Rescue breaths push air from your lungs into someone else’s to keep oxygen flowing when they can’t breathe on their own. The air you exhale contains about 16% to 17% oxygen, which is enough to sustain life during an emergency. The technique is straightforward, but small details in positioning and timing make the difference between air reaching the lungs and going nowhere.
The Basic Technique for Adults
Every rescue breath starts with opening the airway. Place your palm on the person’s forehead and gently tilt their head back. With your other hand, lift the chin forward. This head-tilt, chin-lift maneuver pulls the tongue away from the back of the throat and creates a clear path for air.
Once the airway is open, pinch the person’s nose closed with the hand that’s on their forehead. Place your mouth completely over theirs so no air escapes around the edges. Breathe into their mouth for one second, watching their chest as you do. If the chest rises, the air went into the lungs. Remove your mouth to let the air flow back out, then deliver the second breath the same way.
The visual check matters more than how hard you blow. You’re aiming for just enough air to make the chest visibly rise. Blowing too hard or too fast forces air past the airway and into the stomach, which can cause vomiting and make resuscitation harder. A normal breath, not a deep gulp of air, is all you need.
How Rescue Breaths Fit Into CPR
During CPR on an adult or child, rescue breaths alternate with chest compressions at a ratio of 30 compressions to 2 breaths. You push hard and fast 30 times, pause briefly to deliver two breaths, then immediately return to compressions. The pause for breaths should be as short as possible.
If the person has a pulse but isn’t breathing (a situation called respiratory arrest rather than cardiac arrest), you skip compressions entirely and give one breath every six seconds, which works out to about 10 breaths per minute. Keep checking for a pulse every two minutes while providing these breaths.
Differences for Children and Infants
For children roughly age one through puberty, the technique is nearly identical to the adult version. Tilt the head back, pinch the nostrils shut, seal your mouth over theirs, and breathe for one second while watching the chest. Because a child’s lungs are smaller, less air is needed to produce a visible chest rise.
Infants under one year require a different seal. Instead of covering just the mouth, you cover both the baby’s mouth and nose with your mouth at the same time. Take a normal breath (not a deep one) and give a gentle puff lasting one second. Watch for the chest to rise. The volume of air that makes an infant’s chest rise is very small, so blow softly. Overinflating an infant’s lungs can cause serious harm.
When the Chest Doesn’t Rise
The most common reason a rescue breath fails is an airway that isn’t properly opened. If the chest doesn’t rise on your first breath, reposition the head by re-doing the head-tilt, chin-lift before giving the second breath. A slightly deeper tilt or a firmer chin lift often solves the problem immediately.
If repositioning doesn’t help, something may be physically blocking the airway. Each time you open the airway during CPR, glance into the mouth. If you can see a solid object, remove it. Don’t blindly sweep a finger around inside the mouth, as this can push an unseen object deeper. If a conscious person was choking before becoming unresponsive, alternate between abdominal thrusts (delivered in rapid sequence) and checking the airway until the obstruction clears.
Using a Pocket Mask
Mouth-to-mouth contact carries a small risk of exposure to blood, vomit, or infectious fluids. A pocket mask is a small, portable barrier device that sits over the person’s face with a one-way valve for you to breathe through. Air flows into the person’s lungs, but nothing flows back toward you.
To use one, place the mask over the person’s mouth and nose, tilt the head back with a chin lift just as you would for regular rescue breaths, and blow into the valve. Watch for the chest to rise, then remove your mouth from the valve so the person can passively exhale. Leave the mask in place between breaths and readjust it if you notice air leaking around the edges. The technique is the same as direct mouth-to-mouth in every other respect: one second per breath, just enough air for a visible chest rise.
Avoiding Stomach Inflation
When air enters the stomach instead of the lungs, it causes the abdomen to distend. This raises pressure inside the chest, reduces blood flow back to the heart, and increases the chance the person will vomit. Vomit in the airway during resuscitation is dangerous and difficult to manage.
Stomach inflation happens when airway pressure gets too high. The most common causes are blowing too hard, blowing too fast, delivering too much air per breath, or failing to fully open the airway. The fix is simple in principle: tilt the head back properly, blow gently, and take a full second to deliver each breath. Even with perfect technique, some air will enter the stomach. Keeping your breaths slow and measured minimizes how much.