Concepts of the strong ion difference applied to large volume resuscitation

The occurrence of acidosis following trauma or other clinical conditions th at require large volumes of resuscitation fluid may be modified by manipula tion of the physical chemistry properties of substances within plasma. Thes e include the strong ion difference, modification of hydrogen ion productio n through control of alveolar ventilation, and protection/provision of prot ein and phosphate-based weak acids. An understanding of these principles as an alternative method to analyze/anticipate acid-base abnormalities is imp ortant during resuscitation. Loss of protein-based weak acids may often occ ur after trauma or other conditions requiring large-volume resuscitation. T hese losses may potentially be replaced with albumin-based colloid solution s. Large quantities of normal saline should be avoided so as to avoid hyper chloremia-induced metabolic acidosis. Ringer's lactate solution is preferre d. Alveolar ventilation must be adjusted so as to eliminate further hydroge n ion production caused by hypercarbia. The serum base excess and/or hyperl actemia have only limited value in diagnosing acidosis and guiding resuscit ation. Current experimental data and reviews of this topic were obtained fr om a Medline literature search. In addition. the personal experience and in vestigations of the authors in critically ill and injured patients were use d to formulate recommendations.