An anesthesia ventilator, for the automated ventilation of a patient, includes an expiratory port and an inspiratory port for connecting a ventilation tube facing the patient for a breathing gas, a breathing gas delivery unit, at least one breathing gas sensor for detecting an anesthetic gas concentration, at least one pressure sensor for detecting a pressure of the breathing gas, as well as at least one computer. The computer is configured to actuate the breathing gas delivery unit as a function of the detected pressure of a preset desired pressure value. The computer is further configured to perform an adaptation of the desired pressure value as a function of the detected anesthetic gas concentration.