A respiration system includes a patient connection (1), an inspiratory branch (3), an expiratory branch (13), a rebreathing line (99), a reservoir (25), a CO2 absorber (29), a radial compressor respiration drive (33), a fresh gas supply unit (51), an oxygen flushing device (55), connected to the rebreathing line, a pressure sensor (31) and an actuatable control valve (21), arranged in the rebreathing line between a second end (17) of the expiratory branch and the CO2 absorber. The compressor, oxygen flushing device and fresh gas supply unit are arranged in the rebreathing line between the CO2 absorber and a second end (7) of the inspiration branch. The compressor inlet points towards the CO2 absorber and the outlet points towards the second end of the inspiratory branch. The pressure sensor is arranged in the rebreathing line between the compressor and the second end of the inspiratory branch.
