In cases of severe hyperglycemia associated with DKA, what metabolic disturbance is typically present?

In cases of severe hyperglycemia associated with diabetic ketoacidosis (DKA), severe acidosis is typically present due to the accumulation of ketoacids. DKA occurs as a result of insulin deficiency, leading to an increase in lipolysis and the subsequent production of ketone bodies such as acetoacetate and beta-hydroxybutyrate. These ketoacids contribute to the metabolic acidosis observed in DKA.

The body attempts to compensate for this acidosis through respiratory mechanisms (increased ventilation to blow off carbon dioxide) and renal mechanisms (excreting hydrogen ions and reabsorbing bicarbonate), but these compensatory mechanisms can become overwhelmed, especially in severe cases. As a result, patients present with metabolic acidosis on laboratory tests, characterized by a low arterial blood pH and low bicarbonate levels.

While other electrolyte disturbances, such as hyperkalemia, may occur in conjunction with DKA due to shifts in potassium distribution, the defining feature of the metabolic derangement in DKA is the presence of significant acidosis. Recognizing this acidosis is crucial for appropriate management and treatment of DKA.