Question

An IV of 1,000 mL is to infuse from 6 a.m. until 2 p.m. The drop factor is 15 gtt/mL. Calculate the flow rate.__________   

At 11 a.m. you notice that 750 mL has infused. Recalculate the flow rate for the remaining solution. _____________

Does it fall within the safe range for recalculating an IV flow rate? ________

Answer 1

If electronic infusion controllers  are used, flow  rate is calculated.

Flow rate = Volume (ml) / Time (hours)

Volume (ml) = 1000

Time (hours) = 8

Flow rate = 1000/ 8 = 125 ml

The nurse has to infuse IV fluid at 125 ml/ hour or 2ml / minute

[ If manual infusion controllers are used, drop rate is calculated as follows

Drop rate = Amount of solution to be infused (ml) x Drop factor

Time in minutes

Amount of solution to be infused (ml) = 1000 ml

Drop factor = 15 gtt / ml

Time = 8 hours ( 6 am - 2 pm ) i.e 8 x 60 = 480 minutes

Flow rate = 1000 x 15 = 31.25

480

The nurse has to infuse IV fluid at 31 drops per minute.]

Recalculation of flow rate at 11am

Amount of solution to be infused (ml) = 250 ml ( remaining fluid)

Time = 3 hrs ( 11am - 2 pm)

Flow rate = Volume (ml) / Time (hours) = 250 / 3 = 83.33 ie 83 ml per hour. or 1ml / minute

[ drop rate = 250x 15 = 20.83 i.e 21 drops per minute]

180

In this case, the fluid was infused at a faster rate.

At 11 am ,the fluid that has to be infused was 625 ml (125 ml/hour x 5 hrs) and 375 ml should remain   in the bag .

But 750 ml of fluid got infused by 11 am and remaining fluid was 250 ml.

Fast IV fluid infusion ( without proper indication) may result in fluid overload especially in vulnerable patients. Hence it is not a safe pratice.

Recalculatiion of  an IV flow rate is not considered as a safe practice because it is a nursing negligence.A prudent and licensed nurse is expected to calculate the correct flow rate before initiation of an IV infusion.