In 1982 Poul Astrup, in writing a history of acid base balance and blood gases, invited me to contribute a chapter about the modern period, from 1950 to the present. Astrup’s book is scheduled for publication at the end of 1985 by Radiometer Company of Copenhagen; it will be distributed by Munksgaard (Blackwell). The story of blood gas analysis since 1950 is vast: there are some 420 references to methodology and closely related physiology. This “modern” history will appear in theJournal of Clinical Monitoring as a series of essays. This first essay centers on electrochemistry, the basis of modern blood gas analysis, and accordingly examines its roots in more detail.
The 17th and 18th century exploration of electricity and gas laws led to the development of thermodynamic electrochemistry in 1887 through the collaborative efforts of van’t Hoff. Arrhenius, Ostwald, and Nernst. The importance of the hydrogen ion in biology and in the body’s buffering mechanisms was worked out by Henderson, Van Slyke, Barcroft, and many others in the first quarterof this century. The glass electrode became available after 1925, but practical blood pH measurement was introduced in the 1950s by Astrup and Siggaard Andersen. Succeeding essays will concern micro pH methods and base excess analysis, the discoveries of Stow’s CO2 electrode and Clark’s O2 electrode, the development of oximetry, and related physiology.