Arterial blood gas changes during cardiac arrest and cardiopulmonary resuscitation combined with passive oxygenation/ventilation: a METI HPS study

Abstract

Objective High-fidelity simulators can simulate physiological responses to medical interventions. The dynamics of the partial arterial pressure of oxygen (P a O 2 ), partial arterial pressure of carbon dioxide (P a CO 2 ), and oxygen pulse saturation (SpO 2 ) during simulated cardiopulmonary resuscitation (CPR) were observed and compared with the results from the literature. Methods Three periods of cardiac arrest were simulated using the METI Human Patient Simulator™ (Medical Education Technologies, Inc., Sarasota, FL, USA): cardiac arrest, chest compression - only CPR, and chest compression - only CPR with continuous flow insufflation of oxygen (CFIO). Results In the first period, the observed values remained constant. In the second period, P a CO 2 started to rise and peaked at 63.5 mmHg. In the CFIO period, P a CO 2 slightly fell. P a O 2 and S p O 2 declined only in the second period, reaching their lowest values of 44 mmHg and 70%, respectively. In the CFIO period, P a O 2 began to rise and peaked at 614 mmHg. S p O 2 exceeded 94% after 2 minutes of CFIO. Conclusions The METI Human Patient Simulator™ accurately simulated the dynamics of changes in P a CO 2 . Use of this METI oxygenation model has some limitations because the simulated levels of P a O 2 and S p O 2 during cardiac arrest correlate poorly with the results from published studies.