VSSC Nursing Officer - 2021
Pharmacology
Hard

The following should be specifically monitored for administering IV mannitol safely?

Appeared in: VSSC Nursing Officer - 2021

Explanation

  • Mannitol is an osmotic diuretic that pulls fluid into the vascular space and increases urine production.
  • Hourly urine output is the most direct and immediate indicator of the drug's effectiveness and the patient's renal response.
  • A target urine output of at least 0.5 mL/kg/hr (or 30-50 mL/hr for an adult) confirms adequate kidney perfusion and function.
  • Failure to produce sufficient urine after a mannitol dose can lead to fluid overload, pulmonary edema, and heart failure, making hourly monitoring a critical safety measure.

Why Other Options Were Wrong

  • Option A: Monitoring vital signs every four hours is too infrequent for a potent medication like mannitol. Fluid shifts can cause rapid changes in blood pressure and heart rate that require more frequent assessment, especially during initial administration.
  • Option B: Daily body weight is a good indicator of long-term fluid balance but is not sensitive enough for immediate safety monitoring during a mannitol infusion. Significant and dangerous fluid shifts can occur within hours.
  • Option C: If mannitol is administered for increased intracranial pressure, the level of consciousness should be monitored much more frequently than every 8 hours (typically hourly). An 8-hour interval would miss critical changes in neurological status.

Related Visual

An infographic illustrating the mechanism of action of mannitol, showing how it pulls fluid from the brain and tissues into the blood vessels and is then filtered by the kidneys...
Clinical Relevance
  • Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Safe administration and monitoring of IV mannitol as background academic context rather than a clinical decision trigger.
  • A nurse's primary responsibility during mannitol administration is to ensure patient safety by closely monitoring for both therapeutic effects and adverse reactions.
  • Failure to monitor urine output hourly can lead to delayed recognition of acute kidney injury or fluid overload, resulting in life-threatening complications like pulmonary edema.
  • What if? If a patient's urine output drops to less than 30 mL/hr for two consecutive hours after receiving mannitol, the nurse must stop the infusion immediately and notify the physician, as this indicates renal dysfunction and a high risk of systemic fluid overload.
How to Approach the Question
  • First, identify the drug in the question: IV mannitol.
  • Recall the drug's class and primary action: Mannitol is an osmotic diuretic, designed to rapidly increase urine output.
  • Consider the implications of this action. The most direct way to measure the effect and safety of a powerful diuretic is to measure what it produces: urine.
  • Evaluate the options based on frequency and relevance. Hourly monitoring of urine output directly correlates with the drug's peak effect and provides the most immediate safety data.
  • Eliminate other options by assessing their frequency. Four-hourly, daily, and eight-hourly checks are too infrequent to safely manage the rapid fluid shifts caused by mannitol.
Concept Tested & Keywords
  • Concept Tested: Safe administration and monitoring of IV mannitol.
  • Stem keywords: IV mannitol, monitored, safely
  • Lead-in keywords: specifically
  • Negative lead-in flag: false

Question ID

Q3WeFDx5F10LUS5amIayEw

Reference Book

E6 Nursing Vital Signs pp. 114-116, 154-156

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 575-577

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