Acid-base disturbances: an emergency department approach

Acid-base disturbances are physiological responses to a wide variety of underlying conditions and critical illnesses. Homeostasis of acid-base physiology is complex and interdependent with the function of the lungs, kidneys, and endogenous buffer systems. Traditionally, these disturbances have been classified in terms of being caused by either a primary respiratory or a metabolic insult and by chronicity and compensation. While existing literature consists largely of physiology reviews, several well-designed studies and clinical practice guidelines provide relevant new perspectives on interpreting and managing acid-base disturbances. This review outlines several approaches to characterizing disturbances, with a case-based format and algorithms to aid in diagnostic testing and interpretation of arterial blood gases.