Anesthesia apparatus adapted for operating in one of a gas-dispensing mode and a gas-less simulation mode, and method of operating theanesthesia apparatus. A mode selection command is received from an input /output unit of the anesthesia apparatus. A control unit of the anesthesiaapparatusselects one of a gas-dispensing mode and a gas-less simulation mode based onthe received mode selection command. At least one gas control parameter isreceived from the input / output unit. When the gas-dispensing mode isselected,the control unit actuates gas dispensing means of the anesthesia apparatusbasedon the received at least one gas control parameter. When the gas-lesssimulationmode is selected, the control unit prevents actuation of the gas dispensingmeans,and transmits the at least one gas control parameter to a patient simulationsystemvia a communication interface of the input / output unit.
