Medical Surgical Labs Liver Labs #5

Question

The nurse is caring for a client with hepatic encephalopathy. She understands that assessing her client’s mental status is the best way to monitor her client’s ammonia levels. Which other key assessment is most appropriate for detecting increased ammonia levels?

Answers

  1. Observing for signs of jaundice.
    • Rationale:

      This answer is not correct because jaundice is not specific to hepatic encephalopathy. Jaundice is a result of increased levels of bilirubin in the body.

  2. Assessment of client's blood vessels.
    • Rationale:

      This answer is not correct because assessing for small veins is not specific to hepatic encephalopathy. Bleeding from varicose veins may indicate portal vein thrombosis.

  3. Watching for muscle twitching.
    • Rationale:

      This answer is not correct because although muscle twitching (myoclonus) is a sign of increased ammonia levels, the best way is to assess for asterixis. Asterixis is a tremor of the hand when the arm is extended.

  4. Assessing hand movement with arm extended.
    • Rationale:

      This answer is correct because aside from assessing mental status, it is the best way to assess for increased levels of ammonia. Asterixis is a tremor of the hand when the arm is extended. This disorder is caused by a decline in brain function.

Overview

The best way to assess for ammonia levels is by observing for mental status changes. The next best way is to assess for asterixis, by extending the arm and watching for a tremor in the hand.

Explanation

Learning Outcomes

Aside from assessing mental status, observing for hand movement when the arm is extended is the best way to assess for increased levels of ammonia. Asterixis is a tremor of the hand when the arm is extended. This disorder is caused by a decline in brain function. Muscle twitching (myoclonus) is also a sign of increased ammonia levels. Jaundice is a result of increased levels of bilirubin in the body and is not specific to hepatic encephalopathy. This is the same for small blood vessels or varicose veins. The key assessments are mental status changes and observing for asterixis.

Test Taking Tip

Remember the phrase “with arm extended” or “extension of the arm” when assessing for ammonia levels.

Video Rationale