The diagnosis and management of acid-base imbalance.

The ability to obtain an arterial blood gas analysis within a few minutes in most medical facilities enables the clinician to rapidly evaluate the acid-base status of his or her critically ill patients and to treat disorders as they appear. Although acid-base charts, graphs, and nomograms are available and can help to establish a diagnosis of acid-base disorders, the common practice is that most emergency and critical care clinicians tend to interpret acid-base data rapidly, usually without using any of these tools. The intent of this discussion is to provide the clinician with the pathophysiologic background of acid-base imbalance, the diagnostic criteria for acid-base disturbances, and the clinical approach to management. The standard arterial blood gas analysis, serum and urine electrolytes, and clinical assessment of the alveolar ventilation are the only data upon which this discussion is based.