If 2000 ml of normal saline is to be infused in 24 hours, then how many drops need to be infused per minute? The drop factor is 15 macro drops/ml?

1. A

   26 drop/min

2. B

   27 drop/min

3. C

   21 drop/min

4. D

   31 drop/min

Appeared in: JIPMER Pondicherry NO - 2022

Explanation

• derived by applying the standard formula for IV drip rate calculation.
• First, convert the total infusion time from hours to minutes: 24 hours × 60 minutes/hour = 1440 minutes.
• Next, use the formula: Flow Rate = (Total Volume × Drop Factor) / Total Time in minutes.
• Substitute the given values: (2000 mL × 15 gtt/mL) / 1440 min.
• The calculation yields 30,000 / 1440 = 20.833 gtt/min.
• Since drops must be whole numbers, the result is rounded to the nearest whole number, which is 21 drops/min.

Why Other Options Were Wrong

• Option A: This value is incorrect and likely results from a miscalculation, possibly by dividing the total drops (30,000) by an incorrect time value, such as using 20 hours (1200 minutes) instead of 24, which would give 25 gtt/min, or another mathematical error.
• Option B: This is an incorrect calculation. It may arise from errors in multiplication or division during the calculation process.
• Option D: This value is incorrect. It might be obtained if the total volume was divided by a much shorter time frame, leading to a significantly higher drip rate.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain IV Drip Rate Calculation as background academic context rather than a clinical decision trigger.
• Accurate calculation of IV flow rates is a critical nursing skill to ensure patient safety. Incorrect rates can lead to fluid overload, dehydration, or improper medication delivery.
• Nurses must be familiar with both macrodrip (for routine or rapid infusions) and microdrip (for pediatric or high-potency medication infusions) sets and their respective drop factors.
• What if? If the order was for a microdrip set (60 gtt/mL) instead of a macrodrip set, the calculation would be (2000 mL × 60 gtt/mL) / 1440 min = 120,000 / 1440 = 83.33, which rounds to 83 gtt/min. This demonstrates how the drop factor significantly alters the flow rate.

How to Approach the Question

• First, identify all the necessary components for the calculation provided in the question: total volume (2000 mL), total time (24 hours), and the drop factor (15 gtt/mL).
• Recognize that the required answer is in 'drops per minute'. This means you must convert the total time from hours to minutes.
• Recall or look up the standard formula for IV drip rate: Flow Rate = (Volume × Drop Factor) / Time in minutes.
• Perform the time conversion: 24 hours × 60 min/hour = 1440 minutes.
• Substitute the values into the formula: (2000 × 15) / 1440.
• Calculate the result and remember to round to the nearest whole number, as partial drops cannot be administered.

Concept Tested & Keywords

• Concept Tested: IV Drip Rate Calculation
• Stem keywords: 2000 ml, normal saline, 24 hours, drops per minute, drop factor, 15 macro drops/ml
• Lead-in keywords: how many

Question ID

QtOzlVDr32gq8h1TkJZqZA

Copy ID

Reference Book

E6 Pharmacology Nurses Shanbhag 3e p. 54-56

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 93-95