End-Tidal Carbon Dioxide Monitoring

End-tidal carbon dioxide monitoring refers to the noninvasive measurement of exhaled carbon dioxide and is most useful when applied directly to patient care.¹ Although commonly used in intubated patients receiving mechanical ventilation, this technique is sometimes used in non-intubated patients.^2–,4 The term “capnometry” refers to the measurement and display of the concentration of exhaled carbon dioxide either as a percentage (%) or as partial pressure in millimeters of mercury (mm Hg). If the gas measuring device also includes a calibrated, visual waveform recording of the concentrations of inspired and exhaled carbon dioxide that can be examined on a breath-by-breath basis or for long-term trends, the instrument is called a capnograph.⁴ Although this respiratory monitoring technology is not new to the critical care environment, controversy still exists regarding potential benefits and limitations in clinical practice.⁵ The questions and answers presented here may enhance your understanding...