IV Flow Rate Calculation
Summary of IV Flow rate calculation
-Gravity flow rates are counted in gtt/min. -IV tubings are calibrated in gtt/mL. -Macrodrip IV sets are calibrated at 10, 15, or 20 gtt/mL. -Mini or microdrip sets have a calibration of 60 gtt/min. -IV infusions are ordered as mL/hr or mL/min.
An IV of 2000 mL NS is to infuse over 12 hr using a 10 gtt/mL set.
2000/12 = 167 mL/hour Flow rate = 167 mL per hour x 10 gtt per mL / 60 min = 27.83 gtt/min = 28 gtt/minute
3500 mL are ordered to infuse in 24 hr using a set calibrated at 20 gtt/mL
3500/24 = 146 mL/hour Flow rate = 146 mL per hour x 20 gtt per mL / 60 min = 48.66 gtt/min = 49 gtt/min
A nurse is preparing to administer D5LR 500 ml IV to infuse over 4 hours. The nurse should set the infusion pump to deliver how many mL/hr?
500 mL / 4 hour = 125 mL/hour
Infuse 500 mL in 3 hour using a 15 gtt/mL set
500/3 = 166.67 = 167 mL/hour Flow rate = 167 mL/hour x 15 gtt per mL / 60 min = 41.75 gtt/min = 42 gtt/min
Order: LR 750 ml IV to infuse over 6 hours. The nurse should set the IV pump to deliver how many mL/hr? (Round to the nearest whole number.)
750 mL / 6 hour = 125 mL/hour
An IV solution is ordered at 200 mL/hr using a set calibrated at 15 gtt/mL
Flow rate = 200 mL per hour x 15 gtt per mL / 60 min = 50 gtt/min
Small-volume orders usually involved medication administration and should be infused per...
PUMP
Calculating by Amount and Time mL/hour
Volume (mL) / Time(hr) = x(mL/hr)
Calculate flow rate
Volume of infusion in ml x drip factor = flow rate time of infusion in minutes (gtt/min)
Large volumes administered at
mL/hour ¤If no pump is being used, the most common calculation involves conversion of an I.V. order to the (drops/minute) gtt/min rate necessary to infuse it. Will count by gtt/min. by gravity
Macrodrip
used for routine adult IV admins 10, 15, or 20 gtt/mL
Microdrip
when more exact measurements are needed to infuse med or in critical care and pediatric infusions on a pump (60 gtt/mL)
What if calculated flow rate has a decimal?
¤Some I.V. pumps allow for decimal input. ¤If not, see your institution/agency protocol. ¤Follow rules of rounding: 0.5 or greater round up to the next highest number. <0.5 round down to the next lowest number.
Administer an IV of 110 mL/hr using a set calibrated at 20 gtt/mL.
¨Flow rate = 110 x 20 60 min. = 2200 2200/60 minutes = 36.6 gtt/min = 37 gtt/min
