Which of the following best describes capnography?

Capnography is specifically defined as a process for measuring the concentration of expired carbon dioxide in the breath. This technique provides critical information about a patient’s respiratory status and metabolic function. It allows healthcare providers to monitor how effectively carbon dioxide is being eliminated from the body during exhalation, which can indicate a variety of conditions affecting respiratory function, such as hypoventilation or ventilation-perfusion mismatch.

The use of capnography is particularly useful in emergency settings, where it can help assess the effectiveness of ventilation, especially in patients with altered consciousness, respiratory distress, or during sedation and intubation procedures. Accurate monitoring of carbon dioxide levels can also indicate the appropriateness of resuscitation efforts or the effectiveness of treatments for respiratory conditions.

In contrast, measuring heart rate, assessing blood pressure, or evaluating breath sounds are entirely separate physiological assessments and do not involve the measurement of carbon dioxide. Each of these parameters provides different insights into a patient's condition, but capnography is uniquely focused on carbon dioxide monitoring, making it a vital tool in emergency care.