Rosh Emergency Medicine Practice Test

What laboratory assessment is important in a patient suspected of having hyperglycemia due to diabetes-related ketoacidosis?

1. Bicarbonate

2. Potassium

3. C-reactive protein

4. Complete blood count

The correct answer is: Potassium

In the context of diabetes-related ketoacidosis (DKA), assessing potassium levels is critical. During DKA, the body undergoes significant metabolic changes, including the movement of potassium out of cells as a result of insulin deficiency and acidosis. This can lead to a falsely elevated serum potassium level because even if the serum level appears high, the total body potassium may actually be depleted. Monitoring potassium is essential for several reasons: first, hypokalemia can develop during treatment as insulin administration drives potassium back into cells; second, potassium levels are important to assess prior to initiating insulin therapy to avoid complications such as cardiac arrhythmias. Therefore, the potassium level is a vital part of the laboratory assessment for patients suspected of DKA, ensuring proper management and treatment of the condition. Other laboratory assessments such as bicarbonate levels can point to acid-base status, C-reactive protein can indicate inflammation, and a complete blood count helps assess for infection but do not provide as direct insight into the immediate management of electrolyte abnormalities that are critical in DKA. Thus, potassium assessment stands out as the most crucial.