ETCO2 MONITORING DURING LOW-FLOW STATES - CLINICAL AIMS AND LIMITS

End-tidal carbon dioxide concentration in the expired air (ETCO2) is m easured with different technologies. ETCO2 allows the global evaluatio n of three main body functions: metabolism, circulation and ventilatio n. If two of these parameters are held constant, changes in ETCO2 refl ect a variation of the third. Thus, ETCO2 is now widely used as a reli able monitoring device in various clinical settings. In the past years several studies proposed ETCO2 as a non-invasive monitor for the eval uation of therapeutic efforts during low-flow states, and especially d uring cardiopulmonary resuscitation. However, recent laboratory and cl inical investigations demonstrated that various pharmacological and ph ysical interventions may influence ETCO2. Especially, the use of the C O2 generating buffer NaHCO3 increase and alpha-adrenergic agents const antly decrease ETCO2. Thus, although ETCO2 remains a necessary tool du ring anaesthesia, it may loose the potential for prediction of surviva l when monitoring the resuscitative efforts during cardiopulmonary res uscitation.