Expired gas analysis of field simulated CPR

The concentration of expired oxygen and carbon dioxide that a rescuer may give during cardiopulmonary resuscitation was originally determined without adjusting for conditions that can exist in real life. This study was devised to investigate how simulated field conditions might effect the concentrations of these gases that a rescuer would give a victim. The expired gases were measured from volunteers who performed one person cardiopulmonary resuscitation on manikins for two minutes. They then stopped the resuscitation, walked or ran 200 meters, and performed another two minutes of cardiopulmonary resuscitation while listening to loud ambulance sirens. For the thirty-eight volunteers that were tested, it was found that the percentage of carbon dioxide increased by an average of 11% and the oxygen concentration only changed by a negligible amount. This amounted to a statistically significant increase in the carbon dioxide concentration (p << 0.01), without a significant change in the oxygen concentration (p > 0.05). In conclusion, exertion before performing CPR will cause an increase in the percent of CO2 expired, while not affecting the concentration of O2.