Cardiopulmonary Resuscitation (CPR)

Cardiopulmonary resuscitation (CPR) is an emergency procedure used in patients with cardiac arrest. Cardiopulmonary resuscitation combines the use of chest compressions, artificial ventilation, and, when available, an automatic external defibrillator (AED) to maintain circulatory flow and oxygenation to vital structures. Cardiopulmonary resuscitation is an integral part of basic life support (BLS) and advanced cardiovascular life support (ACLS). High-quality CPR improves the likelihood of survival. Some patients in critical situations request a do not resuscitate (DNR) order, which instructs health care providers not to do CPR if a patient suffers cardiac arrest.

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  • Annual incidence of sudden cardiac arrest in the United States: 180,000–450,000 +
  • Cardiopulmonary resuscitation (CPR) is attempted in approximately ⅔ of cases.
  • Early initiation of high-quality CPR has been shown to dramatically increase survival rate.

Cardiopulmonary resuscitation sequence overview

Cardiopulmonary resuscitation consists of chest compressions and rescue breaths carried out sequentially. 

  • Identification of cardiac arrest:
    • Patient seen losing consciousness or found unconscious 
    • Assess scene for safety.
    • Feel pulse and assess breathing simultaneously:
      • Carotid pulse should be felt for no longer than 10 seconds.
      • Look for chest movement, and listen and feel for air movement (patient may be apneic or with abnormal or agonal breathing).
  • Prepare for CPR:
    • Activation of emergency response system:
      • Outside hospital, call 911.
      • In hospital, call cardiac arrest code.
    • Obtain automatic external defibrillator (AED), if available.
  • If pulse is present, but no breathing:
    • Provide rescue breath (1 every 6 seconds).
    • Recheck pulse every 2 minutes.
  • If no pulse present:
    • Start with chest compressions before giving rescue breath.
    • If trained in CPR, initiate CPR at rate of 30 chest compressions followed by 2 rescue breaths (30:2).
    • If sole lay rescuer, compression-only CPR (CPR without mouth-to-mouth breaths)
    • Apply AED as soon as available.
    • Continue CPR and deliver shocks as directed by AED.

Related videos

Rescue Breaths

Rescue breath technique

  • If possible, use face shield or other form of personal protective equipment (PPE).
  • Clear mouth of objects before rescue breaths. 
  • Tilt head back slightly.
  • Lift chin. 
  • Pinch nose.
  • Place your mouth fully over theirs. 
  • Blow hard enough to get chest rise (retilt head if chest does not rise).
Rescue breath technique

Rescue breath technique
Rescue breaths should be provided to apneic patients during CPR. Chest compressions should take precedence, especially in children, over rescue breaths.

Image by Lecturio.

Heimlich maneuver

If patient’s chest does not rise, foreign object may be obstructing airway:

  • With patient supine → open airway using jaw lift →  if foreign body is visible, remove object with finger sweep (do not perform blind finger sweep).
  • Attempt rescue breaths → if unsuccessful, retilt head and reattempt rescue breaths.
  • If no chest rise → kneel next to or straddle hips of patient → use 2 hands on top of each other and place heel of bottom hand below xiphoid process → press both hands into abdomen with quick upward thrust 5 times.
  • Open airway with jaw lift → if foreign body is visible, remove it → if not, repeat Heimlich maneuver until ventilation is successful.
Heimlich maneuver

Heimlich maneuver
In a choking patient or an unconscious patient on whom rescue breaths are not providing adequate ventilation, airway obstruction with a foreign object should be considered. The Heimlich maneuver works by producing positive pressure in the lungs, forcefully expelling any foreign body in the upper airway.

Image by Lecturio.

Chest Compressions


  • Patient must be supine.
  • Patient must be lying on a firm surface.


  • In adults, use 2-hand chest compression technique:
    • 1 hand on top of the other 
    • Place heel of bottom hand over lower portion of the sternum, slightly below nipples.
  • Push “hard and fast”: 
    • Appropriate rate: 100–120 compressions/min
    • Adequate depth: 5.0–7.6 cm (2–3 in) 
    • Allow full chest recoil.
Chest compressions

Hand placement in CPR for adults, children and infants
Hand positioning and depth of chest compression vary among adults, children and infants, while rate remains consistent.

Image by Lecturio.

Limit pauses during CPR

  • Pause only to give rescue breaths.
  • If possible, have other providers prepare to take turns performing compressions (change every 2 minutes).
  • Avoid hyperventilation: ventilation rate around 6/min


Early defibrillation has been shown to significantly improve morbidity and mortality in ventricular fibrillation (VF)/ventricular tachycardia (VT) cardiac arrest.


  • Chest compressions should be initiated before placing defibrillator.
  • Rhythm analysis/shock should be performed as soon as possible without interrupting high-quality chest compression.
  • Ideal timing is to pause between switching providers; done every 2 minutes.


  • Different models vary slightly, so follow instructions provided.
  • Usually, 1 pad is placed under the right collarbone and the other on the left side of the chest.

Analysis and shock

  • Providers should not touch the patient during analysis/shock.
  • AED automatically analyzes patient rhythm and suggests shock delivery and voltage.
  • Repeat analysis every 2-minute cycle.

Differences in Children

Rescue breaths

  • Order of CPR:
    • Cardiac arrest in children is often due to hypoxia.
    • Perform 2 rescue breaths before starting compressions.
  • Differences in technique:
    • If choking suspected, do not use Heimlich maneuver:
      • Use back blows in infants.
      • Use chest thrusts in small children.
    • Positioning of mouth:
      • For infants, place your mouth over their nose and mouth. 
      • For children, pinch their nose shut and place your mouth over theirs.
Back blows and chest thrusts

Back blows and chest thrusts (CPR in children)

Image by Lecturio.

Chest compressions

  • In infants, use 2-finger technique or 2-thumb technique (when hands can fit around child).
  • In children, use 1-hand technique in center of chest.


  • Pediatric pads should be utilized:
    • Different size and shape
    • Different positioning
  • Voltage should be lowered, as specified by instructions in defibrillator.

Do Not Resuscitate (DNR)

A DNR order is a medical order, part of a patient’s advance directives.

Do not resuscitate orders prevent healthcare providers from performing the following procedures in case a patient’s breathing stops or heart rate stops:

  • CPR (chest compressions, artificial breathing)
  • Electrical cardioversion
  • Administering antiarrhythmic medications or cardiac resuscitation medications (e.g., epinephrine)

Advance directives:

  • Patient’s ability to decide and reflect on their wishes about future medical care
  • Can be provided by family members (surrogate decision-maker)
  • Often includes more than a DNR order (e.g., vegetative state directives)

Being under a DNR order does not prohibit patients from receiving appropriate medical care (surgeries, biopsies, dialysis, blood samples, move to intensive care unit (ICU), etc.).


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  2. Ralston, M. (2020). Pediatric basic life support (BLS) for health care providers. UpToDate. Retrieved December 10, 2020, from
  3. Silveira, M. (2020). Advance care planning and advance directives. UpToDate. Retrieved on December 10, 2020, from
  4. Brown III, C. (2020). The decision to intubate. UpToDate. Retrieved December 10, 2020, from
  5. Tintinalli JE, et al. (2016). Resuscitation of children. In: Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, N.Y.: The McGraw Hill Companies.
  6. Kleinman ME, et al. (2015). Part 5: Adult basic life support and cardiopulmonary resuscitation quality — 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation.
  7. Kong MH et al. (2011). Systematic review of the incidence of sudden cardiac death in the United States. J Am Coll Cardiol.
  8. McNally B et al. (2005–2010). Centers for Disease Control and Prevention. Out-of-hospital cardiac arrest surveillance — Cardiac Arrest Registry to Enhance Survival (CARES), United States.
  9. Berg RA et al. (2010). Part 5: Adult basic life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation.

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