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USMLE Step 3 - Emergency Medicine & Critical Care: High-Yield Must-Knows

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1. SEPSIS & SEPTIC SHOCK

• Sepsis: suspected/confirmed infection + SOFA score increase ≥2 from baseline
• Septic shock: sepsis + vasopressors needed to maintain MAP >65 mmHg + lactate >2 mmol/L despite fluid resuscitation
• qSOFA (bedside screen): RR ≥22, GCS <15, SBP ≤100 - score ≥2 = poor prognosis

• Every 1-hour delay in antibiotics in septic shock = ~7-8% increase in mortality
• If infection uncertain and no shock: reassess; if no alternative dx within 3 h, start antibiotics
• Source control is mandatory (drain abscess, remove infected line, etc.)

• Norepinephrine is first-line for septic shock - start at 3-5 mcg/min
• Vasopressin: second-line add-on when NE dose is high; does not outperform NE alone but spares NE dose
• Dopamine: more side effects vs. NE; generally avoided
• Stress-dose hydrocortisone (200 mg/day) if refractory to 2+ vasopressors

• Unknown source, no Pseudomonas risk: ceftriaxone or cefotaxime
• Pseudomonas risk (hospital-acquired, neutropenic, structural lung disease): cefepime, pip-tazo, or carbapenem
• Double gram-negative coverage if prior resistant organisms
• Add vancomycin if MRSA risk (catheter-related, prior MRSA, skin/soft tissue)
• Intra-abdominal/anaerobic coverage: metronidazole or pip-tazo

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2. SHOCK - TYPES & HEMODYNAMIC PATTERNS

• Epinephrine IM (0.3-0.5 mg into anterolateral thigh) is first-line - give immediately
• Diphenhydramine + steroids are adjuncts, NOT first-line
• Airway is the priority - early intubation if laryngeal edema
• If hypotension persists: IV fluids + epinephrine infusion

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3. CARDIAC ARREST & ACLS

• CPR + defibrillate immediately (200 J biphasic)
• Epinephrine 1 mg IV/IO every 3-5 min
• Amiodarone 300 mg IV (or lidocaine) after 3rd shock
• Continue CPR 2 minutes between shocks

• CPR + epinephrine 1 mg every 3-5 min
• Treat reversible causes (H's and T's)

• Hypovolemia, Hypoxia, H⁺ (acidosis), Hypo/Hyperkalemia, Hypothermia
• Tension pneumothorax, Tamponade, Toxins, Thrombosis (PE or MI)

• Targeted temperature management (TTM): 32-36°C for 24 h (comatose patients)
• 12-lead ECG: rule out STEMI - emergent cath if indicated
• Avoid hyperoxia: titrate O₂ to SpO₂ 94-98%
• Avoid hypotension: MAP ≥65 mmHg
• Avoid hyperventilation: target PaCO₂ 35-45 mmHg

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4. ACUTE MI

• Door-to-balloon time: ≤90 min (PCI preferred)
• PCI not available: thrombolytics if no contraindications, door-to-needle ≤30 min
• Aspirin 325 mg + P2Y12 inhibitor (ticagrelor or clopidogrel) immediately
• Anticoagulation: UFH, enoxaparin, or bivalirudin

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5. PULMONARY EMBOLISM

• Massive PE: hemodynamic instability (SBP <90, shock) - systemic thrombolytics (tPA) or embolectomy
• Submassive PE: RV dysfunction on echo/CT but hemodynamically stable - monitor closely, thrombolytics if deteriorating
• Low-risk PE: outpatient anticoagulation (NOAC preferred)

• Anticoagulate immediately (don't wait for imaging if high clinical suspicion)
• NOACs (rivaroxaban, apixaban) preferred over warfarin for most patients
• UFH if unstable (prior to possible thrombolysis/embolectomy)
• Massive PE: alteplase (tPA) 100 mg IV over 2 h - main contraindication = recent surgery/stroke/active bleeding

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6. ARDS (Acute Respiratory Distress Syndrome)

• Acute onset within 1 week of clinical insult
• Bilateral infiltrates on CXR not explained by effusion/collapse/nodules
• PaO₂/FiO₂ ratio: Mild 200-300, Moderate 100-200, Severe <100 (all on PEEP ≥5)
• Not fully explained by cardiac failure/fluid overload

• TV: 4-6 mL/kg ideal body weight
• Plateau pressure: ≤30 cmH₂O
• PEEP: titrate to oxygenation (higher PEEP for more severe ARDS)
• Prone positioning for PaO₂/FiO₂ <150: improves mortality (16-hour sessions)
• Neuromuscular blockade (cisatracurium) for severe ARDS in early phase
• Conservative fluid strategy after initial resuscitation

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7. TRAUMA (Primary & Secondary Survey)

• Airway with C-spine protection
• Breathing - assess, needle decompression for tension PTX, chest seal for open PTX
• Circulation - control hemorrhage, 2 large-bore IVs, massive transfusion protocol (1:1:1 ratio pRBC:FFP:platelets)
• Disability - GCS, pupils
• Exposure - full body exam, prevent hypothermia

• Positive FAST + hemodynamic instability = emergent laparotomy
• Stable patient with abdominal trauma = CT abdomen/pelvis

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8. TOXICOLOGY (High-Yield Antidotes)

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9. ENVIRONMENTAL EMERGENCIES

• Core temp >40°C (104°F) + CNS dysfunction (altered mental status, seizures)
• Classic: elderly/no sweating; Exertional: athletes/sweating present
• Rapid cooling is the treatment - ice water immersion (fastest), evaporative cooling
• Avoid antipyretics (useless - not fever, it's failed thermoregulation)

• Mild 32-35°C: passive rewarming (blankets)
• Moderate 28-32°C: active external rewarming
• Severe <28°C: active core rewarming (warm IVF, warmed humidified O₂, bladder lavage)
• Cardiac arrest from hypothermia: "not dead until warm and dead" - ECMO/CPB if available

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10. AIRWAY MANAGEMENT & VENTILATOR PEARLS

• Pre-oxygenate 100% O₂ for 3-5 min
• Sedation: etomidate (most common), ketamine (preferred in hypotension/bronchospasm), propofol (hypotension risk)
• Paralytic: succinylcholine (fastest onset, avoid in hyperkalemia, burns >48h, crush injury, neuromuscular disease) vs. rocuronium (preferred when succinylcholine contraindicated)

• Mode: Volume-assist control most common in ICU
• TV: 6-8 mL/kg IBW (4-6 for ARDS)
• RR: 12-16/min
• FiO₂: titrate to SpO₂ 92-96%
• PEEP: 5 cmH₂O starting; higher for ARDS

• Auto-PEEP/air trapping (COPD/asthma): decrease RR, increase expiratory time
• Ventilator-associated pneumonia (VAP): HOB elevation 30-45°, oral chlorhexidine, daily sedation vacations, ventilator weaning protocols

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11. CRITICAL CARE PEARLS (Bread-and-Butter ICU)

• RIFLE/KDIGO criteria: Cr increase ≥1.5x baseline or UO <0.5 mL/kg/hr for 6 h
• Avoid nephrotoxins (NSAIDs, aminoglycosides, contrast when possible)
• Indications for emergent dialysis: Acidosis (pH <7.1), Electrolytes (K >6.5), Intoxication, Overload (pulmonary edema), Uremia (encephalopathy, pericarditis)

• Analgesia-first approach (pain before sedation)
• Light sedation target (RASS -1 to 0) better outcomes than deep sedation
• Daily sedation interruptions + spontaneous breathing trials (SBT) - ventilator liberation
• Delirium: prevent with ABCDEF bundle; haloperidol or quetiapine for agitated delirium

• Pharmacologic (LMWH or UFH) + mechanical (SCDs) for all ICU patients unless contraindicated
• Active hemorrhage, recent neurosurgery: mechanical only until safe to start pharma

• Target glucose 140-180 mg/dL (tight control 80-110 increases hypoglycemia risk and mortality)

• Indicated: mechanical ventilation >48h, coagulopathy, burns (Curling's ulcer), brain injury (Cushing's ulcer), high-dose steroids
• PPI or H2-blocker

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12. CCS (Computer-Based Case Simulation) STRATEGY

1. Stabilize first - always address ABCs before ordering diagnostic tests
2. Order empirically - in a sick patient, treat while you work up (e.g., give antibiotics before all cultures back)
3. Advance time appropriately - don't over-advance when patient is unstable
4. Admit to the right level of care - ICU for ventilated, septic shock, or hemodynamically unstable patients
5. Consultations: Surgery for abdominal trauma; Nephrology for AKI needing dialysis; Cardiology for STEMI
6. Disposition: Address discharge planning, follow-up, and education before closing the case

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Quick-Hit Reminders

• Troponin: best for ACS but rises 3-6 hours after injury; serial testing at 0 and 3-6 hours
• BNP >100: heart failure; used to differentiate cardiac vs. pulmonary dyspnea
• Tension pneumothorax: tracheal deviation away from affected side, absent breath sounds, JVD, hypotension - needle decompression at 2nd ICS MCL immediately, then chest tube
• Cardiac tamponade: Beck's triad (hypotension, JVD, muffled heart sounds); pulsus paradoxus >10 mmHg; pericardiocentesis
• Aortic dissection: tearing chest pain radiating to back, unequal BPs in arms; CT angiography; Type A (ascending) = surgical emergency; Type B (descending) = medical management (labetalol to control BP/HR)
• Epiglottitis: drooling, "hot potato" voice, tripod position; do NOT examine airway without controlled intubation setup; racemic epinephrine if stridor

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USMLE Step 3 CCS - High-Yield Cases Master Guide

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How CCS Is Scored (Know This First)

• 13-14 cases on Day 2, each 10 or 20 minutes of real clock time
• Each case = ~3% of your total score - you cannot afford to blank one
• Scored across 4 domains: History/Physical, Diagnostics, Therapeutics, Monitoring/Preventive Care
• You lose points for: wrong location, missing monitoring, failing to reassess, not counseling at discharge
• Never jump time by a fixed interval - always advance to "next available result"
• At the 2-minute end screen: add monitoring, counseling, follow-up orders - don't delete active orders

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Universal CCS Framework (Apply to Every Case)

1. STABILIZE   → ABCs, O2, IV access, vitals, pulse ox (order manually!), cardiac monitor
2. LOCATE      → Set correct care location immediately (ER, floor, ICU, clinic, home)
3. WORK UP     → Targeted H&P + core labs: CBC, BMP, UA ± imaging ± EKG
4. TREAT       → Start empiric treatment for the most likely diagnosis
5. MONITOR     → Vitals frequency, repeat labs, I/O, reassess symptoms
6. REASSESS    → Advance to next result; adjust treatment; escalate or de-escalate care
7. DISPOSITION → Admit, transfer, or discharge with follow-up + patient counseling

• Vital signs (specify frequency: q1h if unstable, q4-8h if stable)
• Pulse oximetry (not in default vitals - must order!)
• Continuous cardiac monitoring (if any chest/cardiac/critical complaint)
• IV access + IV fluids (if sick)
• NPO (if surgery possible or patient unstable)

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HIGH-YIELD CASE 1: Acute MI / STEMI

1. O2 (if SpO2 <94%), IV access, cardiac monitor, pulse ox
2. Aspirin 325 mg PO - give immediately
3. EKG stat (confirm STEMI)
4. Nitroglycerin SL (if SBP >90, no RV infarct)
5. Morphine (pain, but use judiciously)
6. Heparin IV (UFH bolus + drip)
7. P2Y12 inhibitor: clopidogrel or ticagrelor
8. Beta-blocker PO (if no HF, no bradycardia, no shock)
9. CBC, BMP, troponin, PT/PTT, lipid panel, CXR
10. Cardiology consult (for cath/PCI)

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HIGH-YIELD CASE 2: NSTEMI / Unstable Angina

• No emergent PCI - risk stratify with TIMI score
• High-risk NSTEMI: cardiology consult, cath within 24-48h
• Add atorvastatin (high-intensity)
• No thrombolytics

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HIGH-YIELD CASE 3: Sepsis / Septic Shock

1. O2, IV access (2 large-bore), cardiac monitor, pulse ox, foley catheter (to monitor UO)
2. Blood cultures x2 (before antibiotics)
3. Lactate level, CBC, BMP, UA with culture
4. IV crystalloid 30 mL/kg NS or LR (if hypotensive)
5. Broad-spectrum antibiotics within 1 hour: vancomycin + piperacillin-tazobactam (or cefepime)
6. Norepinephrine IV if MAP <65 despite 2L fluids
7. CXR (look for source)
8. Procalcitonin

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HIGH-YIELD CASE 4: DKA (Diabetic Ketoacidosis)

1. O2, IV access, cardiac monitor (hyperkalemia can cause arrythmias)
2. IV NS 1L bolus (aggressive fluids)
3. BMP stat, ABG, serum ketones, CBC, UA, phosphate, magnesium
4. EKG (r/o MI as precipitant; check for peaked T waves)
5. Check K+ FIRST before starting insulin - if K <3.5, replace K before insulin
6. Regular insulin 0.1 units/kg IV bolus → 0.1 units/kg/hr drip
7. Potassium replacement (even if K is normal - insulin will drop it)
8. Switch IV fluids to D5 ½NS when glucose reaches 200-250 mg/dL
9. Identify precipitant: infection? Missed insulin?

• Glucose <200
• Bicarb ≥15
• Anion gap closed (<12)
• pH >7.3

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HIGH-YIELD CASE 5: Pulmonary Embolism

1. O2, IV access, pulse ox, cardiac monitor
2. CBC, BMP, D-dimer, troponin, BNP
3. EKG (S1Q3T3, sinus tach, new RBBB)
4. CT pulmonary angiography (if stable + normal Cr)
5. Start anticoagulation - do NOT wait for CT if high clinical suspicion
   • Stable: enoxaparin or rivaroxaban (loading dose)
   • Massive PE with shock: UFH IV drip (easier to reverse)
6. Echo (check for RV strain - submassive PE)
7. If massive PE + hemodynamic instability: tPA (alteplase) 100 mg IV over 2h
8. Bilateral lower extremity Doppler ultrasound

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HIGH-YIELD CASE 6: Stroke (Ischemic)

1. O2, IV access, pulse ox, cardiac monitor
2. Non-contrast CT head STAT (r/o hemorrhage before tPA)
3. Finger-stick glucose (r/o hypoglycemia mimicking stroke)
4. CBC, BMP, PT/PTT/INR, type & screen
5. EKG (r/o afib as source)
6. tPA (alteplase) 0.9 mg/kg IV if:
   • Within 4.5 hours of symptom onset
   • No hemorrhage on CT
   • No contraindications (recent surgery, anticoagulants, BP >185/110)
7. NPO (aspiration risk)
8. Neurology consult, neurosurgery if hemorrhagic
9. Aspirin only if NOT giving tPA (wait 24h after tPA)
10. MRI brain (after CT to define infarct)

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HIGH-YIELD CASE 7: Asthma Exacerbation / Status Asthmaticus

1. O2 (target SpO2 >92%), pulse ox, IV access
2. Albuterol nebulizer (short-acting beta-agonist) q20min x3 (back-to-back in severe)
3. Ipratropium bromide (anticholinergic) - add in moderate-severe
4. Systemic steroids: methylprednisolone IV or prednisone PO 40-80 mg
5. ABG (if severe, pH <7.35, PCO2 rising = impending respiratory failure)
6. CXR (r/o pneumothorax, pneumonia)
7. CBC, BMP
8. Magnesium sulfate 2g IV (if not responding to initial bronchodilators)
9. Heliox (He-O2 mixture) if refractory

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HIGH-YIELD CASE 8: COPD Exacerbation

• Albuterol + ipratropium nebs
• Systemic steroids (prednisone 40 mg x5 days)
• Antibiotics: azithromycin or doxycycline (if purulent sputum/fever)
• NIV (BiPAP) before intubating - significantly reduces intubation rates
• Target SpO2 88-92% (not 100% - hypercapnic drive concern)
• Sputum culture if hospitalized

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HIGH-YIELD CASE 9: Chest Pain - Aortic Dissection

1. O2, IV x2, monitor, pulse ox
2. CXR (widened mediastinum)
3. CT angiography chest (gold standard)
4. Labetalol IV immediately (lower HR <60 first, then SBP <120) - never give vasodilator alone without beta-blocker (reflex tachycardia worsens dissection)
5. CBC, BMP, troponin (r/o MI), type & screen, coags
6. NPO
7. Cardiothoracic surgery consult

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HIGH-YIELD CASE 10: Acute Abdomen / Appendicitis

1. NPO, IV access, IV fluids, vitals
2. CBC (leukocytosis), BMP, UA (r/o UTI/renal stone), LFTs, lipase
3. Beta-HCG in women of reproductive age (r/o ectopic)
4. CT abdomen/pelvis with contrast (most sensitive for appendicitis)
5. Ultrasound first in pregnant women and children
6. IV cefazolin/metronidazole (or pip-tazo) before surgery
7. Surgery consult (after imaging, not before in uncomplicated cases)
8. Pain control: morphine or ketorolac (giving analgesics does NOT mask surgical abdomen - give pain meds)
9. Foley catheter

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HIGH-YIELD CASE 11: GI Bleed

1. 2 large-bore IVs, type & crossmatch, transfuse if Hgb <7 (or <8 if cardiac disease)
2. IV PPI (pantoprazole 80 mg bolus → 8 mg/hr drip)
3. Octreotide if variceal bleed suspected (cirrhosis, spider angiomata)
4. NPO
5. GI consult for EGD within 24h (12h if actively bleeding)
6. Correct coagulopathy: FFP if INR >1.5, platelets if <50K

1. Same resuscitation
2. Colonoscopy after prep
3. Tagged RBC scan or angiography if bleeding too rapid for colonoscopy

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HIGH-YIELD CASE 12: DKA vs HHS - Know the Difference

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HIGH-YIELD CASE 13: Meningitis

1. O2, IV access, monitor
2. Blood cultures x2 stat
3. Ceftriaxone 2g IV + vancomycin IV immediately
4. Dexamethasone 0.15 mg/kg IV (give before or with first antibiotic dose - reduces hearing loss in S. pneumoniae)
5. Acyclovir if HSV encephalitis suspected (altered mental status + temporal lobe involvement)
6. CT head before LP only if: focal neuro deficits, papilledema, immunocompromised, or seizure
7. LP: opening pressure, cell count, glucose, protein, Gram stain, culture
8. Contact/droplet precautions (N. meningitidis)
9. CBC, BMP, blood culture

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HIGH-YIELD CASE 14: Eclampsia / Pre-Eclampsia

1. O2, IV access, monitor, pulse ox, fetal monitoring
2. Magnesium sulfate IV (4-6g bolus → 1-2g/hr) - prevents/treats seizures
3. Hydralazine or labetalol IV (if BP >160/110) - do NOT use ACEi/ARBs in pregnancy
4. CBC, BMP, LFTs, uric acid, urinalysis, 24h urine protein, coags
5. MgSO4 toxicity monitoring: DTRs q1h (loss = early toxicity), UO, respiratory rate
6. Antidote for MgSO4 toxicity: calcium gluconate at bedside
7. OB/MFM consult immediately
8. Definitive treatment = delivery (timing depends on gestational age and severity)

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HIGH-YIELD CASE 15: Pediatric Cases

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CCS End-of-Case Checklist (2-Minute Window)

• Vitals ordered at appropriate frequency
• Monitoring labs scheduled (repeat BMP, CBC, cultures)
• Correct care location confirmed
• Relevant consults placed
• Patient counseling ordered (smoking cessation, dietary changes, medication instructions)
• Follow-up appointment scheduled
• DVT prophylaxis ordered if inpatient (LMWH + SCDs)
• Stress ulcer prophylaxis if on vent or ICU >48h
• VTE prophylaxis for surgical patients
• Post-procedure/discharge education ordered

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Common Pitfalls That Cost Points

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USMLE Step 3 CCS - Fully Simulated Walk-Throughs

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CASE 1: SEPSIS / SEPTIC SHOCK

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Opening Vignette

68-year-old man with DM and HTN brought by family for confusion and fever. He has had dysuria and flank pain for 2 days. He looks ill. Not on any antibiotics.

Vitals: T 39.4°C, HR 118, BP 84/52, RR 24, SpO2 94% on room air

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PHASE 1 - Real-time minutes 0-2 (Stabilize NOW)

Your brain: BP 84/52 = shock. Source = likely urosepsis. Clock is running. Do not stall.

✅ Vital signs every 1 hour
✅ Pulse oximetry continuous          ← must order manually
✅ Continuous cardiac monitoring
✅ O2 via nasal cannula at 2-4 L/min
✅ IV access x2 large bore
✅ 0.9% normal saline 1000 mL IV bolus (x2 = 2L, repeat again to reach 30 mL/kg)
✅ Foley catheter (measure urine output)
✅ Blood cultures x2 (peripheral)     ← MUST be before antibiotics
✅ Urinalysis with culture
✅ CBC with differential
✅ Basic metabolic panel
✅ Lactate level STAT
✅ Procalcitonin
✅ Chest X-ray portable
✅ Physical examination

Advance to: Next available result

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PHASE 2 - Results Return (simulated ~30 min later)

Labs: WBC 18.2 (85% PMNs), Hgb 11, Plt 140. Na 134, K 3.8, BUN 38, Cr 1.6, Glucose 210. Lactate 4.2 mmol/L. UA: pyuria, bacteriuria, nitrites positive.

BP now: 78/48 despite 2L NS. MAP = 58 mmHg (still <65 despite fluids)

CXR: No infiltrate. No effusion.

Your brain: Septic shock confirmed. MAP <65 despite fluid. Start vasopressor. Antibiotics NOW - you are already past the 1-hour mark.

✅ Norepinephrine 0.1 mcg/kg/min IV (titrate to MAP >65)
✅ Vancomycin 25-30 mg/kg IV                    ← MRSA/gram-positive coverage
✅ Piperacillin-tazobactam 3.375g IV q6h        ← gram-negative/broad coverage
   (or cefepime 2g IV q8h)
✅ Repeat lactate in 2 hours
✅ BMP every 4 hours
✅ I/O strict (target UO >0.5 mL/kg/hr)
✅ Urology consult (source = urinary tract)
✅ Transfer to ICU

Advance to: Next available result

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PHASE 3 - Reassessment (~2 hours simulated)

BP 102/64 (MAP 77) on norepinephrine 0.08 mcg/kg/min. HR 98. UO 45 mL/hr. Lactate now 1.8 mmol/L (improving).

Blood cultures: Gram-negative rods (final sensitivities pending).

UA culture: E. coli (preliminary).

Your brain: Responding. Norepinephrine working. Source confirmed = E. coli UTI/urosepsis. Antibiotics are appropriate.

✅ Continue norepinephrine (titrate down as tolerated)
✅ Continue piperacillin-tazobactam (covers E. coli)
✅ Discontinue vancomycin (gram-positive not needed - de-escalate)
✅ Repeat BMP in AM
✅ Repeat lactate in 4 hours
✅ Renal ultrasound (r/o obstructive uropathy - hydronephrosis)
✅ Nutrition consult (ICU patient)
✅ DVT prophylaxis: enoxaparin 40 mg SQ daily
✅ Stress ulcer prophylaxis: pantoprazole 40 mg IV daily

Advance to: Next available result

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PHASE 4 - Day 2 Simulated

Patient alert, oriented. BP 118/72 off vasopressors. HR 84. UO adequate. Lactate 1.2. Creatinine improving (1.1). Renal US: mild right hydronephrosis. Cultures: E. coli, sensitive to ceftriaxone.

Your brain: De-escalate antibiotics (narrowest effective spectrum). Arrange urology follow-up for hydronephrosis.

✅ Discontinue piperacillin-tazobactam
✅ Ceftriaxone 1g IV daily (de-escalated per sensitivities)
✅ Transfer to floor (out of ICU)
✅ Urology follow-up for hydronephrosis
✅ Plan for PO antibiotics on discharge

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END SCREEN (2-minute window) - Don't skip this

✅ Ciprofloxacin 500 mg PO BID x 14 days (discharge antibiotic)
✅ Follow-up with PCP in 1 week
✅ Follow-up with urology in 2-4 weeks
✅ Counsel: medication adherence, complete antibiotic course
✅ Counsel: diabetic management (glucose was 210 - address outpatient)
✅ Vitals on discharge

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Scoring Points Summary - Sepsis

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CASE 2: ACUTE MI / STEMI

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Opening Vignette

58-year-old man with hypertension and hyperlipidemia presents with 45 minutes of crushing substernal chest pain radiating to his left arm, associated with diaphoresis and nausea. He takes lisinopril and atorvastatin.

Vitals: T 37.0°C, HR 96, BP 154/88, RR 18, SpO2 97% on room air

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PHASE 1 - First 2 minutes (Stabilize + Diagnose fast)

Your brain: Classic STEMI presentation. Time = muscle. EKG is the FIRST diagnostic step. Do not delay.

✅ EKG 12-lead STAT                   ← most important first order
✅ Continuous cardiac monitoring
✅ Pulse oximetry continuous
✅ IV access x2
✅ Aspirin 325 mg PO (chew)           ← give immediately
✅ Nitroglycerin 0.4 mg SL (can repeat x3 if SBP >90)
✅ Morphine 2-4 mg IV (if pain not controlled with NTG)
✅ O2 only if SpO2 <94% (do NOT routinely give O2 if sat normal)
✅ Physical examination
✅ CBC, BMP, troponin I, PT/PTT/INR
✅ Lipid panel
✅ CXR portable

Advance to: Next available result

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PHASE 2 - EKG and initial labs return (< 10 min simulated)

EKG: ST elevation 3-4 mm in leads II, III, aVF. Reciprocal changes in I, aVL.

= Inferior STEMI (RCA territory)

Troponin I: 2.8 ng/mL (elevated). WBC 9.2, Hgb 14. BMP normal. INR 1.0. CXR: mild cardiomegaly, no pulmonary edema.

Your brain: Confirmed STEMI. Inferior MI - check for RV involvement (do right-sided leads). Activate the cath lab NOW.

✅ Right-sided EKG (check V4R)        ← mandatory in inferior STEMI
✅ Heparin UFH IV bolus 60 units/kg → 12 units/kg/hr drip
✅ Ticagrelor 180 mg PO loading dose  ← P2Y12 inhibitor (preferred over clopidogrel for STEMI)
   (or clopidogrel 600 mg PO if ticagrelor unavailable)
✅ Atorvastatin 80 mg PO (high-intensity statin)
✅ Cardiology consult STAT - activate cath lab
✅ Troponin repeat in 6 hours
✅ Transfer to cath lab / CCU
✅ NPO (may need procedure)

Advance to: Next available result

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PHASE 3 - Results + Cath Lab

Right-sided EKG: No ST elevation in V4R (no RV infarct - safe to use nitrates).

Patient reports pain is 4/10 (improved from 9/10 with aspirin + nitrates).

Cardiology team at bedside: recommends primary PCI. Door-to-balloon time goal: 90 minutes.

Your brain: PCI is the plan. Ensure anticoagulation is on board. Beta-blocker if hemodynamically appropriate.

✅ Metoprolol tartrate 25 mg PO       ← start if HR >60, SBP >120, no HF/shock
✅ Confirm heparin drip running
✅ Nothing to change - transfer to cath lab
✅ Vitals every 30 min

Advance to: Next available result

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PHASE 4 - Post-PCI (back from cath lab)

Patient returns from cath lab. Successful PCI with stent placement to RCA. Pain resolved. BP 128/78, HR 72. No bleeding at access site.

Troponin peak: 18.6 ng/mL. EKG: T-wave changes in II/III/aVF (reperfusion pattern).

Your brain: Successful reperfusion. Now optimize medical therapy and prevent complications.

✅ Admit to CCU
✅ Aspirin 81 mg PO daily (lifelong)
✅ Ticagrelor 90 mg PO BID x 12 months (dual antiplatelet therapy - DAPT)
✅ Continue atorvastatin 80 mg PO daily
✅ Metoprolol succinate (long-acting) daily
✅ Lisinopril (or ramipril) - start within 24h (cardioprotective, especially if EF reduced)
✅ Continuous telemetry
✅ Serial EKGs every 8 hours x 24h
✅ Echocardiogram (assess wall motion, EF)
✅ DVT prophylaxis (SCDs - patient already on anticoagulation)
✅ Vitals q4h
✅ Activity: bed rest x 12h then progressive ambulation
✅ Cardiac rehab referral

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END SCREEN (2-minute window)

✅ Discharge medications: aspirin 81 mg, ticagrelor 90 mg BID, metoprolol, lisinopril, atorvastatin 80 mg
✅ Counsel: no NSAIDs (interact with antiplatelet therapy and worsen cardiac outcomes)
✅ Counsel: smoking cessation
✅ Counsel: low-fat, low-sodium diet
✅ Counsel: no heavy lifting x 1 week (femoral access site)
✅ Follow-up with cardiology in 1-2 weeks
✅ Follow-up with PCP in 2-4 weeks
✅ Cardiac rehab referral

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Scoring Points Summary - STEMI

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CASE 3: DKA (Diabetic Ketoacidosis)

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Opening Vignette

24-year-old woman with Type 1 DM presents with 1 day of nausea, vomiting, and abdominal pain. She ran out of insulin 2 days ago. She is drowsy but arousable. Breath smells fruity.

Vitals: T 37.8°C, HR 122, BP 96/60, RR 28 (deep/labored), SpO2 98%

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PHASE 1 - First 2 minutes (Recognize + Act)

Your brain: Kussmaul breathing + fruity breath + Type 1 DM + missed insulin = DKA until proven otherwise. DO NOT start insulin yet. Check potassium first - insulin drives K into cells and can cause fatal arrhythmia if K is low.

✅ Vital signs every 1 hour
✅ Continuous cardiac monitoring       ← peaked T waves = hyperkalemia
✅ Pulse oximetry continuous
✅ IV access x2 large bore
✅ 0.9% normal saline 1L IV bolus NOW (10-20 mL/kg/hr)
✅ Physical examination
✅ BMP STAT                            ← need K+ before insulin
✅ CBC with differential
✅ Serum ketones (beta-hydroxybutyrate)
✅ ABG STAT                            ← pH, HCO3, PCO2
✅ Urinalysis
✅ Blood glucose finger-stick NOW
✅ Phosphate and magnesium levels
✅ EKG                                 ← check for hyperkalemia pattern
✅ Urine/blood cultures (r/o infectious trigger)

Advance to: Next available result

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PHASE 2 - Critical Labs Return (~15 min simulated)

Glucose: 480 mg/dL

BMP: Na 128, K 3.1, Cl 90, HCO3 8, BUN 22, Cr 1.1

Calculated anion gap: Na - (Cl + HCO3) = 128 - (90+8) = 30 (high, normal <12)

ABG: pH 7.14, PCO2 18, HCO3 8 (primary metabolic acidosis with respiratory compensation)

Serum ketones: Large

EKG: Sinus tachycardia, no peaked T waves

⚠️ K is 3.1 - DO NOT start insulin yet. Replace potassium first.

Your brain: Classic DKA. K is low (3.1). If you start insulin now, K will drop further → cardiac arrhythmia. Replace K first to >3.5, then start insulin. Also: fluids are the top priority in the first 1-2 hours.

✅ 0.9% NS continue at 500 mL/hr (aggressive rehydration x 2-4h)
✅ Potassium chloride 40 mEq IV in first liter of NS
   (do NOT start insulin until K >3.5 mEq/L)
✅ DO NOT order insulin yet
✅ Repeat BMP in 1 hour (recheck K before starting insulin)
✅ I/O strict
✅ NPO

Advance to: Next available result

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PHASE 3 - 1 Hour Later

Repeat K: 3.8 mEq/L (now safe to start insulin). Glucose 440. Repeat ABG: pH 7.19. Patient still drowsy but responding to voice.

Your brain: K now >3.5. START insulin now.

✅ Regular insulin 0.1 units/kg IV bolus (approximately 7 units for 70 kg patient)
✅ Regular insulin 0.1 units/kg/hr IV drip continuous
✅ Continue 0.9% NS at 250-500 mL/hr
✅ KCl 20-40 mEq in each liter of IV fluid (to keep K 4.0-5.0)
✅ Blood glucose every 1 hour
✅ BMP every 2-4 hours (monitor K, HCO3, anion gap)
✅ Do NOT give sodium bicarbonate (pH not <6.9)
✅ Admit to ICU

Target glucose drop: 50-100 mg/dL per hour. If dropping faster, slow insulin. If not dropping by 2 hours, double the rate.

Advance to: Next available result

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PHASE 4 - 4 Hours Later

Glucose: 230 mg/dL (approaching 250 threshold). K: 3.5. HCO3: 11. Anion gap: 22 (improving). pH: 7.24.

Your brain: Glucose near 250 - SWITCH IV FLUID to prevent hypoglycemia but keep insulin running to close the anion gap. DO NOT stop insulin - anion gap not yet closed.

✅ STOP 0.9% NS
✅ START D5 + 0.45% NS at 150-250 mL/hr   ← dextrose prevents hypoglycemia while insulin continues
✅ Continue insulin drip at same rate (or reduce to 0.02-0.05 units/kg/hr)
✅ Continue KCl in fluids
✅ Continue glucose checks every 1 hour
✅ Continue BMP every 4 hours

Advance to: Next available result

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PHASE 5 - Resolution (12 hours simulated)

Glucose: 165. K: 4.2. HCO3: 20. Anion gap: 11 (CLOSED). pH: 7.38.

Patient awake, alert, asking for food. No nausea. Vitals stable.

DKA resolution criteria - ALL must be met:

• Glucose <200 ✅
• Anion gap <12 ✅
• Bicarbonate ≥18 ✅
• pH >7.3 ✅

Your brain: DKA resolved. Time to transition to subcutaneous insulin. OVERLAP is mandatory - do NOT just stop the drip.

✅ Endocrinology consult
✅ Resume home diet (clear liquids → regular)
✅ Glargine (long-acting insulin) SQ dose NOW    ← give 2-4 hours BEFORE stopping drip
✅ STOP insulin drip 2-4 hours after glargine given
✅ Sliding scale regular insulin (correction doses with meals)
✅ Continue BMP daily
✅ Transfer to floor (out of ICU)
✅ Identify precipitant: ran out of insulin → counseling

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END SCREEN (2-minute window)

✅ Discharge with insulin pen (long-acting + short-acting)
✅ Counsel: never stop insulin even if not eating (adjust dose, never skip)
✅ Counsel: sick day rules (check glucose q2-4h when ill)
✅ Counsel: ketone testing when glucose >240
✅ Counsel: when to come to ED (glucose >300, vomiting, moderate-large ketones)
✅ Endocrinology follow-up in 1-2 weeks
✅ PCP follow-up in 1 week
✅ Diabetes education referral

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Scoring Points Summary - DKA

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The 3 Cases Side-by-Side: Fatal Mistakes to Avoid