Peter A Stewart

Peter Stewart (1921-1993) was a Canadian physiologist who introduced an alternate approach to understanding acid base physiology.

His original article provided an introduction, but his quantitative physico-chemical approach was outlined in detail in his influential 1981 book, "How to Understand Acid-Base" (New York, Elsevier). This book has long been out of print, but Dutch physician Paul Elbers has now made it available online. A new edition of the book, including reviews on current applications in clinical medicine, is due for publication in 2008.

Many of the generally accepted concepts of hydrogen ion behaviour are viewed differently and indeed are often shown to be wrong! The Stewart approach provides a chemical insight into the complex chemical equilibrium system known as acid-base balance. The impact of the Stewart analysis has been slow in coming but there has been a recent resurgence in interest, particularly as this approach provides explanations for several areas which are otherwise difficult to understand (e.g., dilutional acidosis, acid-base disorders related to changes in plasma albumin concentration).

Peter was born in Winnipeg, Manitoba in 1921. He graduated with honours from the University of Manitoba in 1943. Post-graduate qualifications were obtained from the University of Minnesota: Master of Science in physics and mathematics in 1949, and a PhD in biophysics in 1951. In 1954, he took up a position as Associate Professor of Physiology, Physics and Biometry at Emory University. In 1965, he joined Brown University as Professor of Medical Science.

He retired to Orcas Island in the Strait of Juan de Fuca near Seattle in 1983, and died in 1993.