Progressive Care Nursing Certification (PCCN) Practice Exam

A patient with type II diabetes presents with a high serum glucose level and symptoms consistent with diabetic ketoacidosis (DKA). What lab finding should the nurse anticipate?

1. Negative urine ketones and an arterial pH of 7.42

2. Positive urine ketones and an arterial pH of 7.24

3. Negative urine ketones and an arterial pH of 7.35

4. Positive urine ketones and an arterial pH of 7.50

The correct answer is: Positive urine ketones and an arterial pH of 7.24

In the context of diabetic ketoacidosis (DKA), it is essential to understand the typical metabolic derangements that occur. DKA is characterized by a triad of findings: hyperglycemia (elevated serum glucose), ketosis (the presence of ketones), and acidosis (metabolic acidosis indicated by a low arterial pH). When a patient is in DKA, they often have positive urine ketones due to the body breaking down fat for energy in the absence of adequate insulin. This results in the production of ketone bodies that can be found in the urine. Additionally, the metabolic acidosis associated with DKA usually leads to a decreased arterial pH, typically below 7.30, indicating acidemia. The anticipated lab finding of a positive urine ketone and an arterial pH of 7.24 reflects the presence of ketosis and the acidosis characteristic of DKA. An arterial pH of 7.24 indicates a significant acidemia, aligning with the clinical picture of DKA. In summary, recognizing the association between positive urine ketones and low arterial pH is crucial in confirming a diagnosis of DKA and guiding further management in such patients.