Respiratory failure is nearly any condition that affects
breathing function or the lungs themselves and can result in
failure of the lungs to function properly. The main tasks of the
lungs and chest are to get oxygen from the air that is inhaled
into the bloodstream, and, at the same to time, to eliminate
carbon dioxide (C02) from the blood through air that is breathed
out. In respiratory failure, the level of oxygen in the blood
becomes dangerously low, and/or the level of C02 becomes
dangerously high. There are two ways in which this can happen.
Either the process by which oxygen and C02 are exchanged between
the blood and the air spaces of the lungs (a process called "gas
exchange") breaks down, or the movement of air in and out of the
lungs (ventilation) does not take place properly. Respiratory
failure often is divided into two main types. One of them,
called hypoxemic respiratory failure, occurs when something
interferes with normal gas exchange. Too little oxygen gets into
the blood (hypoxemia), and al