advanced practice nurse a registered nurse having education beyond the basic nursing education and certified by a nationally recognized professional organization in a nursing specialty, or meeting other criteria established by a Board of Nursing.
Quick Answer. The air that makes up Earth's atmosphere contains 20.9 percent oxygen. This is true up to about 70,000 feet above sea level. However, above 10,000 feet, the atmosphere becomes too thin to support human life, even though its proportions do not change much. Continue Reading.
Due to some heart and lung conditions, not enough oxygen is able to get into your blood to supply your body. Once your condition has been stabilized by medications, supplemental oxygen is used to correct a low oxygen level. This is a common misconception that many people using oxygen have heard. The air we breathe is 21% oxygen. Most people using oxygen are only receiving a slightly higher percentage (about 28% at 2 lpm). This is just enough to bring your blood oxygen levels back to an adequate level.