SUMMARY
Medical gases are known to show a great environmental impact and also to consume relevant resources in terms of hospital management. The present work reports on a study performed between 2008 and 2016 in a target set of 12 Spanish hospitals with floor area and number of beds ranging 2314–23,300 m2 and 20–194, respectively, for which the average annual consumption rates of oxygen, nitrogen, medicinal air, carbon dioxide and nitrogen protoxide were analysed. The annual consumption of medical gases in a hospital was proved to be correlated with the number of hospital discharges, the number of surgeries, the number of emergency interventions, the number of hospitalisations, the number of hospital beds, the useful floor area of the building and the number of workers. In particular, the annual consumption per hospital bed was computed as 350 m3 for oxygen, 325 m3 for medicinal air, 9 m3 for nitrogen protoxide and 3 m3 for carbon dioxide. It is shown that healthcare activity appears as an adequate variable to quantify and to monitor medical gases consumption in hospitals, to assess the size of their facilities as well as to optimise maintenance management.