3 Ways to Use End-Tidal Carbon Dioxide (ETCO2) in Emergency Resuscitation

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.

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.