Blood gas measurement

The adequacy of gas exchange in the lung is reflected in the partial pressures of the respiratory gases in the blood. The accurate measurement of these partial pressures is of fundamental importance in the diagnosis and treatment of cardiopulmonary disorders, and can determine the course of treatment for the severely ill patient. The main thrust of this review focuses on the important measurements of the partial pressures of oxygen and carbon dioxide, written respectively as P(O 2 ) and P(CO 2 ) although inert and anaesthetic gases are also considered. Topics covered include: electrochemical sensors; gas chromatography; optical fluorescence techniques; the electrochemical titration technique; and mass spectrometry.