The 2010 AHA Guidelines for CPR and ECC have a major new Class I recommendation for use of quantitative waveform capnography for confirmation and monitoring of endotracheal (ET) tube placement. Real-time monitoring and optimization of CPR quality using physiologic parameters, such as partial pressure of end-tidal carbon dioxide (PEtCO2), are encouraged. The guidelines also recommend the use of capnography PEtCO2 values to monitor CPR quality, detect return of spontaneous circulation and guide vasopressor therapy during cardiac arrest (Class IIb).
In EMS circles, capnometry used to just be a tool for determining whether an ET tube was properly placed. It soon became the gold standard for this function. However, medical directors, educators and field crews in most EMS systems soon realized that capnography was a multi-purpose assessment tool.
Capnography is the only single-monitoring modality available to EMS crews that provides a visual reference to a patient’s ABCs in less than 15 seconds, with a normal waveform instantly telling us our patient’s airway is patent, they’re breathing, and they’re adequately perfusing.
Capnography also provides the only direct, non-invasive measure of ventilatory status available to EMS crews and offers the earliest indication of hypoventilation, respiratory depression and respiratory failure.
Most importantly, changes in the capnography waveform provide the earliest indication of apnea, upper airway obstruction and laryngospasm. A glance at the waveform by a trained provider allows them to instantly see a patient’s response to airway alignment maneuvers and further distinguish upper airway obstruction from laryngospasm. Providers can also easily recognize the curved waveform of obstructive lung disease, which indicates bronchospasm.
Capnography can also be used effectively to detect, assess and triage victims of chemical terrorism. It’s helpful as an assessment and triage tool because chemical agents are primarily absorbed through the skin and respiratory tract and have their greatest effect on the central nervous and respiratory systems.
Because EtCO2 waveforms and trends alert crews to worsening conditions and allow them to intervene much earlier to correct or reverse a critical condition, capnography is one of the most important EMS assessment tools that can be carried in a critical care toolkit for conscious and unconscious patients.
Pass this special supplement to December JEMS along to your personnel and ensure your crews are fully utilizing all the important capabilities offered by capnography.