What does S/T mode on a BiPAP indicate?

S/T mode on a BiPAP (Bilevel Positive Airway Pressure) device stands for "Spontaneous/Timed" mode. In this mode, the machine provides pressure support for the patient while allowing them to initiate their own breaths. The patient determines the tidal volume during spontaneous breaths, which means they are fully capable of breathing independently, but the device offers assistance if needed.

This is particularly useful for patients who may have fluctuating levels of respiratory effort, as they can receive additional support automatically if their breathing falls below a certain rate. The timed component ensures that if the patient does not achieve a minimum number of breaths within a set duration, the machine delivers breaths automatically to maintain ventilation. Therefore, the correct choice highlights the collaborative effort between the patient's effort and the machine's assistance in achieving adequate ventilation.