A ventilation system, comprising: a ventilator comprising: a controller; a user output interconnected to the controller and configured to provide information to a user regarding the operational status of the ventilator; a user input interconnected to the controller for receiving user inputs related to controlling the operation of the ventilator; at least one sensor (138, 142) interconnected to the patient circuit; and a breathing gas supply interconnected to and operated in response to instructions from the controller; wherein the controller is configured to receive information regarding a flow of gas detected by the at least one sensor (138, 142) to thereby determine a connection status of a patient; a patient circuit interconnected to the breathing gas supply; and a patient breathing apparatus interconnected to the patient circuit; characterized in that the controller is configured to control the ventilator to: enter a disconnect mode and prompt a user to enter a safe standby mode when the controller detects that the user has been disconnected from the ventilator; determine whether the safe standby mode has been selected by the user; enter the safe standby mode if it is determined that the safe standby mode has been selected, wherein in a safe standby mode of operation ventilator settings are maintained and the connection status of the patient is monitored; and enter a normal ventilation mode when it is detected that the patient is reconnected to the ventilator while in the safe standby mode. a ventilator comprising: a controller; a user output interconnected to the controller and configured to provide information to a user regarding the operational status of the ventilator; a user input interconnected to the controller for receiving user inputs related to controlling the operation of the ventilator; at least one sensor (138, 142) interconnected to the patient circuit; and a breathing gas supply interconnected to and operated in response to instructions from the controller; wherein the controller is configured to receive information regarding a flow of gas detected by the at least one sensor (138, 142) to thereby determine a connection status of a patient; a controller; a user output interconnected to the controller and configured to provide information to a user regarding the operational status of the ventilator; a user input interconnected to the controller for receiving user inputs related to controlling the operation of the ventilator; at least one sensor (138, 142) interconnected to the patient circuit; and a breathing gas supply interconnected to and operated in response to instructions from the controller; a patient circuit interconnected to the breathing gas supply; and a patient breathing apparatus interconnected to the patient circuit; enter a disconnect mode and prompt a user to enter a safe standby mode when the controller detects that the user has been disconnected from the ventilator; determine whether the safe standby mode has been selected by the user; enter the safe standby mode if it is determined that the safe standby mode has been selected, wherein in a safe standby mode of operation ventilator settings are maintained and the connection status of the patient is monitored; and enter a normal ventilation mode when it is detected that the patient is reconnected to the ventilator while in the safe standby mode.