This chapter deals with acid-base homeostasis with special emphasis on the role of the respiratory system. After explaining why maintaining a relatively constant proton activity is critical to optimal cellular function we define acid-base balance and describe the basic mechanisms responsible for acid-base homeostasis. After describing the unique role of the HCO3-/CO2 buffer pair in acid-base regulation the four primary acid-base disturbances are defined. Finally an extensive outline is presented of the various approaches for the evaluation of acid-base disorders followed by examples and a few clinical cases.
Keywords: Acid-Base Disorders, Acid-Base Homeostasis, Acidemia, Acidosis, Alkalemia, Alkalosis, Anion Gap, Base Excess, Buffering Capacity, Davenport Diagram, Henderson-Hasselbalch, Hydrogen Ions, Imidazole Group, Metabolic Acidosis, Metabolic Alkalosis, pH, pKa, Respiratory Acidosis, Respiratory Alkalosis, Standard Bicarbonate.