Progressive Care Nursing Certification (PCCN) Practice Exam

When plasma glucose falls to 250 mg/dL in acute diabetic ketoacidosis (DKA), what should IV fluids be changed to prevent?

1. Hyperglycemia

2. Hyperkalemia

3. Cerebral edema

4. The Somogyi effect

The correct answer is: Cerebral edema

When plasma glucose levels fall to 250 mg/dL during the treatment of acute diabetic ketoacidosis (DKA), transitioning to an appropriate IV fluid is crucial to prevent cerebral edema. This condition can arise from rapid changes in plasma osmolarity, particularly when glucose levels decrease too quickly. During DKA, significant changes in the body's fluid and electrolyte balance occur, and as insulin therapy is initiated, the glucose levels can drop rapidly. If fluids with a high glucose concentration are not used once the plasma glucose reaches around 250 mg/dL, there is a risk of shifting fluids back into the cells too quickly, which can lead to swelling of brain cells and consequently cerebral edema. Maintaining the correct fluid and electrolyte balance while managing the glucose levels is vital to avoid these complications. Adjusting the IV fluids to a solution that avoids rapid changes in osmolarity, such as switching to fluids that contain a lower glucose concentration or that are isotonic, helps mitigate this risk, thus protecting against cerebral edema.