INTRODUCTION
Extreme derangements in acid-base physiology are
common in intensive care unit patients and traditional
methods are often inadequate to explain this phenomenon
in some patients. To explain this extreme acid-base
derangement in intensive care unit patients, Stewart
proposed a quantitative biophysical approach.
1,2
According to Stewart, changes in hydrogen ion
concentration in plasma result from water dissociation.
3
The determinants of such dissociation can be reduced to
three factors – strong ion difference, partial pressure of
carbon dioxide, and weak acid concentration.
3
One of the
most important implications of Stewart’s analysis is the
role of chloride in acid-base homoeostasis. When
chloride increases and the sodium chloride difference