In the era of lung-protective forms of ventilation, ventilation efficiency can be optimized through targeted measurements of the dead space to tidal volume ratio. Capnography, as a graphical representation of expiratory CO2 concentration, is an essential component of bedside monitoring of ventilated patients. Capnography represents CO2 kinetics non-invasively and in real time. As part of the daily routine, it can be used to identify the correct intubation and adjust the minute volume of air to be delivered. However, capnography, particularly in its volumetric form, which is not yet widely used in hospitals, can provide much more extensive and clinically valuable additional information. These include the monitoring and optimization of ventilation, and the assessment of gas exchange. This provides the care team with clinical parameters for bedside decision-making which, until now, could only be obtained by more complex, invasive and non-automated procedures.