7/30/2019 IV Calculation

1/6

TO CALCULATE RATE USING MINUTES

volume x calibrationminutes

= gtt/min

TO CALCULATE RATE USING HOURS

volume x calibrationhours x 60

= gtt/min

1) Give a 50cc IVPB over 30 minutes using IV tubing with a calibrationof 10. How many drops per minute should this IVPB be set for? Seethe example below.

select "x = minutes"x = 30volume = 50calibration = 10

Actual formula:

50 x 1030

= 16.7 or 17 g

2) Using IV tubing alone (calibrated at 60), prepare an IV to infuse 1liter over 8 hours. How many drops per minute should the IV be setfor? See the example below.

select "x = hours"x = 8

volume = 1000calibration = 60

Actual formula:

1000ml x 608 x 60

= 125 gtt/min

7/30/2019 IV Calculation

2/6

Note, when using microdrip tubing (calibration = 60), the drip rate will bethe same as mL/hr. This will save you the time of calculating the driprate if asked to give the rate in mL/hr.

3) The doctor orders an IV to infuse at 125cc/hr. Calculate the flow rateusing 10 drop/min IV tubing.

select "x = milliters/hour"x = 125calibration = 10

Actual formula:

125cc x 1060 = 20.8 or 21 gtt/min

7/30/2019 IV Calculation

3/6

How to calculate IV flow rates:

Intravenous fluid must be given at a specific rate, neither too fast nor too slow. Thespecific rate may be measured as ml/hour, L/hour or drops/min. To control or adjust the

flow rate only drops per minute are used.

The burette contains a needle or plastic dropper which gives the number of drops per ml(the drop factor). A number of different drop factors are available (determined by the

length and diameter of the needle).

Common drop factors are:10 drops/ml (blood set), 15 drops / ml (regular set), 60 drops / ml (microdrop).

To measure the rate we must know:(a) the number of drops

(b) time in minutes.

The formula for working out flow rates is:

volume (ml) X drop factor (gtts / ml)---------------------------------------------

time (min)

= gtts / min(flow rate)

Example:

1500 ml IV Saline is ordered over 12 hours. Using a drop factor of 15 drops / ml, howmany drops per minute need to be delivered?

1500 (ml) X 15 (gttss / ml)---------------------------------------------------

12 x 60 (gives us total minutes)= 31 gtts / minute

7/30/2019 IV Calculation

4/6

7/30/2019 IV Calculation

5/6

7/30/2019 IV Calculation

6/6