<prompt> What is this instrument used for:VentilationFeedingTURPCholestomy  <response>: Ans. a VentilationRef.: Millers Anaesthesia 7th ed. 2139 AMBU Bag stands for Ambulatory Breathing Unit. It is a self-refilling bag-valve-mask unit with 1-1.5L capacity, used for ventilating and oxygenating intubated patients, allowing both spontaneous and artificial respiration. 