Concentration and elimination of anaesthetic gases in recovery rooms.

The investigation includes measurement of the N2O-concentration in the recovery rooms of three hospitals with different room ventilation systems. The amount of ventilation determines the elimination of the gas exhaled by the patients and, therefore, is related to the number of patients in the recovery rooms. The investigation has shown that non-recirculating room ventilation of 500 m3/pt./hour in recovery rooms gives personnel the same protection against inhalation of anaesthetic gases as is afforded to personnel in operating theatres with scavening equipment.