Also, according to the AHA, continuous waveform capnography along with clinical assessment is the most reliable method of confirming and monitoring correct placement of an ET tube.
What is Waveform Capnography
Quantitative waveform capnography is the continuous, noninvasive measurement and graphical display of end-tidal carbon dioxide/ETCO2 (also called PetCO2). Capnography uses a sample chamber/sensor placed for optimum evaluation of expired CO2. The inhaled and exhaled carbon dioxide is graphically displayed as a waveform on the monitor along with its corresponding numerical measurement.
As an assessment tool during CPR, capnography can help the ACLS provider determine a number of things. It is a direct measurement of ventilation in the lungs, and it also indirectly measures metabolism and circulation. For example, a decrease in perfusion (cardiac output) will lower the delivery of carbon dioxide to the lungs. This will cause a decrease in the ETCO2 (end-tidal CO2), and this will be observable on the waveform as well as with the numerical measurement.
Normal ETCO2 in the adult patient should be 35-45 mmHg.
Two very practical uses of waveform capnography in CPR are: 1.) evaluating the effectiveness of chest compressions, and 2.) identification of ROSC. Evaluating the effectiveness of chest compressions is accomplished in the following manner: Measurement of a low ETCO2 value (< 10 mmHg) during CPR in an intubated patient would indicate that the quality of chest compressions needs improvement.
High quality chest compressions are achieved when the ETCO2 value is at least 10-20 mmHg.
When ROSC occurs, There will be a significant increase in the ETCO2. (35-45 mmHg) This increase represents a drastic improvement in blood flow (more CO2 being dumped in the lungs by the circulation) which indicates circulation.
For the intubated patient in cardiac arrest, quantitative waveform capnography is now considered the desired method for monitoring the quality of chest compressions and determining when the patient has a ROSC.
This video explains waveform capnography, it benefits, and various applications.
Sheila Boswell says
Thank you Jeff, this is great information! Your site is so much more interesting than reading the manual.
Jeff with admin. says
You are welcome. I’m so glad that it is helpful. Kind regards, Jeff
jane1136 says
Thanks so much for this easy explanation!
Rawiya says
thank you it is beneficial
Russel_2k says
Excellent video.Easy to understand.Thank you so much!
Justyna8885 says
This is awesome! Easy to understand…finally!
Kristin says
Is there a “normal” EtCO2 reading immediately after ROSC? Would I see an immediate spike to WNL or will it take several minutes?
Jeff with admin. says
You should see a fairly quick change in the ETCO2 when ROSC is achieved. Steady improvement over 30-60 seconds would be expected.
Kind regards,
Jeff
Maneewan says
Jeff,
Thank you for the course, I passed with 100% written part. See you next time.
Cshirk says
Disappointed I could not view video on my IPad!
Jeff with admin. says
Check the link below the video for an iPad friendly version.
PR Do says
After reading all these comments , is there anyone who can comment on the accuracy of capnagraphy during CPR being performed with an extraglottic device such as an LMA or King LMA combitube. Since many out of hospital cardiac arrests arrive at our ED with these devises in place, with CPR in progress, it would be interesting to know.
Jeff with admin. says
I would say any airway device which is placed properly will give an accurate CO2 level. In turn, this would give you a good capnography reading. I think that the LMA or King LMA combitube when placed properly would give ETCO2 results.
In fact, ETC02 readings may help with better placement of these types of airways. Here is one study:
Kind regards,
Jeff
Kb says
Hey. Swedish medic here. Thanks for a great post. Follow up q regarding etco2 and Lma…in our protocol we are using a ratio of 30 comp. /2 vent during cpr when igel is placed. Can we still use the etco2 or is it only reliable when used in continuous compressions and 6-10 vent? Thanks for som input regarding This question.
Jeff with admin. says
This should still give you an accurate and reliable measurement of ETCO2.
Kind regards, Jeff
Margaret Mullin says
It is intuitive that increased velocity would account for increased EtCO2 and increased EtCO2 correlates with increased number of survivors. But I have some numbers that do not show this – can anyone speculate a reason why increased velocity is not correlated with improved survivor rate
ASC says
Need to know if these practice questions are similar to what is on the real ACLS test?.
Jeff with admin. says
All of the questions are developed from the AHA ACLS provider manual. They cover the content that you will see when you take the test. However, they are not the same questions as on the test. All of the practice questions are unique questions developed for this site.
Kind regards,
Jeff
Trina Acreman says
Is it possible to use capography with the BMV?
Jeff with admin. says
The BVM would probably give you inaccurate results if you were using the BVM over a capnography cannula. For best results during cardiac arrest, waveform capnography should be performed with an ET tube in place.
Kind regards,
Jeff
jennacleaveland says
How can you use waveform capnography to confirm ET tube placement during CPR. Would it look different than patients without an ET tube. Confused???
Jeff with admin. says
If an ET tube is not properly placed, you will not see the waveform that should be present as you administer breaths with a bag-vaulve-mask. It is that simple. No waveform=No proper intubation.
Once the tube is in its proper place, the ETCO2 will be able to be read, but until the ET tube is in place, you will not see the proper waveform that is seen when breaths are administered.
Kind regards,
Jeff
John says
Haven’t seen the video but have enjoyed this page. Btw, as an anesthesia doc who’s intubated more than ten, probably less than 20k patients, code intubations can be very challenging at times. Especially in an indulgent population (ours) with skyrocketing BMIs. Prepare for the worst and don’t waste time figuring out that you’re in trouble. Call for help early, it’s a sign of intelligence.
drsharini says
i agree! deferring moments are when sometimes you’re thought incompetent if you call for help. Sigh.. better safe than sorry the saying goes.
CCRNCENPHRN says
Personally I believe we should be placing supraglottic airways during arrests and then swapping them out for an ETT should ROSC occur. Most folks don’t intubate nearly enough, especially with chest compressions ongoing, to be skillful enough to keep pauses in compressions < 10sec. SALT airways are an option.
Suzanne Singer says
What website would you recommend that offers a clip viewing waveform capnography?
Laura says
capnography.com is a great start (covers the basics as well as how to troubleshoot some interesting waveforms). If you have access and the ability to pay for it, I just completed the physio-control university’s 5hr course on waveform capnography….very very VERY informative and helpful and provides you with CEs upon completion and passing an evaluation!