Siggaard-Andersen and the "Great Trans-Atlantic Acid-Base Debate".

In the late 1950's, while working with Poul Astrup's equilibration method of blood gas analysis, Siggaard-Andersen introduced a new parameter called base excess (BE) to quantify the non-respiratory acid-base imbalance. "The Great-Transatlantic Acid-Base Debate" arose when the "Boston" school, whose bicarbonate based analysis had been developed during pre-1950 Van Slyke days, (initially) argued that BE was not independent of PCO2 in vivo. Although Siggaard-Andersen and others then introduced a standard BE independent of PCO2, the Boston and Copenhagen schools are "unreconciled". While SBE is now used by most physicians, teaching and interpretation of acid-base chemistry remains confusing, "Boston" school laboratories refusing to report SBE, their students being asked to learn the 6 bicarbonate equations and rules, an old concept being reintroduced as "strong ion difference", or SID, and some wanting to discard pH in favor of nanomoles of H+, and end the era of "Arrhenius, Severinghaus and Henderson-Hasselbalch".