Capnography Monitoring

What Is Capnography Monitoring?

Capnography is the continuous, real-time measurement and waveform display of exhaled carbon dioxide (end-tidal CO2, or ETCO2), typically shown as a numeric value (normal range roughly 35–45 mmHg) alongside a graphical waveform on the monitor. It's considered the gold standard for confirming and continuously monitoring advanced airway placement, since a consistent square waveform confirms the tube is in the trachea and ventilating the lungs — unlike breath sounds or chest rise, capnography can't be faked by esophageal placement. Beyond airway confirmation, ETCO2 trends reflect ventilation adequacy, metabolic rate, and circulatory status, making it useful in cardiac arrest (rising ETCO2 during CPR can indicate improving perfusion, and a sudden spike often signals return of spontaneous circulation), COPD/asthma exacerbations (characteristic 'shark fin' waveform), and sedation monitoring.

Why Capnography Monitoring Matters on the Fireground

An undetected dislodged or misplaced advanced airway is one of the most preventable causes of patient harm in EMS, and waveform capnography is the single most reliable tool for catching it immediately, including during patient movement when tubes are most likely to shift. During cardiac arrest, capnography also helps gauge CPR quality and can be one of the earliest indicators of return of spontaneous circulation, directly informing resuscitation decisions in real time.

Relevant NFPA Standards

• AHA Guidelines: Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
• NFPA 455: Standard for Emergency Medical Services (EMS)

Field Procedures & Tactical Steps

1. Attach the capnography sensor immediately after placing an advanced airway, or via nasal cannula for non-intubated patients being monitored for ventilation status.
2. Confirm a consistent, normal-shaped waveform to verify correct airway placement before securing the device.
3. Monitor ETCO2 trends continuously — during cardiac arrest, watch for a sustained rise that may indicate improving perfusion or return of spontaneous circulation.
4. Reassess the waveform immediately after any patient movement to catch a dislodged or displaced airway.
5. Adjust ventilation rate or depth based on ETCO2 trends and document readings throughout the call for the patient care report.

Common Context & Application

Used continuously on any patient with an advanced airway to confirm and monitor placement, and increasingly applied via nasal cannula on non-intubated patients in respiratory distress, sedation, or overdose calls to track ventilation trends in real time.

Frequently Asked Questions about Capnography Monitoring