If a physician orders 1 unit of whole blood (500 mL) to infuse over 4 hours with a drop factor of 10 gtt/mL, what is the flow rate in gtt/min?

To determine the flow rate in gtt/min for the infusion of 1 unit of whole blood (500 mL) over 4 hours, you'll first need to convert the total infusion time into minutes, as flow rates are commonly calculated in terms of drops per minute.

Since 4 hours equals 240 minutes (4 hours x 60 minutes/hour), the next step is to calculate the total number of drops that will be delivered during the infusion. The drop factor is given as 10 gtt/mL. So, for 500 mL of blood, the total number of drops is calculated as follows:

500 mL x 10 gtt/mL = 5000 gtt.

To find the flow rate in gtt/min, you then divide the total number of drops (5000 gtt) by the total infusion time in minutes (240 min):

5000 gtt ÷ 240 min = approximately 20.83 gtt/min.

Rounding this to one decimal place gives you 20.8 gtt/min. This calculation aligns with the correct response and provides a clear understanding of how to derive the flow rate using the provided values for volume, time, and drop factor.