A nurse is caring for a client who has type 1 diabetes mellitus. The nurse misread the client's morning blood glucose level as 210 mg/dl instead of 120 mg/dL and administered the insulin dose appropriate for a reading over 200 mg/dL before the client's breakfast. Which of the following actions is the nurse's priority?

Rationale: A. Notify the nurse manager: Informing the nurse manager is necessary to follow institutional policy after a medication error. However, this does not directly address the client’s immediate physiological risk of developing hypoglycemia from the excess insulin. B. Monitor the client for hypoglycemia: The priority action is to closely observe the client for hypoglycemia, since too much insulin was given for the actual glucose level. Monitoring allows early recognition of symptoms such as sweating, tremors, or confusion so that treatment can be initiated promptly. C. Complete an incident report: Documenting the error in an incident report is required for safety and quality improvement. However, this is a secondary action and does not protect the client from the urgent effects of potential hypoglycemia. D. Give the client 15 to 20 g of carbohydrate: Administering carbohydrates is appropriate only if the client shows symptoms of hypoglycemia. Preventive administration without evidence may lead to unnecessary hyperglycemia, so monitoring is the safer first step.