Mouth-to-mouth resuscitation is a form of rescue breathing in which a rescuer breathes air directly into the mouth of a person who has stopped breathing, aiming to fill their lungs and maintain oxygenation until normal breathing resumes or medical help arrives. It is one component of cardiopulmonary resuscitation (CPR) alongside chest compressions.
The technique involves pinching the patient’s nostrils closed to prevent air escaping through the nose; tilting the head back and lifting the chin to open the airway and move the tongue away from the back of the throat; creating a firm seal around the patient’s mouth; and breathing in slowly and steadily until the chest visibly rises. In adults, rescue breaths are approximately 500 to 600 ml per breath. In current guidance, 30 chest compressions are alternated with 2 rescue breaths (30:2 ratio).
Current resuscitation guidelines acknowledge that mouth-to-mouth resuscitation can be a barrier for some bystanders due to concerns about infection or reluctance to perform the technique on a stranger. For this reason, compression-only CPR (continuous chest compressions without rescue breaths) is recommended for untrained bystanders as an acceptable alternative, as compressions alone substantially improve survival compared to doing nothing. Trained rescuers who are confident in their technique should continue to provide both compressions and ventilations.
Face shields and pocket masks provide a barrier between the rescuer’s mouth and the patient’s, addressing infection concerns while still delivering the benefit of rescue breaths.
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