Capnography

Most clinical systems use infrared spectroscopy to detect CO2 in exhaled gas. The instrument turns these measurements into a capnogram, so clinicians can view how the signal changes across the respiratory cycle rather than relying on a single reading. This continuous graphical output links the measured gas concentration with changing ventilation and respiratory status in real time.

The end-tidal CO2 value provides a numerical result, while the waveform displays how exhaled CO2 changes during breathing. Reviewing both helps clinicians recognize evolving changes in ventilation or gas exchange. This combination is useful when respiratory status may change quickly, including during anesthesia, sedation, airway management, and other monitored medical care.

Capnography can reveal ventilatory changes before intermittent oxygen or pulse measurements alone would prompt action. Its signal comes directly from exhaled CO2 and provides a continuous graphical view of the respiratory cycle. This rapid response makes the technique especially valuable for detecting hypoventilation or airway obstruction while a patient is being monitored.

Following tracheal tube placement, clinicians can observe the exhaled CO2 signal and review the capnogram as a real-time confirmation of airway placement. Detecting a consistent CO2 response supports assessment that the tube is positioned in the trachea. This application makes capnography an important monitoring step during airway management and anesthesia.

Anesthetic and sedative care requires close observation of ventilation and respiratory status. Capnography supplies a continuously updated CO2 value and waveform, allowing clinicians to notice changes while care is underway. In this setting, the method supports monitoring for hypoventilation or airway obstruction and may enable intervention sooner than intermittent measurements alone.

During resuscitation, the CO2 signal and capnogram offer a real-time way to assess respiratory changes rather than waiting for intermittent observations. Clinicians can follow the measured exhaled CO2 and waveform as the situation evolves, using that information to evaluate ventilation and gas exchange during ongoing resuscitative care.