What type of information does capnography provide to the critical care team?

• A. Blood pressure trends
• B. Oxygen desaturation and graphic display of the breathing pattern and CO2 elimination
• C. Heart rate variability
• D. Glucose level trends

Answer: (B)

Capnography gives real-time information about ventilation by measuring CO2 in the air the patient exhale and displaying it as a capnogram. It shows the end-tidal CO2 value, which reflects how effectively the lungs are ventilating, and presents a continuous graphic waveform that tracks CO2 elimination with each breath. This visual pattern helps clinicians quickly identify changes in breathing: hypoventilation, hyperventilation, airway obstruction, apnea, or a loss of airway or circuit integrity. While it doesn’t directly measure oxygen saturation, capnography can signal ventilation problems that may lead to desaturation, making it a key tool for detecting evolving respiratory compromise. The essential usefulness lies in the graphic breathing pattern and CO2 elimination it provides, rather than measurements of blood pressure, heart rate variability, or glucose levels.