Noninvasive assessment of gas exchange in the critically ill patient

A variety of technologies is available to noninvasively evaluate arterial oxygen saturation and partial pressure of serum oxygen (PaO2) and carbon dioxide (PaCO2) in the critically ill patient. These include pulse oximeters, transcutaneous monitoring devices, capnometry, and capnography. Understanding the technology, the clinical significance of the data, and the associated limitations is fundamental in optimizing patient assessment and management. Accordingly, critical care nurses have increasing responsibilities related to these aspects of patient care.