Removal of scavenger reservoir bag

The scavenger reservoir bag is removed to prevent backpressure in the breathing circuit during long-term use of an anesthesia machine ventilator if no anesthetic agents are employed.
(A) The vacuum hose has already been removed from its connection to the scavenger system, just above where the had is turning the vacuum flow control knob.
(B) The finger is pointing to the reservoir bag. This bag must be removed when using a closed scavenger system with no active vacuum, in order to prevent backpressure to the breathing system.
(C) The reservoir bag is being removed, thereby allowing exhaust gas from the breathing circuit to flow into the room.