Medical Surgical Head Injury #5

Question

The nurse is caring for a client with a head injury and his next dose of mannitol will be in two hours. The nurse receives lab results for the client revealing BUN 49 mg/dL, creatinine 19 mg/dL, Na 160 mEq/L, and a serum glucose of 19 mmol/L. Which should be the nurse’s priority action?

Answers

  1. Contact the provider with the lab results before administration of the drug.
    • Rationale:

      This answer is correct because the client’s labs reflect moderate dehydration. Mannitol is excreted in the urine with excess water, sometimes causing hypernatremia due to induced diuresis. For this reason, monitoring renal function is imperative during mannitol therapy.

  2. Wait two hours and have labs drawn again, then notify the provider of results.
    • Rationale:

      This answer is not correct because these labs reveal near critical levels and the provider should be notified immediately. Waiting two hours and having labs drawn again will only prolong the client’s problem and the solution.

  3. Administer the medication as prescribed by the provider.
    • Rationale:

      This answer is not correct because the labs show dehydration and administering mannitol as prescribed can cause renal damage and could be detrimental to the client’s health. By decreasing the demand for oxygen, mannitol can possibly cause ischemic renal injury.

  4. Titrate the dose of the medication to reflect the lab parameters.
    • Rationale:

      This answer is not correct because of the near critical lab values and the contraindication of mannitol with dehydration. The nurse should notify the provider always or consult the prescribed order before titrating medications.

Overview

Mannitol is an osmotic diuretic used to reverse acute brain damage by decreasing oxygen demand and relieving vascular congestion within the brain. This drug has multiple contraindications due to its potential to worsen renal function.

Explanation

Learning Outcomes

Mannitol is an osmotic diuretic used to reverse acute brain damage by decreasing oxygen demand and relieving vascular congestion within the brain. This drug has multiple contraindications due to its potential to worsen renal function. Mannitol is excreted in the urine with excess water, sometimes causing hypernatremia due to induced diuresis. For this reason, monitoring renal function and electrolytes closely is especially imperative during mannitol therapy. Mannitol should be discontinued until the provider is notified in the event of abnormal labs that indicate dehydration. This action by the nurse can decrease the risk of renal injury. Mannitol is contraindicated in severe dehydration, pulmonary edema, active intracranial bleeding, heart failure, and renal damage.

Test Taking Tip

Understand the contraindications of osmotic diuretics and how they may negatively affect renal function. Know lab values.

Video Rationale