A patient with increased intracranial pressure is receiving mannitol. To evaluate the effectiveness of this drug, the nurse should assess the client for which of the following?

1. A

   Decreased pulse rate

2. B

   Increased temperature

3. C

   Increased urine output

4. D

   Increased papillary reaction

Appeared in: AIIMS Bhatinda NO - 2019

Explanation

• Mannitol is an osmotic diuretic that reduces cerebral edema by pulling fluid from the brain tissue into the vascular space.
• This action increases the volume of fluid that is filtered by the kidneys and excreted from the body.
• A marked increase in urine output (diuresis) is the direct therapeutic effect and the key indicator that the drug is working as intended to lower intracranial pressure.

Why Other Options Were Wrong

• Option A: A decreasing pulse rate (bradycardia) is a component of Cushing's triad, a sign of worsening or very high ICP. It is not a sign of effective treatment.
• Option B: Mannitol does not directly affect body temperature. An increased temperature in a neuro patient is a concern as it increases metabolic demand and can worsen ICP.
• Option D: While improved pupillary reaction is a desired outcome of reducing ICP, it is an indirect and less immediate measure of the drug's effect compared to urine output.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Monitoring the therapeutic effect of Mannitol for increased intracranial pressure to guide bedside assessment, documentation, and the next nursing action.
• Nurses must perform strict intake and output monitoring for patients on mannitol, often on an hourly basis. A target urine output is typically 30-50 mL/hr or higher.
• Monitoring serum osmolality is critical. If it exceeds a threshold (e.g., 320 mOsm/kg), the drug is usually held to prevent acute kidney injury and other complications.
• What if? If the patient's urine output decreases or is minimal after mannitol administration, the nurse must immediately suspect that the drug is not effective and may be causing rebound cerebral edema or acute kidney injury. This is a critical finding to report to the provider.

How to Approach the Question

• First, identify the core of the question: How to measure the effectiveness of a specific drug (mannitol).
• Recall the drug class and mechanism of action. Mannitol is an osmotic diuretic.
• Connect the mechanism to a measurable outcome. The term 'diuretic' itself implies an increase in urine production. The osmotic action explains how it achieves this by drawing fluid out of tissues.
• Evaluate the given options based on this primary mechanism. Increased urine output is a direct and expected result of the drug's action.
• Rule out the other options by considering if they are direct effects of the drug or are related to the underlying condition (ICP). For example, changes in pulse rate and pupils are signs of ICP itself, not direct effects of the medication.

Concept Tested & Keywords

• Concept Tested: Monitoring the therapeutic effect of Mannitol for increased intracranial pressure.
• Stem keywords: increased intracranial pressure, mannitol, evaluate effectiveness
• Lead-in keywords: assess for which of the following
• Clinical cues: Patient with increased intracranial pressure
• Clinical cues: receiving mannitol

Question ID

QcqoqVAgNLDjyPA5fSt-RT

Copy ID

Reference Book

E6 Nursing Brunner Adult Health 3SA Vol 2 Part 2 pp. 37-39, 38-40