Bi-level ventilation, also called BiPAP ventilation, is a noninvasive treatment that uses air flowing through a face mask to keep the airways open. Bi-level ventilators work by automatically adjusting the flow of air when a patient is inhaling and exhaling. Airflow is reduced during the exhale, making it easier for the patient to breathe normally while on the ventilator. This differs from ventilators that deliver a constant airflow pressure without adjustment.

Bi-level ventilation can be used to treat conditions such as sleep apnea, including central sleep apnea in children. Depending on the specific patient's needs, bi-level may be preferred over continuous ventilation. It is better than continuous ventilation at treating certain conditions and is more easily tolerated by some people.

Bi-level ventilation is noninvasive, which means the patient will usually wear a face mask that covers the nose and/or mouth. The mask creates a seal over these areas to make the air flow more easily into the nose. The face mask is usually connected to the ventilator by tubing.

Noninvasive ventilation is most often used for patients who have some ability to breathe on their own or can go for periods of time without using the machine. Invasive ventilation is given through a tracheotomy tube inserted directly into a patient's throat. This type of ventilation is usually appropriate for patients who are unable to breathe on their own and will need the ventilator permanently.

Bi-level ventilation can be used to treat sleep apnea, a condition in which the throat tissue relaxes while a person is sleeping and causes snoring and periods of oxygen deprivation. If not treated, sleep apnea can lead to more serious conditions, including stroke and heart attack. Bi-level machines treat sleep apnea by using airflow to keep the throat open.

A person diagnosed with mild sleep apnea may initially be given a CPAP machine, which produces a constant level of airflow. If he or she has trouble adjusting to the CPAP machine, a bi-level option may be used instead. Bi-level ventilation may also be effective in treating more severe cases of sleep apnea.

For problems such as central sleep apnea in children, bi-level ventilation may be the most effective treatment. Central sleep apnea is a condition in which the brain may temporarily stop sending signals to the muscles that control breathing. This causes breathing to stop periodically during sleep. Central sleep apnea can be a symptom of brain damage or other illnesses.