A 1000 ml of 5% dextrose in water is to be infused over 8 hours. The infusion set delivers 15 drops per milliliter. The nurse should run the I.V. infusion at a rate of:

1. A

   15 drops per minute

2. B

   21 drops per minute

3. C

   32 drops per minute

4. D

   125 drops per minute

Appeared in: IGNOU PB Bsc Nsg.Entrance-2026

Explanation

• The standard formula for calculating IV drip rate is: Flow Rate (gtt/min) = (Total Volume in mL × Drop Factor) / Total Time in minutes.
• First, convert the infusion time from hours to minutes: 8 hours × 60 minutes/hour = 480 minutes.
• Substitute the given values into the formula: (1000 mL × 15 gtt/mL) / 480 minutes.
• The calculation results in 15000 / 480 = 31.25 drops per minute.
• Since a fraction of a drop cannot be administered, the rate is rounded to the nearest whole number. Among the given options, 32 drops per minute is the correct answer.

Why Other Options Were Wrong

• Option A: This rate is significantly slower than the calculated rate of 31.25 gtt/min and would result in under-infusion of the prescribed fluid.
• Option B: This rate is mathematically incorrect for the given parameters. It does not align with the standard IV drip rate formula.
• Option D: This value represents the hourly infusion rate in milliliters (1000 mL / 8 hours = 125 mL/hr), not the drop rate per minute. Confusing mL/hr with gtt/min is a common calculation error.

Related Visual

Clinical Relevance

• Nursing practice connection: Knowing IV Drip Rate Calculation helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
• Accurate calculation of IV flow rates is a fundamental nursing skill essential for patient safety. Incorrect rates can lead to fluid overload or dehydration.
• While electronic infusion devices (EIDs) are common, nurses must be able to perform manual calculations for situations where pumps are unavailable or during power outages.
• What if? If the infusion set was a microdrip (60 gtt/mL), the calculation would change. The rate would be (1000 mL × 60 gtt/mL) / 480 min = 125 drops/minute. This highlights the critical importance of verifying the drop factor on the equipment.

How to Approach the Question

• First, identify all the necessary components for the calculation from the question: Total Volume (1000 mL), Total Time (8 hours), and the Drop Factor of the infusion set (15 gtt/mL).
• Recognize that the formula requires time to be in minutes. Convert the total time from hours to minutes (8 hours × 60 min/hr = 480 minutes).
• Recall or look up the standard formula for IV flow rate: Flow Rate (gtt/min) = (Volume in mL × Drop Factor) / Time in minutes.
• Substitute the known values into the formula: (1000 × 15) / 480.
• Perform the mathematical calculation, which equals 31.25.
• Since the answer must be a whole number of drops, round the result to the nearest whole number and select the corresponding option.

Concept Tested & Keywords

• Concept Tested: IV Drip Rate Calculation
• Stem keywords: 1000 ml, 5% dextrose, 8 hours, infusion set, 15 drops per milliliter
• Lead-in keywords: rate of
• Negative lead-in flag: false

Question ID

Q4TPVFC50tgMJQzIMsJvqy

Copy ID

Reference Book

E6 Pharmacology Nurses Shanbhag 3e p. 54-56

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

E6 Nursing Fundamentals Taylor p. 799-801