[The determination of end-expiratory CO2 during resuscitation. Experience and results with the Normocap 200 (Fa. Datex) in preclinical resuscitation conditions].

Capnometers measure carbon dioxide (CO2) in inspired and expired air. Under physiological conditions end-tidal CO2 (peCO2) measurements closely reflect arterial pCO2 (paCO2). End-tidal CO2 concentration has been found to correlate with cardiac output in animal models and in clinical studies with cardiac arrest during cardiopulmonary resuscitation (CPR). In the present study in 23 cases of CPR end-tidal CO2 concentrations were registered during precordial compression with a transportable, battery-carried capnometer. In 7 cases of successful CPR mean concentrations of end-tidal CO2 were higher than in unsuccessful CPR (13 +/- 7 mmHg versus 8 +/- 6 mmHg). No statistical significance was found. In case of successful CPR there was a sudden rise in end-tidal CO2 up to 54 +/- 6 mmHg, indicating satisfactory spontaneous circulation. With capnometry it is possible to assess the efficacy of precordial compression during resuscitation and the return of spontaneous circulation in cardiopulmonary arrest.