Anesthetic respiratory system

Claim 1

An anesthesia system for inhalation narcoses which is switchable from partial or total rebreathing to non-rebreathing modes of operation, comprising a ring line connected to a patient outlet forming an inspiration gas branch and an expiration gas branch, one-way valve means in each said inspiratory and expiratory branches for directing gas flow from said inspiratory gas branch to said patient connection and from said patient connection to said expiratory gas branch, a controllable outlet valve mounted in said expiration gas branch downstream of said one-way valve means, a CO 2 absorber mounted in said expiration branch downstream of said outlet valve, said expiration branch having spaced apart connection points, said CO 2 absorber having an inlet and an outlet detachably mounted to said connection points, one connection point being downstream of said absorber including a shut-off element including means positively actuated by the removal of said absorber from said ring line which thereby interrupts said ring line and establishes separate expiration and inspiration branches of said respiration line, said second point of connection of said absorber being opened upon removal of said absorber and being located upstream of said absorber and downstream of said controllable outlet valve, gas source means connected to said ring line downstream of said one connection point for providing an increased pressure in said ring line during an inspiratory phase and a decreased pressure during an exhalation phase, pressure relief valve means connected to said ring line downstream of said one connection point and means responsive to said increased pressure for closing said controllable outlet valve.