# iv calcualtions... again

1. here i am needing help w/ iv calculations again! any help/advice would be greatly appreciated!! here's my problem:
add 10,000 units of heparin to 500 mL D5W and infuse @ 100 unit/hr
calculate the flow rate in ml/min

i also need some assistance here too cuz i have no clue where to start on this one!:
dobutamine 250 mg in 250 ml of D5W at 3.5 mcg/kg/min. determine rate in mcgtt/min for pt who weighs 120 lbs.

THANK YOU!!!!!!!
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3. Quote from ilovematt48
here i am needing help w/ iv calculations again! any help/advice would be greatly appreciated!! here's my problem:
add 10,000 units of heparin to 500 mL D5W and infuse @ 100 unit/hr
calculate the flow rate in ml/min

i also need some assistance here too cuz i have no clue where to start on this one!:
dobutamine 250 mg in 250 ml of D5W at 3.5 mcg/kg/min. determine rate in mcgtt/min for pt who weighs 120 lbs.

THANK YOU!!!!!!!
On the first one. The ratio is 20 units per ML.
100/20 gives 5ml per hour. Divide by 60 and you get 0.08333333 or 8.3 mcg per minute.

250mg/250ml = 1mg per 1ml
120# = 54.545Kilo
54.545 * 3.5 mcg = 190.90 MCG per minute
Then you need to know the type of tubing you have. Divide that into the above..

Hope that helps more than it confuses....
4. first off, i work these problems in dimensional analysis which you really should learn to do. it will make your life a whole lot better in calculating these problems. it is also known as the factor/label method. you can find short tutorials on dimensional analysis on post #3 of this thread:

Quote from ilovematt48
add 10,000 units of heparin to 500 ml d5w and infuse @ 100 units/hour. calculate the flow rate in ml/min.
dose desired: 100 units/hour
dose on hand: 10,000 units/500 ml
conversion factor: 60 minutes = 1 hour

100 units/1 hour (dose desired) x 500 ml/10,000 units (dose on hand) x 1 hour/60 minutes (conversion factor) = 0.08333 ml/minute, rounded off to 0.08 ml/minute

Quote from ilovematt48
dobutamine 250 mg in 250 ml of d5w at 3.5 mcg/kg/min. determine the rate in microdrops/min for a patient who weighs 120 lbs.
dose desired: 3.5 mcg/kg/minute
dose on hand: 250 mg/250 ml
patient weight: 120 pounds
conversion factor: 1 kilogram = 2.2 pounds
conversion factor: 1 milligram = 1000 micrograms
you must know that microdrop tubing delivers 60 drops/1 ml

3.5 mcg/1 minute (dose desired) x 250 ml/250 mg (dose on hand) x 120 pounds/2.2 pounds (patient weight conversion to kg) x 60 gtts/1 ml (drop factor of iv tubing) x 1 mg/1000 mcg (conversion factor) = 11.45 drops/minute, rounded off to 11 drops/minute (a drop cannot be a fractional part)
Last edit by Daytonite on Jan 21, '08

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