Which ETCO2 change is commonly associated with ROSC?

• A. A sustained increase in EtCO2 toward baseline or higher
• B. A sudden drop to zero
• C. A oscillating EtCO2 with chest compressions
• D. No change

Answer: (A)

EtCO2 reflects how well blood is being circulated to the lungs and how effectively CO2 is being eliminated. When CPR is ongoing, chest compressions generate forward blood flow, so EtCO2 can rise modestly as perfusion improves. If ROSC occurs, cardiac output jumps up significantly, delivering more CO2 to the lungs and increasing the amount exhaled. That makes EtCO2 climb toward the patient’s baseline value or even higher, and the rise tends to be sustained. A sudden drop to zero would mean no pulmonary blood flow, which isn’t what ROSC looks like. An oscillating EtCO2 pattern can occur during ongoing compressions, but that’s not the sustained rise seen with ROSC. No change would imply no improvement in circulation. So, a sustained increase in EtCO2 toward baseline or higher best indicates ROSC.