Respiratory failure occurs when the respiratory system is no longer able to provide enough oxygen requirements or remove enough carbon dioxide from the body. Hypoxia (not enough oxygen is reaching the tissues) may occur unless there are interventions. Large amounts of carbon dioxide may also build up in respiratory failure.

Mechanical Ventilation
This is the use of a ventilator (sometimes called a life support machine) to do the breathing for a patient experiencing respiratory failure. The ventilator fills the lungs with air, thereby providing oxygen to, and removing carbon dioxide from, the body via the lungs.

Usually the ventilator delivers oxygen directly into the airway of the patient. This is done using an endotracheal tube which is a plastic tube that is passed through the mouth into the larynx (the top of the trachea or windpipe). Conscious patients are usually given a medication to make them sleepy or unconscious and a muscle relaxant to help them relax while the tube is inserted.

Sometimes people may be ventilated for a short or a long time.

Noninvasive Positive Pressure Ventilation
Some patients may receive ventilation without needing intubation, with the breathing support being delivered via a sealed mask applied to the face. However noninvasive ventilation is useful only in some circumstances and in some patients.