The doctor has ordered 500 ml 5% dextrose to be administered for 5 hours. It should be administered using a burette set. The nurse has to set the drops per minute to deliver the appropriate amount. Calculate the flow rate?

1. A

   100 microdrops per minute

2. B

   60 microdrops per minute

3. C

   100 macrodrops per minute

4. D

   60 macrodrops per minute

Appeared in: AIIMS Rishikesh & Jodhpur NO - 2017

Explanation

• The calculation requires the formula: Flow Rate = (Volume × Drop Factor) / Time in minutes.
• A burette set is a microdrip system, which has a standard drop factor of 60 gtt/mL.
• The total volume is 500 mL, and the time is 5 hours (300 minutes).
• Plugging the values into the formula: (500 mL × 60 gtt/mL) / 300 min = 100 gtt/min.
• Because it is a microdrip set, the unit is 'microdrops', making the correct answer 100 microdrops per minute.

Why Other Options Were Wrong

• Option B: This is an incorrect calculation. A rate of 60 microdrops per minute would deliver only 300 mL over 5 hours, not the prescribed 500 mL.
• Option C: This option uses the correct numerical value (100) but the wrong type of drop ('macrodrops'). A burette set is a microdrip system, not a macrodrip system.
• Option D: This option has both an incorrect numerical value (60) and the wrong type of drop ('macrodrops').

Related Visual

Clinical Relevance

• Nursing practice connection: Knowing IV flow rate calculation helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
• Accurate IV flow rate calculation is a critical nursing skill to prevent fluid overload or under-hydration, and to ensure medications are delivered at the correct therapeutic rate.
• Burette sets (microdrip) are essential in pediatrics and for administering potent medications where precision is paramount to avoid overdose.
• What if the order was for a trauma patient needing rapid fluid resuscitation? The nurse would use a macrodrip set (e.g., 10 gtt/mL) and the flow rate would be much higher to deliver volume quickly. For 500 mL in 30 minutes, the rate would be (500 * 10) / 30 = ~167 gtt/min.

How to Approach the Question

• First, identify that this is an IV flow rate calculation question.
• Identify the key pieces of information given: Total Volume (500 mL), Total Time (5 hours), and the type of IV set ('burette set').
• Recognize that a 'burette set' is a microdrip set, which has a drop factor of 60 gtt/mL.
• Convert the total time from hours to minutes (5 hours × 60 = 300 minutes).
• Apply the standard formula: Rate = (Volume × Drop Factor) / Time in minutes.
• Calculate the result: (500 × 60) / 300 = 100. Match this with the options, ensuring the drop type (microdrops) is correct.

Concept Tested & Keywords

• Concept Tested: IV flow rate calculation
• Stem keywords: 500 ml, 5% dextrose, 5 hours, burette set, calculate flow rate
• Lead-in keywords: Calculate
• Clinical cues: The use of a 'burette set' is a key clinical cue, as it specifies a microdrip system with a drop factor of 60 gtt/mL.

Question ID

Qgkvi04N1cK6GX6hZ5ze48

Copy ID

Reference Book

E6 Pharmacology Nurses Shanbhag 3e p. 54-56

E6 Nursing Fundamentals Taylor p. 799-801