Aim: In animal and human studies, measuring the pressure of end tidal carbon dioxide (P(ET)CO2) has been shown to be a practical non-invasive method that correlates well with the pulmonary blood flow and cardiac output (CO) generated during cardiopulmonary resuscitation (CPR). This study aims to compare mechanical active compression-decompression (ACD) CPR with standard CPR according to P(ET)CO2 among patients with out-of-hospital cardiac arrest (OHCA), during CPR and with standardised ventilation.
Methods: This prospective, on a cluster level, pseudo-randomised pilot trial took place in the Municipality of Göteborg. During a 2-year period, all patients aged >18 years suffering an out-of-hospital cardiac arrest (OHCA) of presumed cardiac etiology were enrolled. The present analysis included only tracheally intubated patients in whom P(ET)CO2 was measured for 15 min or until the detection of a pulse-giving rhythm.
Results: In all, 126 patients participated in the evaluation, 64 patients in the mechanical chest compression group and 62 patients in the control group. The group receiving mechanical ACD-CPR obtained the significantly highest P(ET)CO2 values according to the average (p=0.04), initial (p=0.01) and minimum (p=0.01) values. We found no significant difference according to the maximum value between groups.
Conclusion: In this hypothesis generating study mechanical ACD-CPR compared with manual CPR generated the highest initial, minimum and average value of P(ET)CO2. Whether these data can be repeated and furthermore be associated with an improved outcome after OHCA need to be confirmed in a large prospective randomised trial.