A patient with hepatic encephalopathy is receiving lactulose.
Which assessment provides the nurse with the best information to evaluate the patient’s therapeutic response to the drug?

The correct answer is D. Immediately after completion of the IV dose and 30 minutes before the next administration of the medication.

Explanation:

• Peak levels measure the highest concentration of the drug in the bloodstream, typically drawn immediately after completion of the infusion.

• Trough levels measure the lowest concentration, typically drawn 30 minutes before the next scheduled dose to ensure effective drug levels while preventing toxicity.

Why the other options are incorrect:

• A. One hour after completion of the IV dose and one hour before the next administration – Waiting one hour for the peak level could lead to an inaccurate measurement, as the drug may already be metabolized or distributed.

• B. Two hours after completion of the IV dose and two hours before the next administration – This timing is too late for both peak and trough levels, missing the best points for measurement.

• C. Thirty minutes into the administration of the IV dose and 30 minutes before the next administration – The sample drawn mid-infusion does not represent peak levels, making this method ineffective.

Key takeaway:

Peak and trough monitoring for vancomycin is essential to maximize effectiveness while avoiding nephrotoxicity and ototoxicity. Proper timing ensures accurate therapeutic drug monitoring.

Choice A rationale

Administering glucagon intramuscularly is typically done in response to severe hypoglycemia, not for symptoms of confusion and blurred vision which are side effects of glipizide. Glucagon works by triggering the liver to release stored glucose into the bloodstream, which would not be beneficial in this case as the client’s symptoms suggest hypoglycemia, not hyperglycemia.

Choice B rationale

While measuring the client’s vital signs is an important part of overall patient assessment, it does not directly address the client’s immediate issue of confusion and blurred vision after receiving a dose of glipizide.

Choice C rationale

Obtaining a fingerstick blood glucose level is the most appropriate action. The client’s symptoms of confusion and blurred vision are common side effects of glipizide, which is used to lower blood sugar levels in people with type 2 diabetes. These symptoms may indicate that the client’s blood sugar level is too low (hypoglycemia). Checking the blood glucose level will provide immediate information about the client’s current blood sugar level and guide further interventions.

Choice D rationale

Performing a neurological exam is not the most appropriate immediate response. While confusion and blurred vision can be symptoms of neurological issues, in this context, they are likely related to the client’s recent dose of glipizide.