Monitor and maintain an open airway at all times. The provider must decide if the benefit of adding an advanced airway outweighs the risk of pausing CPR. If the victim’s chest is rising without using an advanced airway, continue giving CPR without pausing. However, if you are in a hospital or near trained professionals who can efficiently insert and use the airway, consider pausing CPR.


In cardiac arrest, administer 100% oxygen. Keep blood O2 saturation (sats) ≥ 94% as measured by a pulse oximeter. Use quantitative waveform capnography when possible. Normal partial pressure of CO2 is between 35 and 40 mmHg. High quality CPR should produce a CO2 between 10 to 20 mmHg.


Obtain intravenous (IV) access when possible; intraosseous access (IO) is also acceptable. Monitor blood pressure with a blood pressure cuff or intra-arterial line if available. Monitor the heart rhythm using pads and a cardiac monitor. When using an AED, follow the directions (i.e., shock a shockable rhythm). Give fluids when appropriate. Use cardiovascular medications when indicated.


Start with the most likely cause of the arrest and then assess for less likely causes. Treat reversible causes and remember to continue CPR as you create a differential diagnosis. Stop only briefly to confirm a diagnosis or to treat reversible causes. Minimizing interruptions in perfusion is key.

  • Maintain airway in unconscious patient
  • Consider advanced airway
  • Monitor advanced airway if placed with quantitative waveform capnography
  • Give 100% oxygen
  • Assess effective ventilation with quantitative waveform capnography
  • Do NOT over-ventilate
  • Evaluate rhythm and pulse
  • Defibrillation/cardioversion
  • Obtain IV/IO access
  • Give rhythm-specific medications
  • Give IV/IO fluids if needed
  • Identify and treat reversible causes
  • Cardiac rhythm and patient history are the keys to differential diagnosis
  • Assess when to shock versus medicate