Understanding Acid-Base Disorders

The accurate interpretation of laboratory tests in patients with acid-base disorders is critical for understanding pathophysiology, making a diagnosis, planning effective treatment and monitoring progress. This is an important topic particularly for junior medical staff who may encounter acidbase problems outside normal working hours when patients become acutely unwell. These clinical situations may be a source of confusion particularly because of the variety of terms used to describe and classify acid-base disorders. In this article, we aim to provide the reader with an overview of the key concepts necessary for developing a good working understanding of acid-base disorders that commonly present in clinical medicine. We start with some acid-base disorder definitions and then provide a series of case vignettes to illustrate the key points.