An ETCO2 reading of 15 mmHg or higher indicates what during ALS?

• A. Adequate forward movement of blood
• B. Adequate ventilation
• C. ROSC
• D. Poor perfusion

Answer: (A)

ETCO2 during CPR mainly reflects pulmonary perfusion and cardiac output, not just ventilation. When chest compressions generate enough forward blood flow, CO2-rich blood is delivered to the lungs and expelled, raising the ETCO2. A level around 15 mmHg or higher suggests there is adequate forward blood movement through the circulation, meaning CPR is effectively generating cardiac output. It’s a sign of perfusion produced by compressions rather than a guarantee of ROSC, and it’s not simply about ventilation, which could be high or low independent of perfusion.