Skip to main content

Ever since The Joint Commission issued revised requirements on resuscitation in early 2022, more and more hospitals are starting to take a closer look at their Code Blue practices and ask some key questions. How are we currently supporting our Code Blue teams to perform at their best? What types of trainings, resources, and feedback should we incorporate to maximize performance? Are there new tools we should invest in, or existing ones that we’re not fully optimizing?

One such tool that often falls into the latter category: end-tidal carbon dioxide (ETCO2) monitoring. Despite being simple, noninvasive, and multi-purpose, it’s often overlooked and underutilized for in-hospital cardiac arrest. In this article, we’ll cover the basics of ETCO2 and why it’s worth measuring, plus highlight 3 ways it can be used during a Code Blue.

ETCO2 Basics

  • Measures the amount of carbon dioxide released at the end of an exhaled breath
  • Indicator of a patient’s metabolism, circulation, and ventilation1
  • Average reading for a healthy adult: 35-45 mmHg

Why measure ETCO2?

Clinicians can use ETCO2 to gauge patient status in all kinds of clinical scenarios. But the readings can be particularly valuable in a high-stakes event like cardiac arrest, where monitoring quality indicators is crucial to guide and inform care.

There are also some practical benefits to consider:

  • Easy and noninvasive: Waveform capnography measures ETCO2 continuously and portrays the readings visually as a waveform. Whether your hospital uses a handheld device, bedside monitor, or defibrillator attachment, these devices are simple and noninvasive. This means that there’s very little risk that use of the device will interfere with the code or add unnecessary burden to the team.
  • Worth the investment: Like anything else, these devices come with a cost. But since ETCO2 levels yield insight into patient status and can guide care in a critical, life-or-death event like cardiac arrest, the small investment of a monitoring device is well worth it.
  • Multi-purpose: Depending on the circumstances, ETCO2 readings can be used in more than one way during a code. From confirming correct placement of an endotracheal tube to helping clinicians recognize return of spontaneous circulation (ROSC), let’s take a closer look at the top 3 ways Code Blue responders can get the most out of this quality indicator.

1. Confirm endotracheal tube placement

Recommended by both the American Heart Association and the International Liaison Committee on Resuscitation,2 waveform capnography is the most reliable way to verify that an endotracheal tube is positioned correctly in the trachea. This is true not only for initial placement of the tube, but also for ongoing monitoring to ensure it doesn’t become dislodged during resuscitation. For instance, if no ETCO2 recordings are traced during cardiopulmonary resuscitation (CPR), it’s a signal to the team to re-evaluate the tube location.3

2. Monitor chest compression quality

Study after study has shown the importance of high-quality CPR, but it can prove challenging and elusive to even the most experienced clinicians. Manual CPR is both physically and mentally demanding, as responders strive to repeatedly execute compressions at the optimal depth and rate throughout the code.

ETCO2 monitoring doesn’t make the task itself any easier, but it does offer in-the-moment feedback about the team’s efforts. And since clinicians are often relying on muscle memory when performing CPR, the value of a real-time, objective measure of compression quality really can’t be overstated.4-5 During CPR, code teams are aiming for ETCO2 readings greater than 20 mmHg. Readings between 10-20 mmHg are acceptable, and anything less than 10 mmHg is associated with poor outcomes. 4, 6-7 These guidelines help code teams quickly assess the effectiveness of their efforts and make changes as needed.

For example, a notable dip in ETCO2 can indicate that a compressor is tiring, or that some other controllable factor is hindering compression quality. And if the patient’s reading is less than 10 mmHg, the team needs to make an adjustment to get back on track. In manual CPR, this could mean switching out a compressor. For teams using mechanical CPR, it’s a good idea to check to ensure the device is positioned correctly.

3. Identify ROSC

A sharp increase in ETCO2 — from the teens to around 40 mmHg, for example — is unlikely to be achieved through CPR alone and is a reliable sign of ROSC. Importantly, it’s often the earliest indicator of ROSC in a cardiac arrest patient, occurring before any other signs of life.8-9 This is particularly useful because response teams can identify ROSC as soon as it happens — versus waiting for the next pause in compressions to check for a pulse.10 Plus, it may help minimize delays and interruptions to CPR that can occur while response teams are feeling for a pulse.


Get code ready with CoDirector® Resuscitation Software from Nuvara®:

  • Keep up with the fast pace of the code using real-time electronic documentation
  • Accurately document every detail with a simple, intuitive user interface
  • Stay on track with dynamic software guidance based on ACLS algorithms
  • Receive immediate feedback with an auto-generated hot debrief report


  1. Duckworth, R. L. (2017). How to read and interpret end-tidal capnography waveforms. JEMS, 42(8).
  2. Soar, J., Berg, K. M., Andersen L. W., et. al. (2020). Adult Advanced Life Support 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation, 156 (2020): 85.
  3. Kodali, B. S. & Urman, R. D. (2014). Capnography during cardiopulmonary resuscitation: Current evidence and future directions. J Emerg Trauma Shock, 7(4): 332-340.
  4. Aminiahidashti, H., Shafiee S., Kiasari, A.Z., Sazgar, M. (2018). Applications of end-tidal carbon dioxide (ETCO2) monitoring in emergency department; a narrative review. Emergency, 6(1): 35.
  5. Morgenstern, J. (2020). The arrest trial – ecmo cpr. First10EM blog.
  6. Meaney PA, Bobrow BJ, Mancini ME, et al. (2013). Cardiopulmonary resuscitation quality: improving cardiac resuscitation outcomes both inside and outside the hospital: a consensus statement from the American Heart Association. Circulation. 128:421.
  7. Quantitative Waveform Capnography. Available at: Quantitative Waveform Capnography – ACLS Medical Training
  8. Noordergraaf, G., & De Vormer, A. (2020). Etco2 values during cpr: Your ventilation tempo matters. Resuscitation, 156, 260–262.
  9. Bhende, M. S., Karasic, D. G., & Karasic, R. B. (1996). End-tidal carbon dioxide changes during cardiopulmonary resuscitation after experimental asphyxial cardiac arrest. The American Journal of Emergency Medicine, 14(4), 349–350.
  10. Haines, L. E. Continuous wave-form capnography: A crucial tool for ED clinicians. American Nurse Today, 12(1).
The information provided in this article is strictly for the convenience of our customers and is for general informational purposes only. Publication by Nuvara does not constitute an endorsement. Nuvara does not warrant the accuracy or completeness of any information, text, graphics, links, or other items contained within this document. Nuvara does not guarantee you will achieve any specific results if you follow any advice in the document. It may be advisable for you to consult with a professional such as a lawyer, doctor, nurse, business advisor, or professional engineer to get specific advice that applies to your specific situation.