Final answer:
To calculate total infusion time without a given rate in mL/hr, determine the flow rate in gtt/min by counting the drops and then multiply by the drop factor specific to the IV set. Convert this to mL/hr and divide as necessary for total time.
Step-by-step explanation:
To calculate the total infusion time for a fluid when the rate in mL/hr is not indicated, one common method used in healthcare settings is to first determine the flow rate in drops per minute (gtt/min). This can be done by timing the rate at which drops of fluid fall, typically through a drip chamber. Once you know the number of drops per minute, this can be compared to the specific drop factor of the IV tubing set (expressed as gtt/mL), which is a known property of the equipment being used. For example, if the packaging indicates a drop factor of 20 gtt/mL and you count 15 drops in one minute, the rate is 15 gtt/min. To find the flow rate in mL/hr, you multiply the gtt/min by 60 minutes. If further calculations are necessary to convert to a standard time unit like hours for total infusion time, additional arithmetic involving division may be pertinent.