Using Waveform Capnography in Cardiac Arrest

Let’s talk for a moment about one of the latest and greatest tools recommended to be used in cardiac arrest….Waveform Capnography.

Waveform capnography measures the CO2 in our patients. This is the other side of the of pulse oximetry. When we monitor and compare both at the same time, it let’s us see the whole picture so we can better manage our patients.

What does capnography measure?

During cardiac arrest, waveform capnography measures 3 things for us.

1. Intubation. This is the most definitive way of knowing whether an intubation was successful. Other means such as listening over the epigastric region and lungs, checking tube fog, and x-rays are also necessary and still indicated. However, if you are seeing waveform, you know you did it right.
2. Ventilations. You can tell according to your waveform readings whether you are hyperventilating or hypoventilating your patient. We’ll explain more below.
3. Compressions. Waveform capnography directly correlates to the quality of your compressions. If the quality starts going down, so will your capnography numbers.

What numbers are we looking for?

1. During cardiac arrest – >10mmHg.
2. R.O.S.C. (return or spontaneous circulation) – immediate spike to around 50mmHg
3. Post-R.O.S.C. – 35-40mmHg

If you see less than 10mmHg during cardiac arrest, you need to check your intubation, ventilations, and compressions.

The great thing about waveform capnography is that it let’s you see when your patient hits ROSC during your cycles of CPR. You don’t have to wait for the end of your 2 minutes like you do for performing a pulse check. Also, there’s no long periods of time feeling around for a weak/thready pulse. If your patient goes into ROSC, you’ll see a spike in your waveform whether you can feel a pulse or not.

You can watch our video on Waveform Capnography in Cardiac Arrest. Please leave comments and questions. Don’t forget to follow us.