Basic Life Support Algorithms

Adult Cardiac Arrest Algorithm: Step by Step

1. 1

   Confirm that the scene is safe

2. 2

   Check responsiveness and call for help

   • Check responsiveness
   • Call for help
   • Activate the emergency response system (ERS)
   • Send someone for an AED/defibrillator
3. 3

   Check pulse and breathing simultaneously

   Perform this check for no more than 10 seconds. Abnormal breathing means absent or ineffective breathing, including gasping.

   • Pulse felt, breathing normal: monitor the patient until advanced responders arrive
   • Pulse felt, breathing abnormal: begin rescue breathing
   • Pulse not felt, breathing abnormal: start CPR
4. 4

   Pulse felt, breathing abnormal: rescue breathing

   • Give 1 breath every 6 seconds (10 breaths/min)
   • Reassess the pulse every 2 minutes and start CPR if no pulse is detected
   • For suspected opioid overdose, give an opioid antagonist, such as naloxone
5. 5

   Pulse not felt, breathing abnormal: start CPR

   • Begin high-quality CPR cycles immediately (30 chest compressions : 2 rescue breaths)
   • Apply the AED/defibrillator as soon as it is available
   • For suspected opioid overdose, consider giving an opioid antagonist, such as naloxone
6. 6

   Check the rhythm when the AED/defibrillator is available

   Is the rhythm shockable?

   • Shockable: deliver 1 shock, then immediately resume high-quality CPR for 2 minutes (or until the AED/defibrillator prompts the next rhythm check)
   • Nonshockable: immediately resume high-quality CPR for 2 minutes (or until the AED/defibrillator prompts the next rhythm check)
   • Keep providing CPR until ALS providers take over or the patient shows movement