During CPR, what change in ETCO2 should the therapist anticipate?

During CPR, the end-tidal carbon dioxide (ETCO2) level is expected to increase. This increase occurs due to the return of some blood flow and cardiac output to the lungs, even during chest compressions. As compressions are administered, the heart has a chance to pump blood, albeit not effectively or fully; this leads to a rise in the amount of carbon dioxide being transported to the lungs for exhalation.

Initially, ETCO2 levels can drop if compressions are not effectively circulating blood, but with high-quality CPR, there is a gradual increase in ETCO2 as perfusion improves. This is an important indicator that can signal the effectiveness of CPR being performed and can help evaluate the patient's response to resuscitation efforts.

Monitoring ETCO2 is often used as a tool to gauge the quality of CPR and ensure that adequate ventilation and perfusion are occurring. Thus, a rise in ETCO2 during CPR signals that the administered interventions are starting to have a positive impact on the carbon dioxide exchange process.