Which statement about capnography during CPR is true?

Which statement about capnography during CPR is true?

• A. It measures airway patency
• B. It provides a real-time measure of CPR quality and perfusion; EtCO2 >10-20 mmHg suggests better perfusion; a sudden rise to baseline may indicate ROSC
• C. It monitors blood pressure
• D. It tracks heart rate

Answer: (B)

Capnography during CPR provides a real-time readout of how well chest compressions are generating pulmonary blood flow, since end-tidal CO2 reflects the amount of CO2 being delivered to and exhaled from the lungs. When the end-tidal CO2 is above roughly 10–20 mmHg, it suggests better perfusion during compressions and a higher likelihood of successful resuscitation. A sudden rise in EtCO2 toward normal, baseline levels is a strong sign that spontaneous circulation has returned, because native cardiac output increases CO2 delivery to the lungs. Capnography helps in this context by linking the effectiveness of compressions to perfusion. It does not directly measure airway patency, blood pressure, or heart rate; those require other monitoring methods.

Capnography during CPR provides a real-time readout of how well chest compressions are generating pulmonary blood flow, since end-tidal CO2 reflects the amount of CO2 being delivered to and exhaled from the lungs. When the end-tidal CO2 is above roughly 10–20 mmHg, it suggests better perfusion during compressions and a higher likelihood of successful resuscitation. A sudden rise in EtCO2 toward normal, baseline levels is a strong sign that spontaneous circulation has returned, because native cardiac output increases CO2 delivery to the lungs. Capnography helps in this context by linking the effectiveness of compressions to perfusion. It does not directly measure airway patency, blood pressure, or heart rate; those require other monitoring methods.