Which sign is most characteristic of diabetic ketoacidosis (DKA)?

• A. Dehydration
• B. Kussmaul respirations
• C. Fruity breath
• D. Varying degrees of unresponsiveness

Answer: (B)

Metabolic acidosis from diabetic ketoacidosis triggers the body's need to blow off acid, so ventilation increases to raise pH. This compensation takes the form of deep, labored, rapid breathing known as Kussmaul respirations. That distinctive breathing pattern directly reflects the acid-base disturbance of DKA, making it the most characteristic sign. Dehydration is common but nonspecific—it can occur with many illnesses. Fruity breath can appear due to acetone, but not all patients with DKA have a noticeable odor. Unresponsiveness may occur in severe cases, but it isn’t the defining feature of the early presentation. So the presence of deep, laboring breathing best signals the underlying metabolic acidosis of DKA.