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High-Yield Emergency Medicine Topics

1. Cardiovascular Emergencies

• ACS - STEMI vs NSTEMI, Killip classification, thrombolytics vs PCI
• Aortic dissection - Stanford/DeBakey classification, BP management
• Cardiac tamponade - Beck's triad, pulsus paradoxus, emergency pericardiocentesis
• Arrhythmias - AF, VT, VF, SVT - when to cardiovert vs defibrillate
• Heart failure - acute pulmonary edema management

2. Respiratory Emergencies

• Tension pneumothorax - needle decompression landmarks
• Status asthmaticus - stepwise management, MgSO4 dosing
• Pulmonary embolism - Wells score, PERC rule, massive PE management
• ARDS - Berlin criteria, low tidal volume ventilation

3. Neurological Emergencies

• Stroke - tPA window (4.5 hrs), NIHSS, hemorrhagic vs ischemic
• Status epilepticus - Benzodiazepines → phenytoin → propofol/midazolam
• Meningitis - empiric antibiotics (don't delay for LP), dexamethasone
• Raised ICP - osmotherapy, head positioning, hyperventilation (temporizing)

4. Trauma

• ATLS primary survey - ABCDE, permissive hypotension in penetrating trauma
• Hemorrhagic shock - 4 classes, damage control resuscitation (1:1:1)
• Head injury - GCS scoring, surgical thresholds (EDH vs SDH)
• Spinal injury - NEXUS criteria, Canadian C-spine rule

5. Toxicology

• Organophosphate poisoning - SLUDGE/DUMBELS, atropine + pralidoxime
• Paracetamol overdose - Rumack-Matthew nomogram, NAC protocol
• Opioid/Benzodiazepine overdose - reversal agents, doses
• TCA overdose - sodium bicarb for wide QRS, avoid physostigmine
• Digoxin toxicity - ECG changes, Fab fragments

6. Metabolic/Endocrine

• DKA - diagnostic criteria, insulin protocol, K+ replacement pitfalls
• Hyperosmolar state (HHS) - distinguishing from DKA
• Adrenal crisis - hydrocortisone dosing
• Thyroid storm - Burch-Wartofsky score, PTU vs methimazole, SSKI timing

7. Renal/Electrolytes

• Hyperkalemia - ECG changes, calcium gluconate vs chloride, treatment ladder
• Hyponatremia - correction rate (max 8-10 mEq/24h), ODS risk
• Rhabdomyolysis - CK thresholds, aggressive IVF

8. Procedural/Airway

• RSI - drug doses (succinylcholine vs rocuronium), failed airway algorithm
• ACLS algorithms - VF/pVT, PEA/asystole, post-ROSC care
• Ultrasound in EM - FAST exam, RUSH protocol, cardiac tamponade

9. Infectious/Sepsis

• Sepsis-3 criteria - qSOFA, SOFA, fluid resuscitation bundles
• Neutropenic fever - empiric antibiotic coverage
• Necrotizing fasciitis - LRINEC score, surgical emergency

10. Obstetric Emergencies

• Eclampsia - MgSO4 dosing, labetalol/hydralazine for BP
• Ectopic pregnancy - beta-hCG discriminatory zone, methotrexate criteria
• PPH - 4 T's (tone, tissue, trauma, thrombin), uterotonics

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Exam Strategy Tips

• Pattern questions are common: ECG + clinical scenario, toxidrome identification, "what do you do next?"
• Know exact drug doses for: atropine, adenosine, epinephrine, amiodarone, labetalol, tPA
• Scoring systems are frequently tested: GCS, NIHSS, Wells, CURB-65, Killip, Rankin
• "Do first" questions - always think airway → breathing → circulation before specific treatment

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SVT with Aberrancy vs. VT - The High-Yield EM Breakdown

What is SVT with Aberrancy?

• SVT with baseline wide QRS - pre-existing fixed BBB (RBBB or LBBB present even in sinus rhythm)
• SVT with aberrancy - "functional" block in a bundle branch that occurs only during tachycardia (rate-related, because one bundle branch hasn't finished repolarizing when the next impulse arrives)

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Why Does It Matter in EM?

Golden Rule for EM exams: When in doubt, treat as VT. ~80% of WCT is VT. Giving verapamil to VT can kill the patient.

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The Big Classification - Start Here

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ECG Features That Suggest VT (not SVT with Aberrancy)

Clinical context (most important)

• Structural heart disease - prior MI, cardiomyopathy, cardiac surgery, infiltrative disease → strongly favors VT
• Age >50 with CAD history → almost always VT
• A young patient with no cardiac history, palpitations since childhood → more likely SVT with aberrancy

ECG features favoring VT

• AV dissociation = P waves marching through independently at a different rate from QRS = pathognomonic for VT
• Fusion beat = partial capture of ventricle by sinus impulse merging with VT beat = proves AV dissociation = VT
• Capture beat = sinus impulse completely captures the ventricle producing a narrow beat amid wide beats = VT

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The Brugada Algorithm (Most Tested ECG Algorithm)

1. Absence of RS complex in ALL precordial leads? → Yes = VT
2. RS interval >100 ms in ANY precordial lead? → Yes = VT
3. AV dissociation present? → Yes = VT
4. Morphology criteria for VT in both V1-V2 AND V6? → Yes = VT
5. If all 4 are NO → SVT with baseline wide QRS or SVT with aberrancy

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Morphology Criteria in Detail (Step 4 of Brugada)

If RBBB pattern (R' in V1):

If LBBB pattern (S in V1):

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Other Causes of Wide-Complex Tachycardia (don't forget)

• Antidromic AVRT (WPW) - delta waves, accessory pathway conducts antegrade
• Pre-excited AF - irregular, very fast, life-threatening - avoid AV nodal blockers
• Hyperkalemia - sine wave pattern, no discrete P waves
• Flecainide/class IC toxicity - drug-induced conduction slowing
• Fascicular tachycardia - relatively narrow WCT, RBBB + left axis, responds to verapamil (exception to the rule)

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EM Management Algorithm

Wide Complex Tachycardia
         |
    Haemodynamically unstable? (hypotension, shock, pulmonary oedema, chest pain)
         |
       YES → Synchronized DC cardioversion immediately
         |
        NO
         |
    Apply Brugada criteria + clinical context
         |
    VT likely (>80% chance) → IV Amiodarone 150 mg over 10 min, then 1 mg/min
         |
    SVT with aberrancy confirmed? → Adenosine 6 mg IV rapid push
         |
    Still uncertain? → Treat as VT (never give CCBs or beta-blockers)

Exam trap: Adenosine can be used diagnostically even in WCT - if it terminates the rhythm or transiently shows underlying SVT pattern, it confirms SVT with aberrancy. It will not harm VT (just transiently blocks AV node, may cause brief AV dissociation visible on monitor).

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High-Yield Exam Summary

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Pulmonary Embolism - Complete EM Exam Guide + Latest 2026 Guidelines

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🔴 BREAKING: 2026 AHA/ACC Guideline (Brand New!)

• Introduces the AHA/ACC Acute PE Clinical Categories (replaces older massive/submassive/low-risk terminology)
• Strong recommendation for Pulmonary Embolism Response Teams (PERTs) as a new care standard
• Encourages more outpatient management of low-risk PE
• Addresses catheter-directed therapies more explicitly for intermediate/high-risk PE

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Classification - Start Here

Classic Classification (ESC-based, still widely used in exams)

2026 AHA/ACC New PE Clinical Categories

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Clinical Features

• Dyspnoea + Chest pain (pleuritic) + Haemoptysis

• Tachycardia (most sensitive sign)
• Unexplained dyspnoea at rest or exertion
• Pleuritic chest pain
• Syncope (suggests massive PE with RV failure)
• Signs of DVT (unilateral leg swelling)

• Sinus tachycardia (most common)
• S1Q3T3 pattern (S wave in lead I, Q wave + T-wave inversion in lead III)
• T-wave inversion V1-V4 (right heart strain)
• Incomplete/complete RBBB
• Right axis deviation
• Note: normal ECG does NOT exclude PE; these findings increase probability

• Cardiomegaly, basilar atelectasis, pleural effusion
• Westermark's sign - focal oligaemia (hyperlucency from obstructed lobar artery) - <5%
• Hampton's hump - peripheral wedge-shaped opacification (pulmonary infarction) - <5%
• Normal CXR with hypoxaemia = high suspicion for PE

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Risk Stratification Scores

Wells Score for PE (Original)

• 6 = High risk (78% probability of PE)

• 2-6 = Moderate risk (28%)
• <2 = Low risk (3.4%)
• Dichotomous version: >4 = PE likely (go straight to CTPA); ≤4 = PE unlikely (D-dimer first)

PERC Rule (PE Rule-Out Criteria)

If PERC = 0 (all absent) → PE excluded. No D-dimer needed. If any 1 PERC criterion present → go to D-dimer/Wells pathway

sPESI (Simplified PESI) - for low-risk identification

• sPESI = 0 → low risk, consider early discharge/outpatient treatment

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Diagnostic Algorithm

• Low probability (Wells 0-1): Check PERC → if 0, PE ruled out; if ≥1, D-dimer
• Moderate probability (Wells 2-6): D-dimer → if negative, PE ruled out; if positive, CTPA
• High probability (Wells ≥7): Go straight to CTPA

Age-Adjusted D-dimer (High Yield!)

• Cutoff = Age × 10 µg/L (FEU units)
• E.g., 70-year-old: D-dimer cutoff = 700 µg/L instead of 500 µg/L
• Reduces unnecessary CTPA in elderly without sacrificing sensitivity

YEARS Algorithm (newer, increasingly used)

• If 0 criteria: D-dimer threshold = 1000 µg/L
• If ≥1 criterion: D-dimer threshold = 500 µg/L (standard)
• If threshold exceeded → CTPA

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Imaging

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Treatment

1. Hemodynamically Unstable (Massive/High-Risk PE)

Massive PE (shock/arrest)
    ↓
Immediate anticoagulation (heparin UFH bolus 80 U/kg IV)
    ↓
Systemic thrombolysis - FIRST LINE
  • Alteplase (tPA) 100 mg IV over 2 hours
  • For cardiac arrest: 50 mg rapid bolus
    ↓
If thrombolysis fails/contraindicated:
  • Catheter-directed therapy (CDT) or mechanical thrombectomy
  • Surgical embolectomy (last resort)

• Prior intracranial haemorrhage
• Recent (<3 months) ischaemic stroke
• CNS tumour/AVM
• Recent (<3 months) head trauma/surgery
• Active internal bleeding (not menses)

2. Hemodynamically Stable + RV Dysfunction (Submassive/Intermediate-High Risk)

• Anticoagulation with LMWH or UFH
• Do NOT give routine systemic thrombolysis (risk of major haemorrhage, especially ICH, outweighs benefit in stable patients)
• Rescue thrombolysis if clinical deterioration occurs
• CDT (catheter-directed thrombolysis at low dose, e.g., tPA 2 mg/hr via catheter) - may be considered in selected patients (high bleeding risk for systemic lysis)
• PERT team consultation (per 2026 AHA/ACC guideline)

3. Low-Risk PE

• Anticoagulation - DOACs preferred
• Early discharge/outpatient treatment if sPESI = 0 and no other barriers (supported by 2026 AHA/ACC, ESC, CHEST)
• Hestia criteria can also be used to identify suitability for home treatment

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Anticoagulation - Drug Choice

• Provoked PE (reversible trigger - surgery, immobilisation): 3 months
• Unprovoked PE or persistent risk factors: ≥3-6 months, consider extended therapy
• Recurrent VTE or antiphospholipid syndrome: Indefinite

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IVC Filter

• Acute PE + absolute contraindication to anticoagulation
• Does NOT reduce PE recurrence or mortality - all guidelines agree

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Biomarkers in PE

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Echo Findings in Massive PE

• RV dilatation (RV:LV ratio ≥1.0 on echo or CTPA)
• RV hypokinesis with sparing of the apex (McConnell's sign - RV free wall hypokinesis, apex normal)
• Tricuspid regurgitation, elevated RVSP
• TAPSE <16 mm (RV systolic dysfunction)
• Paradoxical interventricular septal shift ("D-sign")
• Thrombus in right heart

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High-Yield Exam Summary Table

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