# IV Microdrop flow rate question.

by Germaine
(LA) IV Microdrop Calculation

Please show how to calculate this IV problem:

The medication order is to administer dobutamine hydrochloride (Dobutrex) at 5.2 mcg/kg/min. The patient weighs 150 lbs. The IV solution has been prepared by adding Dobutrex 250 mg to 200 mL of D5W. Calculate the flow rate in microdrops (60 drops per mL).

### Comments for IV Microdrop flow rate question.

 IV Question Answer by: ANA PATIENT SHOULD ADMINISTER:.354mg/min (.0052mg *68.18 kg)we have 250mg /200 ml so,345mg found in 283 ml the drop factor = 60 gtt/ml so we have 17.07gtt/283 ml so the flow rate is 17gtt/min

 help by: Anonymous doesnt make sense? :(

 hope this helps by: Anonymous First step convert mcg to mg. 5.2mcg to .0052mg. Then convert lbs. to kg 150/2.2= 68.18(to convert lbs. to kg divide by 2.2)Next .0052mg x 68.18kg= .354MLPlug that into your concentration 250mg/200mlx .354=.283now micro drip is 60. so multiply .283 by 60.283x60=

 hope this helps by: Anonymous First step convert mcg to mg. 5.2mcg to .0052mg. then convert lbs. to kg 150/2.2=68.18 (to convert lbs. to kg you must divide lbs. by 2.2)next .0052mgx 68.18kg=.354mlPlug that into your concentration 250mg/200mlx.354=.283Now micro drip is 60. So .283x60=1717gtts/min

 microdop flow rate by: Anonymous First step convert mcg to mg. 5.2mcg to .0052mg. then convert lbs. to kg 150/2.2=68.18 (to convert lbs. to kg you must divide lbs. by 2.2)next .0052mgx 68.18kg=.354mlPlug that into your concentration 250mg/200mlx.354=.283Now micro drip is 60. So .283x60=1717gtts/min

 Drop factor calculation by: Anonymous You need to use like (same units):150 lbs * (1kg/2.2lbs) = 68.2 kgMultiply the ordered rate in mcg/kg/min by patient weight:68.2 kg * 5.2 mcg/kg/min= 354.64 mcg/minConvert mcg to mg: (Move decimal 3 places to left or:)364.64 mcg/min * (1mg/1000mcg)= 0.365 mg/minNeed to use concentration of bag to convert dose to ml:0.365 mg/min * (200 ml/250mg)= 0.292 ml/minConvert ml/min using drop factor:0.292 ml/min * (60 drops/1ml) = 17.5 drops/min

 really confused by: Anonymous This is one of the most confusing ones what is a easier way to remember the formula

 hope this helps by: Johnson Meloottu CPhT First of all, we need to convert two things. -First one is mcg to mg. That is 5.2mcg/1000 = 0.0052mg-Second pound to kg. That is 150/2.2 = 68.18kgThe total mL = .0052mg(68.18kg)= 0.354mgConcentration given is 250mg/200 ml.so 200 ----(.354) = 283ml 250micro drip is 60gtt/mLSo the flow rate = .283mL(60)= 17gtt/min

 All in one step method by: Brad Wojcik, Pharm D You can do this all in one step using dimensional analysis. You are starting with a rate of 5.2 mcg/kg*min for a 150 lb pt and have to end up with microdrops/min. 150 lb(5.2 mcg/kg*min)(1 kg/2.2 lb)(200 mL/250 mg) 1 mg/1000 mcg)(60 microdrops/mL) = 17 microdrops/min.I like this method because you can cancel out all the unwanted units making sure that you are ending up with the correct units before you do any calculations.