Systems and methods for monitoring respiratory gases

A device configured for monitoring a concentration of at least one volatile breathing compound in respiratory gases of patients, the device comprising:

• a patient respiratory gas interface comprising a mouthpiece for the patient to blow a respiratory gas into;
• a connector adapted to couple the patient respiratory gas interface to a gas conduit, the gas conduit leading the respiratory gas through a flow meter and a valve, wherein the flow meter configured to measure a predefined first flux level of a patient respiratory gas flux, wherein the gas conduit is configured to further lead the patient respiratory gas through an inlet into an intermediate gas storage having a winding inner volume, wherein the intermediate gas storage is open-ended via an exhaust outlet to let patient respiratory gas exhausts in excess of a volume of the intermediate gas storage out of the same in response to the flow meter sensing an expiration of the patient respiratory gas flux;
• and
• a pump configured to draw the patient respiratory gas with a predefined second flux level in a reverse direction out of a sampling gas outlet of the intermediate gas storage and into a gas sampling line, wherein exhaled concentrations of the at least one volatile breathing compound are determined by corresponding at least one volatile breathing compound detector.