Scientific Breakthroughs From Siggaard–Andersen Nomogram To Latest Developed Graphical Tool Representation For Arterial Blood Gas (ABG) Interpretation

Abstract

Arterial Blood Gas (ABG) interpretation plays an immense role in critical care medicine. Various  approaches are available to interpret ABG data.  The most commonly used approaches are the  physiological approach using  the bicarbonate-carbon dioxide buffer system and the base excess approach developed by Astrup and Siggard Anderson. Physico-chemical approach is used to explain the causative mechanism of metabolic acid base disturbances. The graphical representation may serve as an useful tool for easier and quicker interpretation of  ABG data. But only few graph methods are proposed and devised for depicting the various respiratory and metabolic acid–base disturbances. They are used for teaching purposes only and  these are  not practically convenient to use in clinical settings.  Graphical methods for ABG interpretation like Siggaard-Andersen chart (S-A chart), Davenport or Bicarbonate-pH diagram and Grogono diagram are not used frequently in the clinical practice due to certain practical difficulties and providing inaccurate diagnosis in few of  the ABG data. A newer graphical method using 4 quadrant method was  constructed  and proposed by the current author.  The purpose of this review is to discuss in detail the construction, interpretation, advantages, clinical utility and the limitations of the various proposed graphical tools.