BiPAP

= bi-level positive airways pressure

trade name for a device that provides ventilation for patients by delivering air to the lungs at two levels of pressure, either cyclically in an anaesthetized patient or triggered by the patient's attempts at breathing when awake. The higher pressure inflates the lungs to whatever volume can safely be achieved, while the lower pressure enables controlled exhalation against a resistance: this minimizes atelectasis, a risk with conventional positive-pressure ventilators, which allow exhalation against zero resistance (by opening a valve in the device). Although BiPAP is a trade name, it is now widely used generically for this type of ventilation (or ventilator). There are also other devices that utilize the same principle, for example vPAP (variable positive airways pressure).