In cardiac arrest the heart stops pumping blood effectively, so the patient is unresponsive with no normal breathing and no pulse. Survival depends on fast CPR and early defibrillation, followed by treatment of the cause and good care after the heart restarts.
Key symptoms
- Sudden collapse and unresponsiveness
- No breathing or only gasping
- Sometimes chest pain, palpitations or breathlessness just before
What you find on exam
- Check responsiveness, breathing and a central pulse in no more than 10 seconds
- Rhythm on the monitor or AED: VF, pulseless VT, PEA or asystole
- End-tidal carbon dioxide to judge CPR quality and return of circulation
- Clues to a cause: trauma, overdose, hypothermia, drowning
Tests
- Rhythm check every 2 minutes
- Blood glucose, potassium and blood gas
- Point-of-care ultrasound for tamponade, pneumothorax or no heart motion
- 12-lead ECG after return of circulation
Treatment basics
- High-quality CPR: rate 100 to 120, depth at least 5 cm, full recoil, few pauses
- Shock VF or pulseless VT as soon as possible
- Epinephrine 1 mg IV or IO every 3 to 5 minutes
- Amiodarone or lidocaine for shock-resistant VF or VT
- Treat reversible causes (Hs and Ts) and give post-arrest care
Red flags
- Unresponsive with gasping or no breathing
- End-tidal carbon dioxide under 10 mmHg during CPR
- Long pauses in compressions
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Related guides
Sources: AHA Guidelines for CPR and ECC; NASEMSO National Model EMS Clinical Guidelines; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.