APPARATUS AND METHOD FOR CONTINUOUS MONITORING OF TISSUE CARBON DIOXIDE AND pH USING CAPNOMETRIC RECIRCULATING GAS TONOMETRY

摘要

A tonometry catheter apparatus comprising an elongate flexible tube (10) having a proximal extracorporeal end and a distal interacorporeal end (24). The distal end (24) of the tube (10) has a distensible, gas-permeable tonometry vessel (14), the vessel (14) and the distal end (24) defining therebetween a space which may be filled with a gas. An in-flow lumen with a distal end and a proximal end is also provided, the distal end being in communication with the in-flow orifice (20). An out-flow lumen is disposed with a distal end and a proximal end, the distal end being in communication with the out-flow orifice (22). A capnometer and a sensor (32) quantify the level of carbon dioxide (CO2) gas exiting the vessel (14). A hollow connecting member defines with the vessel (14), the in-flow lumen and the out-flow lumen a closed path through which the gas may continuously recirculate.