, bowel sounds, temperature, and ECG intervals beat broad urine drug screens for the first call. Match the pattern, find the antidote, treat the airway/circulation simultaneously.

ToxidromeMental statusPupilsSkin / tempBowelCardioAntidote / Tx
Opioidheroin · oxy · fentanyl · methadone Sedation, coma, ↓RR Pinpoint (miosis) Cool, may be cyanotic ↓ bowel sounds ↓ HR, ↓ BP Naloxone 0.04–0.4 mg IV titrate
Sympathomimeticcocaine · amphetamine · MDMA · meth · PCP Agitation, psychosis, sz Mydriasis (dilated) Diaphoretic, hot Normal/↑ ↑ HR, ↑ BP, arrhythmia Benzos · cool · avoid β-blockers
AnticholinergicTCAs · antihist · diphenhydramine · jimson · scopolamine Agitated delirium Mydriasis Hot, dry, flushed ↓ bowel · urinary retention ↑ HR, QRS/QT widening Physostigmine (selected) · NaHCO₃ for TCA
Cholinergicorganophosphates · carbamates · nerve agents Confusion, sz, coma Miosis Diaphoretic, salivating (SLUDGE) Hyperactive, vomiting, diarrhea Brady, bronchospasm Atropine + pralidoxime (2-PAM)
Sedative-hypnoticbenzos · barbiturates · zolpidem · GHB Sedation, coma, slurred Variable / normal Cool, normal Normal ↓ HR, ↓ BP, ↓ RR Supportive · flumazenil rarely (sz risk)
Serotonin Syndr.SSRI + MAOI/tramadol/linezolid · MDMA Agitation, confusion Mydriasis Hyperthermic, diaphoretic ↑ bowel sounds ↑ HR · clonus, hyperreflexia Stop agent · benzos · cyproheptadine
NMSantipsychotics · antiemetics (metoclopramide) Stupor, mutism Normal Hyperthermic, diaphoretic Normal Autonomic instability · "lead-pipe" rigidity Stop agent · cool · dantrolene · bromocriptine
EtOH withdrawalEtOH · benzo / barbiturate withdrawal Tremor, agitation, sz, DTs Mydriasis Diaphoretic Nausea ↑ HR, ↑ BP Benzos (CIWA-driven) · thiamine · folate
Antidote Protocols · Dose-Specific

Reversal & Rescue Drugs

When a toxidrome is identified or strongly suspected, dose matters. Below are the high-yield acute antidotes with adult doses. Always check current institutional protocol and pharmacy before administration; some agents have narrow therapeutic windows or significant adverse effects.

Naloxone Opioid reversal

IV: 0.04–0.4 mg q2–3min titrate to RR >10 / adequate vent
IN: 4 mg · IM: 0.4–2 mg · drip: 2/3 wake-up dose/hr
Goal is adequate ventilation, not full alertness — overshoot precipitates withdrawal in chronic users. Half-life ~30 min; observe ≥2 h. Long-acting opioids (methadone, fentanyl patches) often need infusion. Nalmefene is a longer-acting alternative.

Thiamine Wernicke

Established Wernicke: 500 mg IV TID × 3 days
Prophylaxis (alcohol, malnutrition): 100–200 mg IV/IM × 3–5 days
Give before or with carbohydrate in high-risk patients (alcohol use, hyperemesis, post-bariatric, malnutrition, refeeding). Caine criteria: 2 of 4 (dietary deficiency, oculomotor abnormalities, cerebellar dysfunction, altered mentation/memory). Low risk; high reward.

Dextrose Hypoglycemia

D50W: 25 g (50 mL) IV push · or D10W 250 mL
Glucagon: 1 mg IM/SC if no IV access
Recheck glucose at 15 min. Sulfonylurea-induced hypoglycemia can recur — admit, octreotide 50 µg SC q6h. Pediatrics: D25W 2–4 mL/kg. Don't wait for confirmatory lab if POC glucose is low.

Flumazenil Use with caution

If used: 0.2 mg IV over 15 sec, repeat to 1 mg
Avoid in chronic benzo users, mixed overdose, TCA co-ingestion, sz history
Reverses pure benzo overdose but can precipitate refractory seizures and death. Most overdoses are mixed and don't need it. Reserved for iatrogenic over-sedation in benzo-naïve patients or known isolated benzo overdose.

NaHCO₃ TCA / salicylate

TCA cardiotoxicity: 1–2 mEq/kg IV bolus, repeat for QRS >100 ms
Salicylate: target urine pH ≥7.5, infusion 150 mEq in 1 L D5W
Sodium load + alkalinization. TCA: continuously monitor QRS; QRS >100 ms or terminal R in aVR ↑ ventricular dysrhythmia risk. Salicylate: alkalinize urine to trap salicylate, hemodialysis if level >100 mg/dL or severe symptoms.

NAC Acetaminophen

IV: 150 mg/kg → 50 mg/kg over 4h → 100 mg/kg over 16h
Use Rumack-Matthew nomogram if single ingestion >4 h
Maximum benefit if given within 8 hours of ingestion, but still useful even later (especially if already in liver injury). Treat empirically while awaiting level if presentation >8 h. Watch for anaphylactoid reactions during loading.

Hydroxocobalamin Cyanide / smoke

Adult: 5 g IV over 15 min, repeat 5 g if needed (max 10 g)
Peds: 70 mg/kg (max 5 g)
First-line for smoke inhalation with AMS, lactic acidosis, hypotension. Turns urine red. Alternative: amyl nitrite + sodium nitrite + sodium thiosulfate kit (caution: methemoglobinemia).

Fomepizole Methanol / EG

Loading: 15 mg/kg IV over 30 min
Maintenance: 10 mg/kg q12h × 4, then 15 mg/kg q12h
Inhibits alcohol dehydrogenase. Indications: methanol or ethylene glycol level >20 mg/dL, suspected ingestion + osmolar gap >10, or metabolic acidosis with anion gap. Hemodialysis for severe acidosis or end-organ injury.

3% Saline Severe hyponatremia

Symptomatic (sz, coma): 100–150 mL bolus, may repeat ×2
Goal: ↑ Na 4–6 mEq/L in first 6 h, max 8–10 mEq/24h
European Hyponatremia Guideline. Overcorrection risk = osmotic demyelination syndrome (locked-in, dysarthria, dysphagia). High-risk groups (chronic alcoholism, malnutrition, hypokalemia, liver disease) need slower correction. Reverse with D5W ± DDAVP if overshooting.
Status Epilepticus · Time-Critical Ladder

The Anti-Seizure Ladder

Convulsive status epilepticus = continuous or recurrent convulsions ≥5 min without recovery (operational definition). Each treatment failure escalates by ~10 minutes. Mortality >20% if >60 min duration.

1

First-line: Benzodiazepines

0–5 min · IV access available

Lorazepam 4 mg IV (0.1 mg/kg, max 4 mg) — repeat once at 5 min if needed.
IM (no IV): Midazolam 10 mg IM (0.2 mg/kg, max 10 mg) — RAMPART trial: equivalent to IV lorazepam.
PR (peds, no IV): Diazepam 0.2–0.5 mg/kg PR · IN: midazolam 0.2 mg/kg.

2

Second-line: Antiseizure medication

5–20 min · ESETT trial: all three equivalent

Levetiracetam 60 mg/kg IV (max 4500 mg) over 5–10 min — preferred (no enzyme induction, fewer interactions).
Fosphenytoin 20 mg PE/kg IV (max 1500 mg) at 150 mg PE/min — monitor BP, ECG.
Valproate 40 mg/kg IV (max 3000 mg) over 10 min — avoid in pregnancy, hepatic disease.

3

Third-line: Refractory SE — Continuous infusion

20–60 min · ICU + cEEG required

Midazolam 0.2 mg/kg load → 0.05–2 mg/kg/h drip · or
Propofol 1–2 mg/kg load → 30–200 µg/kg/min (watch for PRIS) · or
Pentobarbital 5–15 mg/kg load → 0.5–5 mg/kg/h. Target burst suppression on EEG × 24–48 h, then taper.

4

Super-Refractory SE

>24 h despite 3rd-line · Mortality 30–50%

Add: ketamine 1.5 mg/kg load → 1–10 mg/kg/h, inhaled isoflurane, magnesium for eclampsia, pyridoxine for INH overdose, methylprednisolone for autoimmune encephalitis (especially anti-NMDA). Search relentlessly for triggers: stroke, infection, autoimmune, metabolic, drug withdrawal, paraneoplastic.

!
Don't miss nonconvulsive status epilepticus (NCSE)

Persistent unexplained AMS, fluctuating coma, subtle eye deviation or twitching, postictal state lasting >30 min, or cortical/lobar hemorrhage → continuous EEG. NCSE is invisible without EEG and accounts for ~5–10% of unexplained AMS in the ED. Treat with the same ladder as convulsive SE.

Delirium Care · NICE 2023 + SCCM PADIS 2025

Delirium Is Acute Brain Failure — Treat the Cause

Delirium ≠ dementia. Dementia is the baseline; delirium is the acute change. The diagnostic act is proving what changed and when. Treatment is finding and removing the trigger — not adding an antipsychotic.

Detect

Use a validated tool

4AT, CAM, CAM-ICU, or local validated tool. Don't rely on "seems fine" or casual conversation. Hypoactive delirium (quiet, withdrawn, sleepy) is missed in ~75% of cases without screening — and carries higher mortality than hyperactive.

Find Trigger

Search for "DELIRIUM(S)"

Drugs · Electrolytes · Lack of drugs (withdrawal) · Infection · Reduced sensory input · Intracranial · Urinary retention & constipation · Myocardial / pulmonary · Sleep disruption / pain.

Prevent

Multicomponent care (HELP / ABCDEF)

Reorient, mobilize early, hydrate, treat pain, restore hearing aids + glasses, sleep hygiene (lights down, noise reduction, melatonin), avoid constipation/retention, deprescribe deliriogenic drugs (anticholinergics, benzos, opioids, steroids).

Avoid

No reflex antipsychotic

SCCM PADIS 2025: cannot recommend antipsychotics over usual care for ICU delirium — they don't reduce duration or mortality. Use only for dangerous distress at lowest effective dose. Haloperidol 0.5–2 mg PO/IM/IV q4h PRN; quetiapine 12.5–50 mg PO BID.

Exception

Benzodiazepines have lanes

Use benzos only for: alcohol/benzo withdrawal (CIWA-driven), seizures, catatonia (lorazepam challenge 1–2 mg IV), specific toxidromes (sympathomimetic, serotonin syndrome). Otherwise they worsen delirium and respiratory depression risk.

ICU 2025

Light sedation + dex over propofol

SCCM PADIS 2025 conditional recs: dexmedetomidine over propofol when delirium reduction is a priority · enhanced mobilization over usual care · melatonin for sleep · target light sedation (RASS −2 to 0). Insufficient evidence for benzos in anxiety.

Diagnostics · Pattern-Targeted

Target the Workup to the Pattern

AMS workups are broad but not random. Let physiology, risk factors, and exam findings drive the testing tree. Per ACR Appropriateness Criteria 2024, imaging is risk-guided, not reflexive.

CORE LABS

The first round

Glucose (POC), electrolytes (Na, K, Ca, Mg, PO₄), BUN/Cr, LFTs, CBC, VBG/ABG (if vent or acid-base concern), lactate (if sepsis/shock), ammonia (cirrhosis), CK (if rhabdo suspected), TSH (if elderly/euvolemic), pregnancy test, troponin (if elderly).

Glucose first, always
TOXICOLOGY

Targeted > broad

Acetaminophen + salicylate levels in every overdose (silent killers). Ethanol level. Targeted drug levels (lithium, valproate, digoxin) by history. Osmolar gap if methanol/EG suspected. ECG (QT, QRS). Tox screen has poor sensitivity for synthetic drugs and changes management rarely.

APAP + ASA always
IMAGING

NCCT for the right reasons

ACR 2024: focal deficit, severe headache, head trauma, anticoagulation, papilledema, post-seizure with persistent AMS, immunocompromised, suspected mass/bleed/CVST. MRI for posterior fossa, encephalitis, cerebellitis, ADEM, subtle bleed, autoimmune encephalitis. CTV/MRV for cerebral venous thrombosis.

Risk-guided, not reflex
CNS INFECTION

LP — but image first when needed

Indicators: fever + meningismus, immunosuppression, seizure, severe headache, rash. CT before LP if focal deficits, papilledema, GCS <10, immunocompromise, recent seizure. Empiric Abx (vanc + ceftriaxone ± ampicillin if >50 yr) + acyclovir 10 mg/kg q8h if HSV encephalitis suspected — don't wait for results.

Antibiotics < 1 h
EEG

For the invisible seizures

Continuous EEG (cEEG) for: persistent unexplained AMS post-seizure, fluctuating coma, subtle motor signs, cortical hemorrhage with AMS out of proportion, autoimmune encephalitis, ICU patients with unexplained obtundation. NCSE accounts for ~5–10% of unexplained AMS.

cEEG ≥24h ideal
SPECIALTY

When to escalate

Neurology: stroke, NCSE, encephalitis, autoimmune, refractory AMS. Toxicology: overdose, antidote selection, smoke inhalation, metals. Psychiatry: after medical screening per ACEP. Endocrine: thyroid storm, myxedema, adrenal crisis. Hepatology: HE refractory or atypical. ID: meningitis/encephalitis, immunocompromise.

Multidisciplinary
Case Cockpit · Convert Bedside Data → Action

Scenario-Based Clinical Reasoning

Pick a presentation. The pathway updates with the immediate moves, the dose, the trap, and the do-not-miss pearl. Pillars on the right are the constants in every plan.

Opioid Overdose Pattern

  • Airway and ventilation FIRST. BVM with 100% O₂, sniffing position, suction. Capnography if available. Don't bolus naloxone before oxygenating.
  • Naloxone 0.04–0.4 mg IV titrate to RR >10/adequate ventilation — overshoot precipitates withdrawal in chronic users. IN: 4 mg. IM: 0.4–2 mg.
  • Half-life ~30 min — observe ≥2 h. Long-acting opioids (methadone, fentanyl patches) often need infusion: 2/3 of wake-up dose per hour.
  • Check for co-ingestions (APAP + ASA in every overdose), aspiration, hypoxic injury. ECG for QT/QRS. Linkage to harm reduction + buprenorphine + take-home naloxone.
  • Don't discharge same-encounter unless recovery sustained ≥2 h post-last-dose, no recurrent symptoms, intact mental status, safe disposition with caregiver.
Identify

Glucose · O₂ · Toxin · Trauma

POC glucose in <1 min. Pulse ox + RR. Pupils + skin + bowel + temp. Ask the family / bystanders before they leave.

Stabilize

Airway · Circulation · Antidote

GCS ≤8 = intubation discussion. Ventilate before naloxone for safety. D50W or thiamine in parallel — they're both cheap.

Localize

Diffuse vs Focal vs Toxic

Focal sign? → CT. Diffuse + fever? → think infection / sepsis. Specific toxidrome? → match pattern. AMS with no answer at 30 min? → continuous EEG, expand workup.

Disposition

Capacity · Safety · Cause known?

Don't discharge unresolved dangerous AMS. Capacity is decision-specific and often returns once cause is treated. ICU vs floor depends on monitoring needs and reversibility.

Systems · Safety · Capacity

Disposition Without Anchoring

AMS patients often can't advocate for themselves. Good care includes dignity, collateral history, defendable safety planning, and avoiding diagnostic anchors — "it's just dementia," "it's just psych," "they're always like this."

ACEP psych

No automatic battery

ACEP supports focused, risk-guided medical assessment for psychiatric presentations. Delirium, abnormal vitals, intoxication, new symptoms, age >55, or new psychosis → expanded workup. Otherwise, history + exam + targeted labs.

Capacity

Decision-specific, restorable

Four-prong test: understand the situation, appreciate consequences, reason, and communicate a choice (Appelbaum). Treat reversible AMS first — capacity often returns. Document each prong individually.

Sepsis

AMS = organ dysfunction

Surviving Sepsis 2021: hour-1 bundle includes lactate, blood cultures, broad-spectrum antibiotics, 30 mL/kg crystalloid for hypoperfusion or lactate ≥4, vasopressors for MAP <65. Reassess continuously — de-escalate if alternative diagnosis emerges.

Restraints

Least restrictive · documented

De-escalate first: dim lights, family at bedside, treat pain/hypoxia/withdrawal, sitter when safe. If physical or chemical restraints unavoidable: document imminent danger, alternatives tried, monitoring, reassessment. Joint Commission requires reassessment q1–4h.

Geriatrics

Older adults are high-risk

~30% of hospitalized older adults develop delirium. Hypoactive delirium, occult infection (especially UTI without dysuria), polypharmacy, dehydration, urinary retention, constipation, sensory deprivation are common traps. Beers Criteria: avoid anticholinergics, benzos, opioids when possible.

Discharge

Baseline + supervision

Don't discharge unresolved dangerous AMS without: clear cause identified, safe supervision, capacity restored, medication reconciliation, follow-up arranged, family/caregiver education. If any element missing → admit or observe. Document the rationale.

Active Recall · 12 Questions

Board-Style Micro Quiz

Twelve high-yield questions across recognition, scoring tools, toxidromes, antidotes, status epilepticus, delirium, severe hyponatremia, and ACEP medical clearance. Streak counter, badges, immediate teaching pearl after every answer.

Question 1 of 12
Streak: 0

What is the single most important bedside test in nearly every undifferentiated AMS patient?

Evidence Base · Verified April 2026

Guidelines, Trials & Pivotal Evidence

AMS has no single master guideline; this tool integrates high-yield guidance across emergency, ICU, geriatrics, toxicology, endocrine, hepatology, and imaging domains. Always defer to current institutional protocols and the latest published versions before clinical decisions.

SCCM PADIS 2025 Focused Update Lewis et al. Crit Care Med 2025;53:e711–e727. Updated ICU guidance: anxiety (new topic), agitation/sedation (dex over propofol when delirium reduction is priority), delirium, immobility (enhanced mobilization), sleep (melatonin). Read source
NICE CG103 Delirium · 2023 Update UK NICE delirium guideline — prevention, diagnosis, management in hospital and long-term care. 2023 update added 4AT and CAM as preferred screening tools. Read source
ACR Appropriateness Criteria · AMS 2024 Imaging guidance for altered mental status, coma, delirium, and psychosis. Risk-guided NCCT/MRI/CTA selection rather than reflexive imaging for all. Read source
ACEP Adult Psychiatric Emergencies · 2023 Policy statement supporting focused medical screening based on H&P; rejects automatic perfunctory testing for all psychiatric presentations. Read source
ACEP Seizure Clinical Policy · 2024 ED management of adult seizure presentations. Relevant to postictal AMS, NCSE concern, and disposition decisions. Read source
ESETT Trial · NEJM 2019 Kapur et al. Established equivalence of levetiracetam, fosphenytoin, and valproate as second-line therapy in benzo-refractory convulsive status epilepticus (~46% response each at 60 min). Read source
RAMPART Trial · NEJM 2012 Silbergleit et al. IM midazolam non-inferior to IV lorazepam in pre-hospital convulsive SE. Foundation for IM benzo when no IV access. Read source
Surviving Sepsis Campaign · 2021 Evans et al. Hour-1 bundle: lactate, blood cultures, broad-spectrum antibiotics, 30 mL/kg crystalloid for hypoperfusion, vasopressors for MAP <65. Continuous reassessment and antibiotic de-escalation. Read source
European Hyponatremia Guideline · 2014 Spasovski et al. Eur J Endocrinol. 3% saline 100–150 mL bolus for severe symptomatic hyponatremia. Max correction 8–10 mEq/L per 24h to prevent osmotic demyelination. Read source
EFNS Wernicke Encephalopathy Galvin et al. Eur J Neurol 2010. Caine criteria + parenteral thiamine 500 mg IV TID × 3 days for established Wernicke; 100–200 mg IV/IM for prophylaxis. Treat empirically — risk-benefit overwhelmingly favors treatment. Read source
AASLD Hepatic Encephalopathy · 2014 Vilstrup et al. Hepatology 2014. West Haven criteria, precipitant identification (infection, GI bleed, constipation, sedatives, electrolytes), lactulose first-line, rifaximin for prevention/refractory. Read source
4AT Validation · MacLullich Shenkin et al. BMC Med 2019. Pooled sensitivity ~88%, specificity ~88% across multiple validation studies. Endorsed by NICE 2023 and Scottish Delirium Association as primary delirium screening tool. Read source
FOUR Score Validation · Wijdicks Wijdicks et al. Ann Neurol 2005;58:585–593. Four-component coma scale (eye, motor, brainstem, respiration) — testable in intubated patients, captures brainstem function, predicts in-hospital mortality. Read source
ADA Standards of Care · 2026 Current diabetes care standards including hypoglycemia recognition (Level 1 <70, Level 2 <54, Level 3 = severe with cognitive change), prevention, glucagon for severe events. Read source
SAMHSA Overdose Prevention Opioid overdose recognition and response, naloxone/nalmefene dosing, post-revival observation, treatment linkage and harm reduction strategies for opioid use disorder. Read source
ASAM Alcohol Withdrawal · 2020 The ASAM Clinical Practice Guideline on Alcohol Withdrawal Management. CIWA-Ar scoring (≥10 = treat), benzodiazepines first-line (front-loaded vs symptom-triggered), management of alcohol withdrawal delirium (DTs). Read source