What is the importance of capnography in monitoring ventilation?

Capnography is a critical tool in monitoring ventilation because it measures the concentration of carbon dioxide (CO2) in exhaled air. This measurement provides real-time information about a patient's ventilatory status. During the process of respiration, CO2 is produced by metabolism in the tissues and transported in the blood to the lungs for exhalation. By assessing the levels of CO2 expelled during exhalation, capnography allows healthcare providers to evaluate how well a patient is ventilating.

An increase in CO2 levels can indicate hypoventilation, where not enough CO2 is being expelled, while a decrease can suggest hyperventilation or insufficient metabolic production of CO2. Therefore, capnography serves as a reliable indicator of both the effectiveness of ventilation and the adequacy of respiratory function.

Other options offered in the question do not serve the same purpose as capnography. Monitoring heart rate during exhalation is not the primary function of capnography, nor does the device measure oxygen levels in inhaled air or directly assess the efficiency of oxygen delivery to tissues. Instead, it focuses specifically on the measurement of carbon dioxide as a reflection of ventilation adequacy.