EMS Patient Monitoring - Capnography 2

The choice of monitoring device depends on factors such as the patient's condition, the level of invasiveness required, and the specific clinical scenario.

Mainstream and sidestream capnography are the most commonly used methods for continuous ETCO2 monitoring.

The devices used to measure end-tidal CO2 (ETCO2) typically include:

Capnometers: These are basic devices that measure and display the numerical value of ETCO2. They are commonly used in various medical settings.

Capnographs: More advanced devices that not only display the numerical value of ETCO2 but also provide a continuous graphical representation known as the capnogram.

The capnogram displays the CO2 concentration over time, showing inhalation, exhalation, and the phase where little or no CO2 is present (representing the end-tidal point).

Mainstream Capnography: With mainstream capnography, the sensor is placed directly in the patient's airway, usually at the end of an endotracheal tube or an adapter connected to a ventilation device.

This type of capnography provides immediate and accurate measurements but may add dead space to the breathing circuit.

Sidestream Capnography: With sidestream capnography, a sampling tube diverts a small portion of the patient's exhaled air to a separate sensor away from the patient.

This method is less invasive and reduces the dead space in the breathing circuit. It is commonly used in non-intubated patients and during procedural sedation.

Colorimetric Devices: These devices provide a color change based on the CO2 concentration. They are often used as a quick and cost-effective method for verifying endotracheal tube placement but may not provide continuous monitoring.

Portable Capnography Devices: There are compact and portable capnography devices designed for prehospital and emergency use by EMS providers. These devices are lightweight, battery-operated, and provide essential monitoring capabilities in various environments.

Further Reading:

Capnography: Principles and Practice by Michael K. Copeland

Capnography, King of the ABC’s: A Systematic Approach for Paramedics" by Troy Valente

Infinium (ND) What is a Capnograph https://infiniummedical.com/what-is-capnography/ Accessed January 16, 2024

Paramedic Care: Principles & Practice" by Bryan E. Bledsoe, Robert S. Porter, and Richard A. Cherry