Version control: This document is current with respect to 2015 American Heart Association® Guidelines for CPR and ECC. These guidelines are current until they are replaced on October 2020. If you are reading this page after October 2020, please contact ACLS Training Center at for an updated document.

For laypersons or other non-HCP personnel

The simplified ADULT BASIC LIFE SUPPORT algorithm includes five steps. The algorithm diagram provided by the American Heart Association® emphasizes the following:

1. Assess the victim's responsiveness. If a victim is not breathing, or is not breathing normally (i.e., gasping), initiate CPR. Health care professionals should be trained to recognize cardiac arrest that presents as seizure-like activity or with agonal respirations.

2. Activate EMS (Emergency Medical Response) by calling 911.

3. Retrieve a defibrillator, usually an automatic external defibrillator (AED).

4. The algorithm proceeds in a loop of CPR and rhythm checks with defibrillation.

5. Check PULSE before chest compressions for at least five seconds and no more than ten seconds. If in doubt, begin compressions.

6. CPR: push hard and fast. Begin chest compressions before ventilation. Chest compressions allow blood flow to the heart and brain. Delays in chest compressions result in diminished survival. Be sure to allow the chest to recoil between compressions. The chest should be compressed 100-120/min to a depth of 2-2.4” (5-6cm)

7. For effective breathing, watch for chest rise and avoid excessive ventilation. 10 BREATHS should be delivered each minute, or one breath every six seconds. Each breath should be delivered over 1 second. Observe visible chest rise.

Avoid gastric inflation, as it may result in aspiration, pneumonia or vomiting.

8. The ratio of chest compressions to breaths is 30 to 2.

10. After the defibrillator becomes available, check rhythm. USE THE AED WHEN INDICATED AND AVAILABLE. The victim should receive a shock that is repeated every two minutes or 5 cycles.

BLS algorithm feedback and questions

I'm a certified ACLS provider by AHA, currently working as a ship's doctor on a german ship. My German colleagues assert that it is no longer necessary to check pulse before starting the chest compressions, and it is recommended only to check responsiveness and breathing. Could you let me know about it please?

The AHA Guidelines uses the “absence of normal breathing” as indication for chest compressions when teaching lay rescuers. In the health professional certification, healthcare providers are taught to first check for presence or absence of normal breathing, then to check a pulse. No more than ten seconds should be taken to do this and if there is any doubt of the existence of a pulse, compressions should be started. There is no harm in doing compressions if a pulse is present, but delaying them when a pulse is not present ensures poor outcome. I hope this answers helps to clarify the guidelines for you.