# First Aid/B for Breathing
## Principles

Humans breathe by inhaling fresh air into the lungs, exchanging part (but not all) of the oxygen in it with unneeded carbon dioxide, and exhaling the spent air. Blood vessels located in the lungs distribute oxygen throughout the cells of the body. Human beings typically have a lung capacity of 4 to 6 liters.
When someone stops breathing, this is a life threatening condition known as respiratory arrest. Occasionally when a victim stops breathing, their breathing can restart if stimulated by a rescuer blowing air into their lungs. However, a victim in respiratory arrest is likely to fall into cardio-respiratory arrest, which means that they are no longer breathing and their heart has also stopped.
Without their lungs receiving oxygen, a victim will suffer permanent brain damage after only a few minutes. Because of this, it is crucial that rescuers provide rescue breathing (ventilation) quickly and correctly.

## Checking the respiration

After opening the victim's airway, check to see if the victim is breathing. To do this, place your cheek in front of the victim's mouth (about 3–5 cm away) while looking down their chest (towards their feet). If desired, you can also gently place a hand on the center of the victim's chest. This allows you to observe whether the victim is breathing in the following ways:
* You may Feel the victim's breath against your cheek.
* You may Hear the air entering or escaping your victim's lungs.
* You may See the chest rise and fall with each breath.
* You may Smell the breath of the victim as they exhale.
If you have placed your hand on the victim's chest, you may also feel their chest rise and fall against your hand. Search for these signs for 10 seconds. If there is no breathing (or it is slower than 6 times per minute), your victim is not adequately moving air in and out of their body. In order to help them, you must perform rescue breathing.

## Calling For Help

If a bystander has not already summoned assistance, now is the time to make sure that emergency personnel are enroute (known as EMS, Ambulance Service, Rescue Squad, or Paramedics depending on the region). Ideally, someone else will be able to make the call while you continue aid. If you're alone, you must stop and call yourself.
* Europe: 112
* USA & Canada: 911
* Australia: 000
* United Kingdom: 999 or 112
You will need to give the emergency services:
* Your exact location (including apartment number, suite, building, etc.)
* The illness or injury that the victim is having (to the best of your knowledge).
* A telephone number you can be contacted back on (for instance, if they have difficulty finding you)
In some cases, the person taking your call will run through a list of questions with you in order to make sure the proper resources are sent to you. Also, some localities will give the caller instructions on what to do before help arrives.
Sometimes, the victim must be left unattended while the first aider leaves to seek help for them. If the victim is unconscious they should be left in the recovery position so they do not choke if they vomit. However, if you suspect the victim has an injury to their neck or back, they should not be moved and their head kept stationary, with two exceptions. One, if the victim is in immediate danger (such as from a fire), they should be moved regardless. Two, if the victim is unconscious, the threat of choking outweighs the potential injury to their neck or back, and they should be placed on their side anyway. There are alternative methods for safer positioning available to those with more advanced training.(See Suspected Spinal Injury for more information.)

## Rescue Breaths

Rescue breaths must be provided to victims in a state of respiratory arrest; do not provide them to a weakly breathing victim. If you cannot detect the breath of the victim, or they are breathing slower than once every ten seconds, begin rescue breathing.
If you have a CPR mask or other barrier device, you can use it to protect yourself and the victim from exchange of body fluids. Cheap, keyring-sized CPR masks are available in most pharmacies. Be sure to read the instructions and practice with any equipment you buy. In the event you do not have a barrier device, the rescuer should perform as best they can, given the situation and abilities. If you are uncomfortable performing direct mouth-to-mouth on a stranger, or you find blood or other bodily fluids present, you are not obligated to. You should, however, perform the chest compression portion of CPR, as it is better than doing nothing.
The 2010 CPR guidelines changed CPR so compressions are started first, after checking for breathing.
To give two rescue breaths:
* Kneel at the level of the victim, perpendicular to and facing them.
* Maintain an open airway using the head-tilt chin-lift.
* Squeeze the nose of the victim with your free hand to seal it shut.
* Put your mouth on the mouth of the victim in an airtight manner, and blow into the mouth of the victim so that their chest beings to rise. Never blow forcefully, as this may cause the air to enter the stomach and not their lungs. Instead, exhale smoothly over 1–2 seconds.
* Remove your mouth, and let the victim exhale completely (watch for their chest to fall).
* Repeat the above steps for your second breath.
If your breaths do not go in easily, or the victim's chest did not rise, the airway could have again become closed. Open the airway once again with the head-tilt chin-lift technique and try again, making sure the victim's neck is extended and their head is rocked back fully.
Continue with CPR compressions.