CPR First Aid Rescue Breathing

In First Aid, the new style CPR calls for two rescue breaths to be given followed by 30 compressions. To effectively apply these two rescue breaths it is necessary to be proficient in the application of the appropriate head tilt and the pistol grip as detailed in the two previous posts on CPR.

The CPR operator needs to be aware of how much air to breathe in. You only need to give a chest rise; in other words, share your breath with them.

The average adult has about one to one and a half litres of air in their lungs. Each breath taken replaces about 500mls. The air we breath contains about twenty to twenty-one percent oxygen. We use about four or five percent and breathe out about sixteen percent of the oxygen. Therefore when giving CPR to another adult the two of you would use about nine or ten percent of the oxygen contained in the air you breathed in and between the two of you about half the oxygen content would be breathed out again along with carbon dioxide etc.

If you want to get a greater concentration of oxygen into a casualty you need to be trained and have access to medical oxygen.

Obviously when we breathe, we do not totally expel all the air from our lungs, nor do we breathe in so much that our lungs are totally expanded. Its not natural is it? Therefore it is common sense that when we breathe into another person whilst doing CPR, it is neither necessary nor correct to over inflate their chest.

I cringe when I pick up first aid instruction books encouraging people to give "two full breaths". Naturally this implies that you take an enormous breath and blow hard. Bad Bad Bad. We are not trying to blow the socks clean off them. Think about it. Also you yourself will soon get out of breath.

Where will the excess air go after the chest has been filled?
Answer - Into the stomach
Result - they will quite likely throw it all back up.

Further, I would put it to you that when you try to perform compressions, the excess air in the chest will lessen the effectiveness of the first couple of pumps.

When giving CPR to a child the breath would be much less, so once again look for the chest rise.

In an infant under twelve months of age use a cheek puff - fill one cheek and blow it out gently as if you were trying to gently blow a feather off the end of your fingers. You need to place your mouth over both the nose and mouth of the infant.

After you give the first breath, lift your head (similar to how you would lift your head when freestyle swimming) and look at the chest. You can then take a fresh breath away from their mouth so you do not breath in what they are expelling.

After you give the second rescue breath - get up and get ready to start compressions.

Time is of the essence.

Next post - about giving compressions