Question

The doctor orders 1 litre of normal saline for 8 hours. The drop factor is 20 gtts/ml. What is the flow rate?

Answer 1

The flow rate for an IV to deliver 1 litre of normal saline over 8 hours with a drop factor of 20 gtts/mL is calculated to be 41.67 drops per minute.

Step-by-step explanation:

The student is asking how to calculate the flow rate for an IV (intravenous) drip of normal saline, prescribed by a doctor to be infused over 8 hours, given a specific drop factor of the IV system. To find the flow rate in drops per minute (gtts/min), we can use the formula:

1. First, convert the total volume to be infused into milliliters (mL). In this case, it is already in mL, as 1 litre is 1000 mL.
2. Next, calculate the total time in minutes. Since there are 60 minutes in an hour, 8 hours corresponds to 480 minutes.
3. Finally, apply the formula: Flow rate = (Volume (mL) × Drop factor (gtts/mL)) ÷ Time (min)

Using the provided volume and drop factor, we find:
Flow rate = (1000 mL × 20 gtts/mL) ÷ 480 min

Flow rate = 20000 gtts ÷ 480 min

Flow rate = 41.67 gtts/min (rounded to two decimal places)

Therefore, the IV should be set to a flow rate of 41.67 drops per minute to deliver 1 litre of normal saline over the course of 8 hours with a drop factor of 20 gtts/mL.