A nurse is preparing to administer Ringer’s lactate 500 mL IV bolus to infuse over 3 hr. The drop factor of the manual IV tubing is 20 gtt/mL. The nurse should set the manual IV infusion to deliver how many gtt/min? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
The correct answer and Explanation is :
To calculate the IV flow rate in gtt/min (drops per minute), the following formula is used:
[
\text{Flow Rate (gtt/min)} = \left( \frac{\text{Volume to be infused (mL)} \times \text{Drop factor (gtt/mL)}}{\text{Time (minutes)}} \right)
]
Step-by-Step Calculation:
- Identify the values:
- Volume to be infused: 500 mL
- Drop factor: 20 gtt/mL
- Time: 3 hours = 3 × 60 minutes = 180 minutes
- Apply the formula:
[
\text{Flow Rate (gtt/min)} = \left( \frac{500 \times 20}{180} \right)
]
[
\text{Flow Rate (gtt/min)} = \left( \frac{10,000}{180} \right)
]
[
\text{Flow Rate (gtt/min)} ≈ 55.56
] - Round to the nearest whole number:
- The flow rate is approximately 56 gtt/min.
Explanation:
The goal is to ensure that the prescribed amount of fluid (500 mL) is delivered evenly over the prescribed time (3 hours). Ringer’s lactate is typically used to replace fluids and electrolytes, and accurate flow rates are essential to ensure the patient receives the correct volume without under- or over-hydration.
The manual IV infusion tubing has a drop factor of 20 gtt/mL, meaning for every milliliter of fluid, 20 drops must be delivered. By calculating how many milliliters are infused over the prescribed time, we can then convert that volume into the number of drops needed per minute, thus allowing the nurse to set the IV accurately.
The final flow rate, 56 gtt/min, ensures that the nurse administers the fluid within the specified time frame, promoting safe and effective patient care.