If What We Exhale Is Mostly Carbon Dioxide, How Is Giving Cpr To A Dying Person Helpful?
Your question’s premise is completely wrong.
Inhaled air = 21% oxygen, 89% nitrogen
Exhaled air = 17% oxygen, 4% carbon dioxide, 89% nitrogen
17% inspired oxygen is better than 0%. Actually, it’s compressions that are the most important in CPR.
Related posts:
- Why Is It Ok To Give Cpr Using Air That Contains Carbon Dioxide Into An Unresponsive Person?
- When You Are Doing Cpr, Why Do You Breathe Into The Mouth Of The Victim, Don’t You Breathe Out Carbon Dioxide?
- Why Do We Give Rescue Breaths During Cpr When We Are Breathing Out Carbon Dioxide And The Patient Needs Oxygen?
- How Does Cpr Work If You Breathe In Air And Breathe Out Carbon Dioxide?
- How Does Cpr Work? Are My Statements Flawed?
February 4, 2010 @ 9:55 am
We actually exhale about 15%-17% oxygen (compared to 21% in air), which is barely enough to keep a person alive. Of course, if a professional does it, they use a bag and mask, often connected to an oxygen tank. This increases the amount of oxygen to improve the effectiveness of the CPR.
February 4, 2010 @ 11:53 am
Let look at giving breath in a completely different way: (and the info about just less pecentages of 02 is accurate). Your breaths are “testing” the system to see if they actually need CPR. This is especially true in a lay rescuer (home) …. NOT health care (clinical) environment. If the patient is so “dying” that they accept your breath and don’t cough it back your face.. move on to Deep Chest Compressions with Open Airway which allow for a significant amount of air to be forced out of the chest and during FULL recoil….. air reenters the chest… Thus.. “Compression-Only” CPR (or Much higher ratios of Compressions to Ventilations). BTW, Why is “compression- only” CPR not recommended for Infants and Children??? because the majority of the time when you give a couple of breaths to the “dying” pediatric…. they cough it back. and you realise they don’t need Full CPR and you BACK off… and protect the child until EMS arrives. Thanks
February 4, 2010 @ 6:44 pm
When you run into that kind of question, the first thing to do is check your premise. Exhaled air, just like inhaled air, is mostly nitrogen, with substantial (though slightly reduced, in comparison) levels of oxygen and increased but still small levels of carbon dioxide.
February 4, 2010 @ 8:33 pm
In a given breath, a human only extracts about 10% of the oxygen they inhale.
In CPR, the goal is to get any oxygen at all in the lungs. This will oxygenate the blood in the lungs, and pumping their chest helps blood circulation, getting the oxygen to their brain.
February 5, 2010 @ 1:00 am
When we inhale 21% of that air is oxygen and when we exhale we only use 4% of oxygen of that air, so there’s still 17% oxygen in the air that goes into his/her lungs and he/she can use it.
February 5, 2010 @ 1:37 am
you are wrong. what we exhale is not mostly CO2, it contains enough O2.
February 5, 2010 @ 4:39 am
It’s not really about putting oxygen into their lungs, it’s more about getting AIR in general into their lungs so that their lungs will start to expand and contract again in the typical breathing fashion.