Patient with increased ICP is receiving Inj. Mannitol. The nurse's understanding about the reason for adminis… - JIPMER Pondicherry NO - 2022

JIPMER Pondicherry NO - 2022

Medical Surgical Nursing

Medium

Appeared in: JIPMER Pondicherry NO - 2022

Explanation

Mannitol is an osmotic diuretic that increases the osmolarity (solute concentration) of the blood plasma.
This creates a powerful osmotic gradient that pulls excess water from the brain tissue (parenchyma) across the blood-brain barrier and into the bloodstream.
This reduction in brain volume and cerebral edema directly leads to a decrease in intracranial pressure (ICP).
The primary therapeutic goal for using Mannitol in this context is this specific fluid shift from the brain, not simply increasing urine output.

Option A: Reducing the secretion of cerebrospinal fluid (CSF) is the mechanism of action for a different class of drugs, carbonic anhydrase inhibitors.
Option B: While Mannitol does cause significant diuresis (increased urine output), this is a secondary effect or result of its primary action. The main reason for its use in this context is to reduce brain swelling.
Option D: This statement describes the opposite of the drug's intended effect. Mannitol's osmotic action is specifically designed to decrease, not increase, intracranial pressure.

Clinical Relevance

Nursing practice connection: Use the key finding related to Mechanism of action of Mannitol in managing increased intracranial pressure (ICP) to guide bedside assessment, documentation, and the next nursing action.
Administering Mannitol is a critical intervention for managing life-threatening cerebral edema and increased ICP. Nurses must monitor neurological status closely to assess its effectiveness.
A key patient safety responsibility is to always use an in-line filter during administration, as Mannitol can crystallize at room temperature, which could cause a serious vascular embolism if infused.
Nurses must closely monitor fluid balance, including hourly urine output and serum electrolytes/osmolality, to prevent dehydration, electrolyte imbalances, and acute kidney injury.

How to Approach the Question

First, identify the core of the question: it asks for the primary reason or mechanism of action for giving Mannitol to a patient with increased ICP.
Analyze the drug class: Mannitol is an osmotic diuretic. The term 'osmotic' is the most important clue to its mechanism.
Evaluate the options based on this classification. Option C directly links the osmotic effect to a decrease in ICP, which aligns perfectly with the drug's class and the patient's condition.
Consider the other options. While increased urine output (Option B) is a known effect, is it the reason for treating ICP? The primary problem is brain swelling, so the solution must address that directly.
Eliminate options that describe the wrong mechanism (Option A, which is for drugs like acetazolamide) or the opposite effect (Option D).
Conclude that the most precise answer is the one that describes the direct effect on the brain tissue via osmosis to reduce pressure.

Concept Tested & Keywords

Concept Tested: Mechanism of action of Mannitol in managing increased intracranial pressure (ICP).
Stem keywords: increased ICP, Mannitol, reason for administration
Lead-in keywords: reason for administration
Clinical cues: Patient with increased ICP
Negative lead-in flag: false

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