Combining the physical-chemical approach with standard base excess to understand the compensation of respiratory acid-base derangements: an individual participant meta-analysis approach to data from multiple canine and human experiments.

The bicarbonate adaptation that follows primary respiratory alterations is associated with variations of strong ion difference. In the acute phase, the variation in strong ion difference is mainly due to sodium variations and is not paralleled by modifications of standard base excess. In the chronic setting, strong ion difference changes are due to chloride variations and are mirrored by standard base excess.