Respiratory aid apparatus comprising: - a motorised micro-blower or a gas supply device (41, 55) comprising an inhalation valve, - a gas circuit (2, 16) with at least one inhalation limb able to transport a respiratory gas to be administered to a patient in cardiac arrest during a cardiopulmonary resuscitation, - measurement means able and designed to: i) measure at least one parameter representative of said gas flow, ii) convert said at least one parameter representative of said gas flow into at least one signal representative of said gas flow, - and signal processing and control means (5, 8) able and designed to: a) process said at least one signal representative of the gas flow provided by the measurement means and b) deduce from said at least one signal representative of the gas flow, an information relating to a cardiac massage being performed on the patient in cardiac arrest, characterised in that the signal processing and control means (5, 8) are configured to control the motorised micro-blower or the inhalation valve so as to: i) in response to the detection of a compression phase, increase the volume or gas pressure provided by the motorised micro-blower or the inhalation valve, and ii) in response to the detection of a release/decompression phase, reduce the volume or gas pressure provided by the motorised micro-blower or the inhalation valve. - a motorised micro-blower or a gas supply device (41, 55) comprising an inhalation valve, - a gas circuit (2, 16) with at least one inhalation limb able to transport a respiratory gas to be administered to a patient in cardiac arrest during a cardiopulmonary resuscitation, - measurement means able and designed to: i) measure at least one parameter representative of said gas flow, ii) convert said at least one parameter representative of said gas flow into at least one signal representative of said gas flow, i) measure at least one parameter representative of said gas flow, ii) convert said at least one parameter representative of said gas flow into at least one signal representative of said gas flow, - and signal processing and control means (5, 8) able and designed to: a) process said at least one signal representative of the gas flow provided by the measurement means and b) deduce from said at least one signal representative of the gas flow, an information relating to a cardiac massage being performed on the patient in cardiac arrest, characterised in that the signal processing and control means (5, 8) are configured to control the motorised micro-blower or the inhalation valve so as to: i) in response to the detection of a compression phase, increase the volume or gas pressure provided by the motorised micro-blower or the inhalation valve, and ii) in response to the detection of a release/decompression phase, reduce the volume or gas pressure provided by the motorised micro-blower or the inhalation valve. a) process said at least one signal representative of the gas flow provided by the measurement means and b) deduce from said at least one signal representative of the gas flow, an information relating to a cardiac massage being performed on the patient in cardiac arrest, i) in response to the detection of a compression phase, increase the volume or gas pressure provided by the motorised micro-blower or the inhalation valve, and ii) in response to the detection of a release/decompression phase, reduce the volume or gas pressure provided by the motorised micro-blower or the inhalation valve.